11 BMW 1983 R100RS Remove Timing Chain, Crankshaft Nose Bearing & Sprocket

Due to the 83,000+ miles on the bike, I’m going to replace the following parts:

  • Timing Chain
  • Timing Chain Tensioner & Slide Rail
  • Crankshaft Nose Bearing
  • Crankshaft Timing Sprocket
  • Front Main Seal
  • Inner Timing Cover Gasket & “Doughnut” Gaskets

This write-up shows how to remove these parts. A separate write-up will show how to install the new parts.

I’m going to open the oil high pressure relief valve and inspect it as well.

Since this model has the electronic tachometer and electronic ignition with the “bean can” ignition sensor, there is no camshaft seal. The bean can use an o-ring and I’ll replace that when I install electrical components under the front engine cover which I document in a separate write-up.

I already removed the electrical components and wiring from inside the front engine cover. You can read about how I removed the electrical components here.

Electrical Components Inside Front Engine Cover: Diode Board, Alternator, Ignition Sensor-Labeled

Electrical Components Inside Front Engine Cover: Diode Board, Alternator, Ignition Sensor

Electrical Components and Wiring Removed From Inner Timing Cover

Electrical Components and Wiring Removed From Inner Timing Cover

These have to be removed so I can remove the inner timing cover to get access to the timing chain, crankshaft nose bearing and timing chain sprocket, and the oil high pressure relief valve.

Tools

I use tools from Cycle Works to remove the crankshaft nose bearing and timing sprocket and to install the new parts. Cycle Works sells three levels of tools, Stage I, Stage II and Stage III.

The Stage I kit lets you remove/install the crankshaft nose bearing and timing sprocket, but does not include a tool to remove the inner timing cover (shown as XXed out in the picture below). I show how to remove the inner timing cover without a tool in this write-up.

Cycle Works Stage I Tools Showing Stage II Tools Not Included [SOURCE: www.cycleworks.net]

Cycle Works Stage I Tools Showing Stage II Tools Not Included [SOURCE: www.cycleworks.net]

The Stage II kit includes a tool to remove/install the front main bearing carrier that can also be used to remove/install the inner timing cover.

Cycle Works Stage II Tools [SOURCE: www.cycleworks.net]

Cycle Works Stage II Tools [SOURCE: www.cycleworks.net]

I purchased the Stage III kit which includes all the tools I need for this work along with the tools to remove the front and rear main bearings.

Cycle Works Stage III Tools [SOURCE: www.cycleworks.net]

Cycle Works Stage III Tools [SOURCE: www.cycleworks.net]

I also use MAP gas for heating parts to aid in disassembly.

MAP Gas to Heat Inner Timing Cover

MAP Gas to Heat Inner Timing Cover

Video

I shot a video summarizing this work.

Remove Ground Wire “Octopus”

There is an “octopus” of ground wires on this bike to ensure a solid ground for the diode board with the original rubber diode board mounts and the painted inner timing cover. I replaced the rubber mounts when I first got the bike and installed solid metal mounts. To remove all the legs of the octopus, I remove the top two mounts to free two of the grounds.

Ground Wire "Octopus"

Ground Wire “Octopus”

Removing Inner Timing Cover Ground Wire "Octopus"

Removing Inner Timing Cover Ground Wire “Octopus”

Nuts On Inside of Inner Timing Secure Diode Board Studs

Nuts On Inside of Inner Timing Secure Diode Board Studs

Diode Board Top Mount Removed

Diode Board Top Mount Removed

Remove Inner Timing Cover Bolts & Nuts

Before I get started, I wrap a couple layers of masking tape around the tapered nose of the crankshaft where the alternator rotor mounts. This is a precision machined surface and I want to protect it from getting dirty or dinged while I work.

Crankshaft Taper Is Precision Machined Surface

Crankshaft Taper Is Precision Machined Surface

Masking Tape To Protect Crankshaft Taper

Masking Tape To Protect Crankshaft Taper

The inner timing cover is secured to the engine block with nine Allan bolts and three Allan washers in the locations shown in the picture below.

Inner Timing Cover Fastener Locations & Types

Inner Timing Cover Fastener Locations & Types

I break them loose in a cross-wise pattern. Then I remove them and place each in a piece of cardboard with an outline of the timing cover, what call my “Bingo” card, so I make sure I get them all and each is placed in the location in the card corresponding to where they are in the inner timing cover.

