11 BMW 1983 R100RS Install Crankshaft, Adjust End Float, Install Camshaft

Let me start this write-up with a WARNING, followed by a DANGER

WARNING:
I am not a professionally trained BMW mechanic and I have never had the opportunity to attend a BMW motorcycle mechanic training course on this work. Now you know my qualifications, read the following with this in mind.

That said, I did receive instructions from two long time BMW mechanics that were essential in helping me understand how to do this work so I could reduce my risk of permanently damaging the engine. But, even with these expert instructions, as I show below, I made several mistakes in technique and had to redo my work more than once to correct these mistakes. But, that’s all part of getting educated. 🙂

Setting the crankshaft end float is not a quick procedure and requires careful attention to detail along with good mechanical assembly and precision measurement skills. It requires a very clean working environment since you will be working with clearances on the order of the thickness of a human hair and you will be making adjustments to clearances at a fraction of that thickness. Therefore:

*** DANGER: DO NOT ATTEMPT TO DO THIS WORK UNLESS … ***

  • You have done all the engine work I show on my web site on multiple airheads,
  • You have an inside shop to work in that is clean,
  • You have the required tools,
  • You can make precise measurements as small as 0.002 mm (0.0001 inch), and
  • You are detail oriented, patient, and willing to redo work that is not up to par.

To put it simply, doing this work incorrectly will damage your engine, likely catastrophically.

Consider This Fair Warning.

What Getting It Wrong Look Like

Not My Crankshaft But A Reminder Of What Getting It Wrong Could Look Like

I removed the crankshaft to have the main bearings inspected. I had the rear main bearing replaced. You can read about how I remove the crankshaft here.

I believe that whenever you have removed the crankshaft and changed a main bearing, you should check the crankshaft end float to be sure it’s within the acceptable range. Not doing that risks destroying the engine.

Tools

I use my clamping dial indicator from Harbor Freight that combines a dial indicator with a pair of vice grips and an adjustable goose neck.

Harbor Freight Clamping Dial Gauge Tool

Harbor Freight Clamping Dial Gauge Tool In Its Box

Harbor Freight Clamping Dial Indicator Tool

Harbor Freight Clamping Dial Indicator Tool

The indicator supplied by Harbor Freight measures to 0.001 inch. For this work, I changed it to one that measures to 0.0005 in.

Harbor Freight Dial Indicator-0.001 Inch

Harbor Freight Dial Indicator-0.001 Inch

Dial Indicator-0.0005 Inch

Dial Indicator-0.0005 Inch

I need to heat the aluminum engine block to 250 F. This requires a lot of heat at a high temperature. I use a pair of Bernzomatic MAP-Pro torches that you can find at ACE, Home Depot and other home improvement or hardware stores. This torch is hotter than propane.

WARNING
Propane torches are not right for this work.  You need high heat, such as provided by two MAP-Pro torches, to get the aluminum engine block up to temperature quickly to minimize heating the crankshaft so you can keep it as cool as possible.

Bernzomatic MAP-Pro Torch Kit

Bernzomatic MAP-Pro Torch Kit

Two MAP-Pro Torches Required To Heat The Engine Block Around The Front Bearing Carrier to 250 F

Two MAP-Pro Torches Required To Heat The Engine Block Around The Front Bearing Carrier to 250 F

I measure the thrust washers with a micrometer that can measure 0.0001 inch, as in one ten-thousandth of an inch. This level of precision turned out to be important to get the end float adjusted to the value I wanted.

0-1 Inch Micrometer, Mitytoyo 0.0001 Inch

0-1 Inch Micrometer, Mitutoyo with 0.0001 Inch Accuracy

I use Permatex Ultra Slick engine assembly lube to lubricate various parts before I assemble them. This is critical since it takes time for oil to flow and lubricate the main bearings and thrust washer faces. The assembly lube provides lubrication until the oil can do it’s job so these parts aren’t damaged on the first engine start.

Permatex Ultra Slick Engine Assembly Lube

Permatex Ultra Slick Engine Assembly Lube DOES NOT GO ON THE CRANKSHAFT JOURNAL

What Is End Float?

So, what is end float, or end play as it also called? It’s a measurement of the amount of crankshaft axial movement (forward-backward) at room temperature. Crankshaft end float is critical to engine health and longevity. If the end float is too small, then the crankshaft will bind when the engine gets hot. If the end float is too large the clutch can be grabby or slip under high load or high speed.

And, although no shop manuals state this, the end float has to be measured with clean and dry (no oil) contact surfaces between the thrust washers and the thrust washer bosses on the crankshaft journals and the rear of the engine block. This is absolutely critical for correctly measuring the end float.

My Work Plan

I will start with the original inside and outside thrust washers to see if they give me the correct end float. If they don’t, I’ll change the outside thrust washer to a different thickness to get the desired end float.

BMW’s publishes the range of acceptable end float as 0.08 to 0.15 mm (0.0031 – 0.0059 inches). But, the recommendation from Tom Cutter at Rubber Chicken Racing Garage is to keep the end float between 0.08 – 0.12 mm (0.0031 – 0.0047 inches). He likes to set it as close to 0.10 mm (0.0039 inches) as possible.