Removing One of (9) Inner Timing Cover Allan Bolts

Removing One of (9) Inner Timing Cover Allan Bolts

Removing One of (3) Inner Timing Cover Allan Nuts

Removing One of (3) Inner Timing Cover Allan Nuts

Allan Nut Removed

Allan Nut Removed

Filling In the Inner Timing Cover Bolt/Nut "Bingo" Card

Filling In the Inner Timing Cover Bolt/Nut “Bingo” Card

NOTE:
The cardboard fastener holder is not really needed since all the bolts are the same size/length and you can’t accidentally install one of nuts incorrectly. That said, this is part of my “belt and suspenders” discipline when removing a lot of hardware particularly if it’s the first time I’ve removed that hardware. The cardboard fastener holder makes sure if there are any size/length differences in the fasteners, I don’t  have to figure that out when I reinstall the hardware. I learned this when I was working on vintage Triumph/BSA’s where they loved changing fastener hardware all the time. 🙂

Although they may not fall out when you remove the Allan nuts, there is a thick washer underneath each of them. Try to get the washers out before you remove the timing cover so you don’t lose any when the cover comes off.

Bingo Bolt Card Filled In with 3 Washers Under Allan Bolts Taped On

Bingo Bolt Card Filled In with 3 Washers Under Allan Bolts Taped On

Remove Inner Timing Cover Without Special Tools

You can usually remove the inner timing cover without the need for any special tools. The trick is to heat the cover around the crankshaft seal with a heat gun (if you want to save the seal and reuse it) or you can use a torch if you are going to replace it.

MAP Gas to Heat Inner Timing Cover

MAP Gas to Heat Inner Timing Cover

Heating Around Crankshaft Nose Bearing with Torch ONLY If You Plan To Replace The Main Crankshaft Seal, Otherwise Use A Heat Gun

Heating Around Crankshaft Nose Bearing with Torch ONLY If You Plan To Replace The Main Crankshaft Seal-Otherwise Use A Heat Gun

Wearing my welding gloves, I can wiggle and pull the inner timing cover off without much trouble. The front main crankshaft seal stays in the cover and I’ll remove it later. There are some casting marks on the inside of the cover.

Outside Surface of Inner Timing Cover

Outside Surface of Inner Timing Cover

Inside Surface of Inner Timing Cover

Inside Surface of Inner Timing Cover

Inner Timing Cover Casting Marks Below Crankshaft Seal

Inner Timing Cover Casting Marks Below Crankshaft Seal

OPTIONAL-Cycle Works Timing Cover Removal Tool

If you can’t get the cover off, you can use the Cycle Works Stage II or Stage III engine tools as both contain a metal plate you can use to pull the cover off. I used to use the plate to remove the timing covers which came off very easily. So this time I used heat and my hands and it came off just as easily with less time spent putting the tool together.

Nonetheless, here is how the tool goes together to remove the inner timing cover.  Besides the parts from Cycle Works, you need to use the three alternator stator cover bolts to hold the plate to the timing cover.

Cycle Works Tools To Pull Inner Timing Cover

Cycle Works Tools To Pull Inner Timing Cover

As shown in the picture above there is a large aluminum plate, a puller bolt, a steel puller nose, and a small Allan bolt. The three alternator stator housing bolts are shown underneath the large aluminum plate.

Cycle Works Puller Plate Detail

Cycle Works Puller Plate Detail

As shown above, one side of the aluminum plate has a slot cut to accept the face of the steel puller nose. The other side of the aluminum plate is different as shown below.

Cycle Works Puller Plate Detail

Cycle Works Puller Plate Detail

As shown below the steel puller nose fits into the grooved side of the aluminum plate with the nose sticking out the other side.

Cycle Works Puller Nose Inserted in Puller Plate

Cycle Works Puller Nose Inserted in Puller Plate

Cycle Works Puller Nose Inserted in Puller Plate

Cycle Works Puller Nose Inserted in Puller Plate

Before I install the tool, I thread the small Allan bolt into the nose of the crankshaft taper to protect it from the puller bolt. I install the large aluminum plate with the steel puller nose on the crankshaft nose and then thread the large puller bolt into the puller nose.  I tighten the puller bolt to pull the inner timing cover off.

IMPORTANT: Install Small Allan Bolt in Crankshaft Nose To Protect It From The Puller Bolt

IMPORTANT: Install Small Allan Bolt in Crankshaft Nose To Protect It From The Puller Bolt

Cycle Works Inner Timing Cover Tool Installed-Just Tighten The Puller Bolt

Cycle Works Inner Timing Cover Tool Installed-Just Tighten The Puller Bolt To Pull Off The Cover

Tour Of Inside Of The Inner Timing Cover

Now the inner timing cover is off I can access the parts underneath it.