Procedure Summary

I planned to follow this procedure to make the end float measurement. But as you will see, I had to deviate from it.

  1. Remove all oil, grease, dirt, schmutz from thrust washers, crankshaft journal thrust washer bosses and the rear bosses on the inside and outside of the engine block.
  2. Apply a light coat of engine assembly lube to the inside surface of front and rear main bearings.
  3. Install the inside thrust washer.
  4. Install the crankshaft.
  5. Install the front main bearing carrier.
  6. Install the rear thrust washer.
  7. Install the flywheel.
  8. Install a dial gauge indicator.
  9. Measure the end float.
  10. Change the outside thrust washer, if necessary, to get to 0.10 mm of end float.

If the end float is not correct, I can remove the flywheel and replace the outside thrust washer with one that will get me close to the target of 0.10 mm (0.0039 inch). But, due to uncertainty and doubt about the correctness of my initial measurements, I ended up removing and installing the crankshaft multiple times. That wasn’t what I originally planned to do, but as you will see later, I needed to deviate from the original work plan to be sure I had set the end float correctly.

Measure Thrust Washers

I bought three new thrust washers of different thickness so I can adjust the end float should the original washers not get me close to 0.10 mm. BMW supplies four different size “classes” of washers, sometimes referred to as “Red”, “Blue”, “Green” and “Yellow”, as shown in the table below. I bought a Red, Blue and Green thrust washer.

BMW Thrust Washers Sizes and "Colors"

There is a partial part number stamped on the back of the thrust washer so I can identify which color range it belongs to. But, there is a range of allowable thickness for each color so I measure the thickness of the original and new thrust washers as I describe later.

I use a micrometer that measures to 0.0001 inches–as in 1 ten-thousandth of an inch–to measure the thickness of the inside and outside thrust washers. I measured each washer at 12 locations around the face of the washer so I can determine the thickest part of the washer.

Mistake #1 – How To Measure The Correct Thrust Washer Thickness

I discovered later that the important measurement is the maximum thickness of the washer, not the average thickness.The thickest section of the washer determines the amount of end float the washer takes up. When I first did this work, I mistakenly used the average value and did not get the end float result I wanted when I installed a new thrust washer. It took some thinking to realize my mistake. I am used to averaging measurements to get a good approximation, but that’s not correct for this measurement.

Measure Original Thrust Washer Thickness

Before I start measuring the original thrust washers, I make an index mark in one of the four white segments on the front face of the washer. Then I measure around the circumference in a counter-clockwise direction from the mark. I make all my thrust washer measurements exactly this way so I can quickly determine where the thickest section of each washer is located. Why that matters will become clear later.

Measuring Thrust Washer Thickness with Precision Micrometer

Measuring Thrust Washer Thickness with Precision Micrometer

Thrust Washer Thickness Measurement Points

Thrust Washer Thickness Measurement Points

The table below shows my measurements for the two original thrust washers. The measurement at location #1 is on the first entry followed, of course, by the measurement at each location number in turn.

Original Thrust Washer Measurements

At the top of the spreadsheet, above the measurements, I record the micrometer “Base” which is the zero length of the micrometer. Since this is a 0-1 inch micrometer, the value is 0.0000. The “@ 0.0000” is what the micrometer shows when set to zero, which in this case is exactly zero. The “Temp” is the temperature at which the measurements were made, which should be at room temperature (68-70 F).

For each measurement I took, I add the “Base” and subtract the “@ 0.0000” value to get the result shown in the table. But, since this is a 0-1 inch micrometer and the zero reading is exactly zero, there are no corrections needed to my raw measurements.

Underneath the list of 12 measurements I computed some metrics: The “Largest” is the thickest measurement; the “Smallest” is the thinnest measurement; the “Range” is the difference between the Largest and Smallest measurement; and, the “Ave” is the average thickness. The most important value is the “Largest” as that is how much the thrust washer will affect the crankshaft end float.

NOTE:
The maximum variation of thickness of the original thrust washers is 0.0005 inches, or one-half thousandth of an inch.

The inside thrust washer is marked with a partial part # that corresponds to the Blue size category and the outside has the partial part # for the Green category. The range of thickness I measure falls within the minimum-maximum thickness for the color categories which confirms the partial part # markings are correct.

I mark the thickest measurement I found on the back of each washer with a Sharpie to make it easy to identify them later.

Original Outside Thrust Washer Back with Partial Part # & Maximum Thickness

Original Outside Thrust Washer Back with Partial Part # & Maximum Thickness

Original Inside Thrust Washer Back with Partial Part # & Maximum Thickness

Original Inside Thrust Washer Back with Partial Part # & Maximum Thickness

Measure New Thrust Washer Thickness

I measure the new thrust washers using the same technique. The table below shows what I found.