Components Under The Inner Timing Cover

Components Under The Inner Timing Cover

In the picture above, the inner timing cover gasket is stuck to the engine block. And there are two “doughnut” gaskets around the top top two cover bolts. But, there is no oil where the doughnut gaskets are. If you think of the cover gasket as a shim with a certain thickness, then in order for the cover to bolt to engine block evenly and uniformly to give an oil tight seal, the top two bolts through the cover need shims of the same thickness. Hence, the two doughnut shims.

Location of Inner Timing Cover "Doughnut" Gaskets

Location of Inner Timing Cover “Doughnut” Gaskets

Inner Timing Cover "Doughnut" Gasket

Inner Timing Cover “Doughnut” Gasket

At the bottom is the large diameter camshaft timing sprocket. There is a punch mark at the 12:00 position. When the engine is at top-dead-center (TDC), this punch mark will be either in the 12:00 or 6:00 position.

Camshaft Sprocket with Timing Chain

Camshaft Sprocket with Timing Chain

Location of Camshaft Sprocket Punch Mark at TDC

Location of Camshaft Sprocket Punch Mark at TDC

The reason it could be at either position is because the camshaft rotates one-half turn for every turn of the crankshaft. For that to happen, the camshaft sprocket is larger than the crankshaft sprocket; it is twice the diameter and has twice as many teeth as the crankshaft sprocket.

The crankshaft sprocket is behind the crankshaft nose bearing.

Crankshaft Sprocket Is Behind Crankshaft Nose Bearing

Crankshaft Sprocket Is Behind Crankshaft Nose Bearing

The timing chain in the 1983 engines is a single row chain whereas the earlier engines used a dual row chain. The chain uses a master link, which is very convenient, while the earlier dual row chains were continuous so you had to use a bolt cutter to cut the chain to remove it. The single row chain has a chain tensioner on the right and a slider on the left.

Right Side Timing Chain Tensioner Detail

Right Side Timing Chain Tensioner Detail

Left Side Timing Chain Slider Detail

Left Side Timing Chain Slider Detail

Remove Timing Chain

The crankshaft rotates clockwise (direction of the red arrow in the picture below) when viewed from the front of the engine. Consequently, the master link fish clip is installed so “the fish swims down stream”; the head of the fish clip points in the direction the chain moves.

Master Link Fish Clip Orientation (Fish Swims Downstream)

Master Link Fish Clip Orientation (Fish Swims Downstream)

I use needle nose pliers to remove the fish clip from the master link. I use a small screw driver to push the master link pin out of the chain. You could use a paper clip. Then I pull the timing chain out.

Remove Timing Chain Fish Plate with Needle Nose Pliers

Remove Timing Chain Fish Plate with Needle Nose Pliers

Timing Chain Master Link Fish Clip and Fish Plate Removed

Timing Chain Master Link Fish Clip and Fish Plate Removed

Push Timing Chain Master Link Out with Small Screw Driver

Push Timing Chain Master Link Out with Small Screw Driver

Single Row Timing Chain Removed

Single Row Timing Chain Removed

Remove Chain Tensioner and Slider

The chain tensioner arm slips over a pin secured by a circlip. I use a screw driver to push the circlip out of it’s groove and remove the timing chain tensioner.

Timing Chain Tensioner Arm Circlip

Timing Chain Tensioner Arm Circlip

Timing Chain Tensioner Arm Circlip Removed

Timing Chain Tensioner Arm Circlip Removed

There is a indentation where the tensioner piston pushes on the arm. The piston and it’s spring pop out of the sleeve the fit in as soon as I remove the tensioner arm.

Timing Chain Tensioner Arm Detail

Timing Chain Tensioner Arm Detail

Timing Chain Tensioner Spring & Plunger Fit Inside Sleeve Behind Them

Timing Chain Tensioner Spring & Plunger Fit Inside Sleeve Behind Them

The slider is secured with a nut and a bolt. I remove them. There is a wave washer under the nut and bolt and also there is a thick flat washer under the slider bracket on the stud and on the bolt.

Remove Timing Chain Slider

Remove Timing Chain Slider

Timing Chain Slider Hardware Detail

Timing Chain Slider Hardware Detail

Timing Chain Slider Hardware Detail

Timing Chain Slider Hardware Detail

(2) Thick Flat Washers Are Under Timing Chain Slider

(2) Thick Flat Washers Are Under Timing Chain Slider

The side of the slider that faces me has markings on it. That side also has a rounded profile of the cast rubber. There are no markings on the back side of the slider.

Timing Chain Slider-Outward Facing Side Has Markings

Timing Chain Slider-Outward Facing Side Has Markings

Timing Chain Slider-Outward Facing Side Profile

Timing Chain Slider-Outward Facing Side Profile

Timing Chain Slider-Inward Facing Side Has No Markings

Timing Chain Slider-Inward Facing Side Has No Markings

Remove Crankshaft Nose Bearing & Timing Chain Sprocket

I’m ready to remove the crankshaft nose bearing and timing sprocket.

Ready To Remove Crankshaft Nose Sprocket & Timing Sprocket

Ready To Remove Crankshaft Nose Sprocket & Timing Sprocket

I use the Cycle Works tool to remove them.

Cycle Works Crankshaft Nose Bearing & Timing Sprocket Puller Tool

Cycle Works Crankshaft Nose Bearing & Timing Sprocket Puller Tool

In addition to the parts shown in the picture above, I have put a couple layers of masking tape in the crankshaft taper to protect it from scratches. And, I install the small Allan bolt into the threaded hole in the crankshaft nose to protect the nose from the puller bolt.

Cycle Works Crankshaft Nose Protects Nose From Damage

Cycle Works Crankshaft Nose Bolt Protects Nose From Damage-Masking Tape Protects Taper

The tool has a clam shell. Each half has a thick and thin shoulder. The thick shoulder goes up against the puller nose and the thin shoulder goes behind the crankshaft timing sprocket.

Clam Shell Half Showing Wide & Narrow Shoulders

Clam Shell Half Showing Wide (Left) & Narrow (Right) Shoulders

Puller Bolt Screws Into Puller Nose

Puller Bolt Screws Into Puller Nose

Puller Nose Fits Against Wide Shoulder of Clam Shell Halves

Puller Nose Fits Against Thick Shoulder of Clam Shell Halves

I put one half of the clam shell around the crankshaft sprocket and nose bearing being sure the thin ridge is behind the sprocket.

Clam Shell Half Narrow Shoulder Goes Behind Crankshaft Timing Sprocket

Clam Shell Half Narrow Shoulder Goes Behind Crankshaft Timing Sprocket

Clam Shell Half Narrow Shoulder Goes Behind Crankshaft Timing Sprocket

Clam Shell Half Narrow Shoulder Goes Behind Crankshaft Timing Sprocket

I insert the puller nose with the puller bolt partially threaded into it inside the clam shell half and install the second half so it’s behind the crankshaft sprocket and captures the puller body. Then I tighten the puller bolt until it’s snug at which point the clam shell halves will stay on the crankshaft sprocket.

Cycle Works Tool Assembled Around Crankshaft Sprocket & Nose Bearing

Cycle Works Tool Assembled Around Crankshaft Sprocket & Nose Bearing

I put some wheel bearing grease on the puller bolt threads and use two 1-1/8 inch box wrenches to tighten the puller bolt until I pull of the nose bearing and sprocket.

Removing Crankshaft Nose Bearing & Timing Sprocket with 1-1/8 Inch Box Wrenches

Removing Crankshaft Nose Bearing & Timing Sprocket with 1-1/8 Inch Box Wrenches

Crankshaft Nose Bearing & Timing Sprocket Pulled Loose

Crankshaft Nose Bearing & Timing Sprocket Pulled Loose

The nose bearing is made by FAG and is marked “16007A” and is a C3 tolerance.

Crankshaft Nose Bearing

Crankshaft Nose Bearing

Crankshaft Nose Bearing Identification

Crankshaft Nose Bearing Identification

Crankshaft Nose Bearing Identification (16007A) C3 Tolerance

Crankshaft Nose Bearing Identification (16007A) C3 Tolerance

The crankshaft timing sprocket fits on a key that is at the 9:00 position when the engine is at TDC. The teeth of the sprocket are off center. The wider side of the sleeve goes next to the engine block while the narrower side goes next to the nose bearing.

Crankshaft Sprocket Orientation-Wide Shoulder Toward Engine Block

Crankshaft Sprocket Orientation-Wide Shoulder Toward Engine Block

Crankshaft Nose with Key For Timing Sprocket (9:00 at TDC)

Crankshaft Nose with Key For Timing Sprocket (9:00 at TDC)

Crankshaft Timing Sprocket Keyway

Crankshaft Timing Sprocket Keyway

There is a spiral groove cut into the inside of the crankshaft timing sprocket hole. I checked with a knowledgeable BMW mechanic, Tom Cutter, of Rubber Chicken Racing Garage and he said “nothing to worry about”.

Spiral Groove Inside Crankshaft Timing Sprocket

Spiral Groove Inside Crankshaft Timing Sprocket

Groove Inside Crankshaft Timing Sprocket

Groove Inside Crankshaft Timing Sprocket

 

 

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.