New Thrust Washer Measurements

New Thrust Washer Measurements

Note that the “Range” for the new Red and Blue thrust washers is on the order of 0.025 mm (0.001 inch) which is about one-half the allowed thickness range for each of those colors. The original washers, a Blue and a Green, had a range of thickness on the order of 0.013 mm (0.0005 inch) or about half the variation in thickness as the new ones. I am a bit surprised at how much the variation in thickness is for the new Red and Blue thrust washers.

Prepare The Engine

What is not mentioned in any of the manuals is that your measurements MUST be done on a dry engine. That means no oil, dirt, grit, or schmutz of any kind on the crankshaft main journals, thrust washer contact surfaces and the thrust washers. That said, a small amount of engine assembly lube is applied ONLY to the inside main bearings NOT to the crankshaft main journals before installing the crankshaft. The assembly lube protects the journals and bearings on the first engine start, but should not be so much lube that it gets scrapped off the main bearings when installing the crankshaft and gets transferred to the face of the thrust washers or the front main bearing journal face when the crankshaft and the front bearing carrier are installed.

Clean Thrust Washer Contact Surfaces

I clean the crankshaft journals and crankshaft thrust washer bosses with disposable shop towels sprayed with a bit of brake cleaner. I got quite a bit of gunk off them.

Clean The Front Crankshaft Thrust Washer Boss

Clean The Front Crankshaft Thrust Washer Boss

Clean The Rear Crankshaft Thrust Washer Boss

Clean The Rear Crankshaft Thrust Washer Boss

Nice Clean Journal Boss

Nice Clean Journal Boss

What I Got Off The Rear Crankshaft Thrust Washer Boss

What I Got Off The Rear Crankshaft Thrust Washer Boss

I use alcohol wipes to clean the front and back faces of the thrust washers and the engine block inside and outside thrust washer bosses. Since the inside thrust washer is captured by the crankshaft, I want to be sure I put the thinnest color class of washer on the inside of the engine. Then I can adjust the end float by changing the outside washer which is easy to do since all I have to do is remove the flywheel to change the washer.

Clean The Rear Bearing Inside Thrust Washer Boss

Nice Clean Rear Bearing Inside Thrust Washer Boss

Clean Rear Bearing Outside Thrust Washer Boss

Nice Clean Rear Bearing Outside Thrust Washer Boss

Original Rear Thrust Washer Clean and Dry

Original Rear Thrust Washer Clean and Dry

Apply Engine Assembly Lube To Main Bearings

I put a small amount of engine assembly lube on the inside surface of the rear main bearing and the front main bearing inside the front bearing carrier. It should be a thin sheen with no thick patches of lube. I don’t want a lot of assembly lube on the inside of the bearings since I don’t want any of it get on the thrust washers or the crankshaft thrust washer bosses when I install the crankshaft. I don’t put any on the crankshaft journals as it will get scraped off onto the edge of the thrust washers. Any assembly lube on the thrust washers or the thrust washer bosses will affect the end float measurement. How do I know that?

Mistake #2 – Putting Assembly Lube On The Crankshaft Journal

The picture below shows what I did wrong the first time I installed the crankshaft. I put assembly lube on the main journals instead on the inside of the main bearings.

Permatex Ultra Slick Engine Assembly Lube

Permatex Ultra Slick Engine Assembly Lube DOES NOT GO ON THE CRANKSHAFT JOURNAL

When I installed the crankshaft, assembly lube got scrapped off the crankshaft journals and was transferred to the thrust washers and the bearing carrier thrust washer boss. That invalidated the end float measurement.

I got 0.046 mm (0.0018 inches) of end float which is so far from the lowest value that I knew I had assembly lube on the thrust washer, but I didn’t know why until a long time airhead mechanic told me the correct place to apply the thin layer of assembly lube is on the inside of the main bearings, not on the main bearing journals. Based on this mistake, I had to remove the crankshaft, clean everything up, and start all over again.

Here is a short video of how getting assembly lube on the face of the thrust washer can invalidate your end play measurement by quite a lot.

CLICK TO GO TO VIDEO: Invalid End Float Measurement From Getting Assembly Lube on Thrust Washer Face

CLICK TO GO TO VIDEO: Invalid End Float Measurement From Getting Assembly Lube on Thrust Washer Face

Install The Crankshaft

Before I install the crankshaft, I put the smallest thrust washer class–in my case the original Blue class washer–on the pins in the rear of the engine block. I verify that there is no engine assembly lube, oil or grit on the faces of the washer or the inside thrust washer boss.

Inside Thrust Washer Mounts on Pins In The Rear of The Engine Block-The Boss MUST BE Clean & Dry

Inside Thrust Washer Mounts on Pins In The Rear of The Engine Block-The Boss MUST BE Clean & Dry

Original Inside Thrust Washer

Original Inside Thrust Washer

Thinnest Thrust Washer Mounted On Pins Inside The Engine Block

Thinnest Color Class Thrust Washer Mounted On Pins Inside The Engine Block

Next, I turn the engine around on my workbench so the rear of the engine is on the bench with the bell housing resting on two 2x4s, with the front of the engine block facing up. The 2x4s keep the engine block level and stable on the workbench. It is easier to heat the engine block and install the crankshaft, and since gravity is my friend in this orientation, the inside thrust washer is not prone to coming off its pins while I work.

Engine On The Rear Using 2x4 Support Under Bell Housing Makes It Easier to Heat The Case and Install The Crankshaft

Engine On The Rear Using 2×4 Support Under Bell Housing Makes It Easier to Heat The Case and Install The Crankshaft

I carefully slide the crankshaft into the block through the front bearing carrier hole. I tilt it a bit to the side to slide the rear counterweight through the hole and then rotate it 90 degrees to get the front counterweight through the hole. I hold the crankshaft as vertical as I can as I guide it into the rear main bearing so I don’t scrape assembly lube off the inside of the rear bearing.

Here is a short video on installing the crankshaft.

CLICK TO GO TO VIDEO: Install Crankshaft

CLICK TO GO TO VIDEO: Install The Crankshaft

Checking for Assembly Lube on Thrust Washer Face

One way to check if assembly lube has gotten on the face of the inside thrust washer is to pull the crank forward a small amount and look for lube on the washer face. I found even with a flash light, it wasn’t easy to see the full face of the thrust washer. And, that lead me to make another mistake.

Mistake #3 – Potential Transfer of Assembly Lube To Thrust Washer

If you pull the crankshaft too far forward when you check for any lube on the thrust washer face, as I did as shown in the picture below, you can scrape assembly lube that transferred to the crank journal from the main bearing onto the face of the washer when you let the crankshaft back down. That will invalidate your end float measurements. I got lucky this time.

If You Pull The Crank This Far, You Likely Get Assembly Lube On The Face of The Thrust Washer

If You Pull The Crank This Far, You Will Likely Get Assembly Lube On The Face of The Thrust Washer When You Push It Back In

After I thought about this, I decided to use a piece of white paper to check the front face of the inside thrust washer for any assembly lube transfer. I lift the crankshaft off the face of the thrust washer just enough so I can slide the paper between the face of the crankshaft and the thrust washer from the right side cylinder hole. I let the crank back down gently and rotate it a half revolution to the right and then back and a half revolution to the left. I remove the paper and check it to see if there are any sign of red assembly lube. There is none.

Checking For Red Assembly Lube On Thrust Washer Face

Checking For Red Assembly Lube On Thrust Washer Face Using Piece of White Paper Between The Thrust Washer and Crankshaft Face

Install Front Main Bearing Carrier

After I put a very thin coat of assembly lube on the inside of the front main bearing in the front bearing carrier, I put the bearing carrier into the freezer for several hours to cool it down. I want the front bearing carrier to “drop” in around the front crankshaft journal when I install it.

I need to heat the engine block around the bearing carrier to 250 F. I use two MAP-Pro gas torches to heat each side of the block. These torches deliver a lot of heat at a higher temperature than propane torches and I have a lot of aluminum to heat quickly.

Two MAP-Pro Torches Are Required To Heat Engine Block to 250 F

Two MAP-Pro Torches Are Required To Heat Engine Block to 250 F

Mistake #4 – How NOT To Heat The Engine Block

I learned that you do NOT want to heat the front face of the block around the crankshaft as that heats up the crankshaft. If the crankshaft gets too hot, the front bearing journal expands enough that it will interfere with the front main bearing and you will not be able to slip the front bearing carrier over the front main journal.

I did this incorrectly the first time heating the face of the engine block and with the block sitting on the oil pan which adds risk of the inside thrust washer coming off the pins. Since the crankshaft front main journal got too hot, I couldn’t get the front main bearing carrier to slide over the crankshaft front main journal. Using my non-contact infrared thermometer I estimated the crankshaft at a temperature of 160 F.

After I learned the proper heating technique (shown in the pictures below), I found the crankshaft temperature was only about  110 F when I was ready to install the front bearing carrier. Keeping the crankshaft 50 F cooler was enough to let the front bearing carrier slide over the front main journal with ease.

Here is a short video of the how NOT to heat the engine block around the front main bearing carrier.

CLICK TO GO TO VIDEO: How NOT To Heat The Engine Block!!!

CLICK TO GO TO VIDEO: How NOT To Heat The Engine Block!!!

I do have to heat underneath the bearing carrier on the front face of the engine block. When I heat that area I point the flame of the torch away from the crankshaft so it doesn’t directly heat it.

Here is a short video showing the correct way to heat the engine block around the front main bearing carrier.

CLICK TO GO TO VIDEO: How To Heat The Engine Block

CLICK TO GO TO VIDEO: How To Heat The Engine Block

The pictures below show where I apply the torches to the engine block for quickest heating of the block with minimum heating of the crankshaft.

Where To Heat Engine Block-Keep Flame Away From Crankshaft

Where To Heat Engine Block-Keep Flame Away From Crankshaft

Where To Heat Engine Block-Keep Flame Away From Crankshaft

Where To Heat Engine Block-Keep Flame Away From Crankshaft

Where To Heat Engine Block-Keep Flame Away From Crankshaft

Where To Heat Engine Block-Keep Flame Away From Crankshaft

Where To Heat Engine Block-Note Flame Points Away From Crankshaft

Where To Heat Engine Block-Note Flame Points Away From Crankshaft

Where To Heat Engine Block

Where To Heat Engine Block

NOTE:
I took the pictures above after I had installed the front bearing carrier. Sometimes I decide to take pictures after the fact :-).

After heating the block for several minutes I measure the temperature of the inside edge of the bearing carrier hole in the engine block with a non-contact infra-red thermometer. It is not too accurate due to the high reflectivity of the aluminum. When I get readings from 210-280 F, depending on where I make the measurement, I take the bearing carrier out of the freezer. I orient it so it is aligned with the studs and then push it down while centering the crankshaft with the bearing in the bearing carrier. As the bearing carrier starts to slide over the crankshaft journal I quickly push the carrier all the way down until it butts up against the face of the engine block. It only takes a couple seconds for the bearing carrier to heat up so I don’t waste any time pushing it down against the face of the engine block as I don’t want it to bind up on the crankshaft front main journal.

Here is a short video of installing the front main bearing carrier. When done correctly, the front main bearing carrier slides easily over the crankshaft front main journal.

CLICK TO GO TO VIDEO: Install Front Bearing Carrier

CLICK TO GO TO VIDEO: Install Front Bearing Carrier

WARNING:
If the front bearing carrier binds on the crankshaft front main journal as you are installing it, STOP. Do not force it or get a hammer to pound it home.

You need to reinstall the front bearing carrier puller, reheat the case to 250 F, and extract the bearing carrier.  At this point, I would start from the beginning again: Pull the crankshaft out; Clean the main journals, the main bearings, the thrust washers and the thrust washer bosses; lightly apply engine assembly lube to the bearings again; Freeze the front bearing carrier for a couple hours; Reheat the engine block and, attempt to install the front bearing carrier again. You gain nothing by rushing or taking short cuts here.

I finger tighten the three nuts and wave washers on the three short studs to secure the bearing carrier to the front of the engine block and let everything cool down to room temperature. Then I torque the bearing carrier nuts to 17 Ft-Lbs.

Torque Front Bearing Retainer Nuts to 17 Ft-Lbs

Torque Front Bearing Retainer Nuts to 17 Ft-Lbs

DANGER
Anytime the flywheel is removed YOU MUST install the front bearing carrier puller with the puller bolt snug against the crankshaft nose so the inside thrust washer does not come off its pins. 

Before I move the engine block to rest it on the oil pan, I install the Cycle Works bearing carrier puller tool onto the bearing carrier. I hand tighten the puller bolt so the crankshaft is pushed firmly to the back to capture the inside thrust washer so it won’t come off the pins. Then I move the engine block so it is sitting on the oil pan so I can install the flywheel.

Cycle Works Bearing Retainer Mounted To Push Crank Backward Capturing Inside Thrust Washer

Cycle Works Bearing Carrier Tool Mounted To Push Crank Backward To Capture The Inside Thrust Washer Against The Engine Block

Install The Flywheel

Before I install the rear thrust washer that butts up against the flywheel, I make sure it’s the correct one, in this case, the original thicker Green class washer. I use an alcohol wipe to clean the thrust washer boss on the rear of the engine block and inspect the faces of the thrust washer to be sure they are clean and oil free. Then I install the washer on the two pins on the outside of the engine block.

Original Outside Thrust Washer

Original Outside Thrust Washer

Clean Rear Bearing Thrust Washer Boss

Clean Rear Bearing Thrust Washer Boss

Rear Thrust Washer Clean and Dry

Rear Thrust Washer Clean and Dry

I install a new o-ring into the groove in the flywheel guide ring and put some engine oil on the o-ring to lubricate it. Then I insert the guide ring into the hole in the flywheel. I heat the outside edge of the guide ring with a propane torch and then install the guide ring with the flywheel attached to it onto the end of the crankshaft being sure the flywheel bolt hole with the alignment mark matches up with the alignment mark next to the bolt hole on the crankshaft. I install three old flywheel bolts and torque them to 17 Ft-Lbs.

Flywheel Mounted with Three Bolts Torqued to 17 Ft-Lbs

Flywheel Mounted with Three Bolts Torqued to 17 Ft-Lbs

With the flywheel installed, I remove the Cycle Works front bearing carrier tool.

Here is a short video showing how I install the flywheel.

CLICK TO GO TO VIDEO: Install Flywheel

CLICK TO GO TO VIDEO: Install Flywheel

Install The Dial Indicator

I install the dial indicator with the 0.0005 inch dial to the front of the engine and position the nose of the indicator to touch the front face of the timing sprocket journal perpendicular to its face.

Attaching Dial Indicator to Engine Block

Attaching Dial Indicator to Engine Block

Dial Indicator Positioned on Front of Timing Chain Journal

Dial Indicator Positioned on Front of Timing Chain Journal

Take The First End Float Measurement

I put my hands on the crankshaft through the cylinder holes so I can push the crankshaft all the way back and adjust the dial indicator zero to align with the needle. Then I pull the crankshaft forward. I repeat the push back and pull forward several times to be sure I get consistent measurements.

Where I Push The Crankshaft Backward And Pull It Forward

Where I Push The Crankshaft Backward And Pull It Forward

I measure between 0.0003 and 0.00032 inches of end float. This is at the low end of the range of allowable end float. The question is, do I believe my measurements?

Dial Indicator Zeroed for End Float Measurement with Original Thrust Washers

Dial Indicator Zeroed for End Float Measurement with Original Thrust Washers

Crankshaft End Float Measurement with Original Thrust Washers-Too Small

Crankshaft End Float Measurement with Original Thrust Washers-Too Small

Here is a short video of taking the end float measurement with the original thrust washers. Although I wasn’t sure at the time, this measurement turned out to be correct as I did not get assemble lube on the face of the thrust washer as explained later.

CLICK TO GO TO VIDEO: Install Dial Indicator, Measure End Float

CLICK TO GO TO VIDEO: Install Dial Indicator, Measure End Float

Making Sure I Believe My Measurements

As this is the first time I’ve done this work, I am not positive I avoided getting assembly lube on the original thrust washer faces. So I decide to remove the crankshaft, clean all the thrust washer surfaces and the bosses, reinstall the crankshaft and take the measurements again with the original thrust washers but with dry main bearings to see if I get the same end float measurement.

Remember before you remove the flywheel:

DANGER
Anytime you are going to remove the flywheel YOU MUST install the front bearing carrier puller with the puller bolt snug against the crankshaft nose so the inside thrust washer does not come off its pins.

Of course, this means I will have to remove the crankshaft afterwards so I can apply engine assembly lube to the main bearings and put it all back together again. But I believe being this cautious will ensure that I know I am getting correct end float measurements and I can see if I got an accurate measurement when I put a light coat of assembly lube on the main bearings. The extra work is all part of my education :-).

Cycle Works Guide Ring Removal Tool

When I remove the flywheel, the guide ring stays on the crankshaft. I acquired the Cycle Works tool for removing the guide ring from the crankshaft. This is an opportunity to try it out.

NOTE:
I’m not sure this tool is still available. Below, I show another technique for removing the guide ring that does not require this tool. It works and takes less time.

Cycle Works Guide Ring Removal Tool

Cycle Works Guide Ring Removal Tool-Note The Three Legs On The Rear Face of The Large Washer at Top Right

It consists of a washer with three threaded legs, three long 6 mm puller bolts, and a nut that has been machined to act like an “E-clip”. The threaded legs are welded to the rear face of the large washer and fit inside the crankshaft holes to protect the crankshaft bolt hole threads from the long puller bolts. The flat side of the large washer faces you when it’s installed on the face of the guide ring.

Outside Face Of Large Washer

Outside Face Of Large Washer

Large Washer Installed-Feet Go Inside Crankshaft Bolt Holes

Large Washer Installed-Feet Go Inside Crankshaft Bolt Holes

The machined nut slides over the nipple of the guide ring sleeve on top of the large washer. I use needle nose pliers to slide the nut into the groove in the guide ring nipple.

Nut Modified To Act As An "E-cip"

Nut Modified To Act As An “E-clip”

"E-clip" Installed on Groove of Guide Ring Nipple

“E-clip” Installed on Groove of Guide Ring Nipple

Snug "E-clip" Onto Nipple

Snug “E-clip” Onto Nipple Using Needle Nose Pliers

NOTE:
I had to grind off some of the corners of the nut to get enough clearance for the three long bolts to get past it.

Then I screw in the three long bolts all the way in until they bottom out inside the crankshaft bolt holes. I tighten them in an alternating pattern to pull the guide ring off the crankshaft.

Guide Ring Removed

Guide Ring Removed

Guide Ring Removed

Guide Ring Removed

Alternate Method For Removing Flywheel Guide Ring

Later I learned that you can remove the guide ring by heating around the crankshaft bolt holes of the guide ring then wiggle it off the flywheel with a pair of channel lock pliers. This method worked well and takes less time than installing the Cycle Works guide ring puller. That said, if the guide ring is really stuck, the Cycle Works puller will get it off the crankshaft nose.

Heating Guide Ring To Remove It

Heating Guide Ring To Remove It

Guide Ring Removed By Wiggling It Off With Vice Grip Pliers

Guide Ring Removed By Wiggling It Off With Vice Grip Pliers

Remove And Install The Crankshaft – Again

I remove the crankshaft as described here.

Of course, I don’t need to remove the camshaft again as I have not reinstalled it yet.

After I remove the crankshaft I clean the thrust washers, the crankshaft and engine block thrust washer bosses and the inside of the bearings to remove all the engine assembly lube. Then I reinstall the inside thrust washer, crankshaft, front bearing carrier, the outside thrust washer and the flywheel as described above. But this time I measure the end float with dry main bearings.

End Float with Lightly Lubed Main Bearings vs. Dry Bearings

With the original thrust washers installed, I make the end float measurement again. I got exactly the same end float of 0.0030-0.0032 inches. On one hand that’s encouraging as I didn’t get assembly lube on the thrust washers, but on the other hand this end float is below, or just at, the minimum allowed end float. So I will increase the end float.

End Float-Original Thrust Washers, Lubed vs. Dry

End Float-Original Thrust Washers, Lubed vs. Dry

Adjusting End Float To Meet The Target of 0.10 mm

I computed the thrust washer thickness I need to hit my target of 0.10 mm (0.0039 inches). I need to replace the original outside Green class washer with my new Blue class washer. Based on my calculations, to achieve the desired end float, I need a thrust washer that has a maximum thickness of 2.564 mm (0.1010 inches).

The new Blue washer I bought has a maximum thickness of 2.573 mm (0.1013 inches) which is 0.009 mm (0.0004 inches) thicker than my target. Since I carefully took my measurements starting at the color mark and going counter-clockwise, I know where the high spot is on the thrust washer. I mark the area of the high spot on the front face of the washer with a Sharpie. I use wet 1000 grit wet/dry paper on a glass plate and carefully sand the area of the high spot on the back side of the thrust washer to reduce it to 2.563 mm (0.1009 inches). Yes, I’m ended up a bit less than my target thickness.

Carefully Reducing The High Spot On Thrust Washer

Carefully Reducing The High Spot On Thrust Washer

NOTE:
The specifications for the thrust washers allows 0.02 mm loss in thickness. I removed less than half of that.

I use a figure eight pattern while sanding the back of the thrust washer. I sand the figure eight pattern 10 times and then take several measurements along the length of the high spot. I proceed in small increments of sanding until the high spot is within my target range. As I work, the area to sand gets shorter so I limit my sanding to only the remaining high part of the washer. It took me about 20 minutes of careful work to get the maximum thickness I wanted.

I clean the washer with alcohol wipes and then I remeasure the thrust washer thickness at all 12 locations. The table below shows I was successful removing only the high spot which reduced the range of the thrust washer thickness so it is close to the range I found for the original thrust washers. I use a Sharpie to mark the back of the adjusted Blue class thrust washer with its maximum thickness of 2.563 mm.

New Blue Thrust Washer Thickness vs Adjusted Thickness

New Blue Thrust Washer Thickness vs Adjusted Thickness

DANGER
Before you remove the flywheel to replace the outside thrust washer, YOU MUST install the front bearing carrier puller with the puller bolt snug against the crankshaft nose so the inside thrust washer does not come off its pins.

I once again remove the flywheel and the guide ring, this time using the heating method and channel lock pliers to wiggle the guide ring off the crankshaft nose. I wipe the rear thrust washer boss with an alcohol pad and then I install the clean, dry, adjusted Blue class thrust washer. I install the flywheel again and torque three bolts to 17 Ft-Lbs.

Installing New Blue Adjusted Thrust Washer On Outside Pins

Installing New Blue Adjusted Thrust Washer On Outside Pins

I remove the front bearing carrier puller tool and mount the dial indicator to take end float measurements. I am right at 0.101 mm (0.004 inches) so this thrust washer adjustment puts the end float at the optimum value.

Adjusted Outside Blue Thrust Washer End Float Measurement

Adjusted Outside Blue Thrust Washer End Float Measurement

Adjusted Outside Blue Thrust Washer End Float Measurement

Adjusted Outside Blue Thrust Washer End Float Measurement

Here is a short video of taking what turned out to be the final end float measurement with the adjusted thrust washer.

CLICK TO GO TO VIDEO: Final End Float Measurement

CLICK TO GO TO VIDEO: Final End Float Measurement

Belt and Suspenders End Float Measurement Check

I kept one other set of calculations to prove my end float measurements are correct. This set of calculations computes the “free” float of the crankshaft without thrust washers. Each time I take a measurement of the end float, the sum of the thrust washers and end float should equal the same crankshaft “free” float value as shown in the table below. The maximum difference in computed “free” float I had was one ten-thousandth of an inch (0.0001 inches) which is not an issue. If I saw several ten-thousandths difference, I would suspect assembly lube was transferred to the thrust washers, or I made some other kind of error when I took the measurement.

Crankshaft "Free" Float Calculation

Crankshaft “Free” Float Calculation (Inches)

Remove and Install The Crankshaft – Final Time

Now, I need to remove the flywheel and crankshaft again since I have to put engine assembly lube on the main bearings and then reinstall the inside thrust washer, crankshaft, front bearing carrier, outside thrust washer and flywheel.

But, before I install the flywheel, I oil the face of the inside thrust washer. I have the  front bearing carrier puller installed with the puller bolt pushing the crankshaft back since the flywheel is not installed yet. I loosen the puller bolt a turn and carefully pull the crankshaft forward to open up a gap between the inner thrust washer and the face of the crank journal. I squirt engine oil into the gap between the thrust washer face and the crankshaft journal. I rotate the crankshaft carefully and squirt more oil into the gap so I fully lube the face of the inner thrust washer. Then I tighten up the puller bolt and install the flywheel.

Oiling Face Of Inside Thrust Washer

Here is a short video showing how I lube the inside thrust washer.

CLICK TO GO TO VIDEO: Oil The Face Of The Inside Thrust Washer

CLICK TO GO TO VIDEO: Oil The Face Of The Inside Thrust Washer

Install Camshaft

The flywheel has to be off to install the camshaft since the oil pump is installed on the back end of the camshaft and the oil pump is behind the flywheel. However, if the flywheel is not installed, then the crankshaft can move forward and that could allow the inside thrust washer to come off the pins. But, I can’t install the camshaft if I have the front bearing carrier puller installed because the camshaft timing gear interferes with the puller tool. That means I end up with having the flywheel off the crankshaft and the crankshaft is free to move forward potentially dislodging the inside thrust washer.

Therefore, after I oil the inside thrust washer as explained above, I hand tighten the puller bolt on the front bearing carrier removal tool. Then I put assembly lube inside the hole at the rear of the engine block that the rear camshaft bearing journal slides into and on the inside surface of the camshaft front bearing carrier hole.

Engine Assembly Lube Inside Rear Camshaft Bearing Journal Hole

Engine Assembly Lube Inside Rear Camshaft Bearing Journal Hole

Engine Assembly Lube Inside Rear Camshaft Journal Hole In Engine Block

Engine Assembly Lube Inside Front Camshaft Bearing Carrier Hole In Engine Block

Then I reorient the engine so the rear of the block is resting on the workbench with the two 2x4s under the bell housing to support and stabilize the block. In this orientation, gravity is my friend pushing the crankshaft down against the inside thrust washer.

Engine Block Orientation To Install Camshaft

I put assembly lube on the camshaft rear journal and I squirt some oil into the two holes in the camshaft front bearing carrier to lubricate the front bearing. Then I freeze the camshaft for several hours to shrink the rear journal and the front bearing carrier.

Engine Assembly Lube On Frozen Camshaft Rear Bearing Journal

Engine Assembly Lube On Frozen Camshaft Rear Bearing Journal

Camshaft Front Bearing Carrier Oil Hole-There Are Two of Them And I Put Oil In Both

Camshaft Front Bearing Carrier Oil Hole-There Are Two of Them And I Put Oil In Both

I put the camshaft into the engine block and align the rear journal with the hole in the rear of the engine block by looking through the left cylinder hole. I orient the flange on the front bearing carrier so it doesn’t interfere with the crankshaft front bearing carrier and push the camshaft all the way down until the front bearing carrier is flush with the front of the engine block.

Camshaft Installed

I insert the two bolts that secure the camshaft front bearing carrier to the block and tighten them finger tight. I wait for the camshaft to warm back up to room temperature and then torque the two bolts to 12 Ft-lbs. Since that’s a low value, I use my INCH-pound wrench set to 144 INCH-Lbs to torque the bolts.

After I torque the camshaft bolts, I install the crankshaft front bearing carrier puller tool with the puller bolt finger tight and then reorient the engine block so its sitting on the oil pan.

Here is a short video of installing the camshaft.

Install Oil  Pump

I show how to do that here:

Final Thoughts

If I had done the crankshaft installation and end float measurement multiple times, I’d be more comfortable lightly lubing the main bearings with engine assembly lube and taking the end float measurements with confidence that I got the correct end float measurement. Since I’m a novice at this work, I decided to invest the extra time to remove and then install the crankshaft dry so I could make the end float measurements without worry I had gotten assembly lube on the thrust washers and/or thrust washer bosses.Then I once again removed and installed the crankshaft after putting assembly lube on the main bearings. The extra work makes up for my lack of experience. I am comfortable that my end float measurement of 0.101 mm (0.004 inches) is accurate.

As they say, “Practice Makes Perfect”.  I only have 100 more engines to go before I come close to achieving that lofty goal. 🙂

Revisions

2020-01-04  Reorganize for better flow and clarity.

2 thoughts on “11 BMW 1983 R100RS Install Crankshaft, Adjust End Float, Install Camshaft

  1. Excellent work Brook. Last winter I rebuilt my 94 r100gs transmission using your excellent tutorial. The transmission has been performing flawlessly. There wasn’t even thin fuzz on the magnetic drain plug at the 3000 mile gear oil change. After the first reading of your new crankshaft end play measurement article I wonder how BMW mass produced these engines. Assembly doesn’t appear to be a robust, error tolerant, affair. Again: excellent work and thank you. Cheers, Bill

    • Hi Bill,

      Thank you for the kind words. This work is as interesting/dangerous/detailed as the transmission work I posted. So it’s not for everyone. I spent weeks chipping away at this and took time to think about what I did, and when end play didn’t change as I expected, to take it all apart and start fresh. If you don’t have that kind of patience, this is not work you should do.

      I too wonder how they got end float correct in minimal time. I suspect they got precise crankshaft measurements after machining and heat treating where it mattered and then pulled the correct color class thrust washers for that “class” of crankshaft so the end float would be within their published specifications (which are too large according to more than one long time airhead mechanic I spoke with).

      That said, I’ve heard from one long time mechanic that it was not uncommon for customer bikes with the transmission problems that I mention in the write-up to require resetting the factory end play to fix them.

      All the best on your next project Bill.

      Best.
      Brook.

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