11 BMW 1983 R80ST Replace Timing Chain, Crankshaft Sprocket & Nose Bearing

This “project” bike has over 63,000 miles on it. It’s not uncommon for the timing chain and crankshaft sprocket to wear enough at that mileage to affect valve timing. Too much slack causes uneven timing of the valves. If valve timing varies, then ignition timing will not be optimal. In situations with a lot of wear, the chain can be heard slapping inside the motor. As I’ve never heard this bike run, I do not know if the timing chain is that loose, but that much slop in the timing chain is more common at 100,000+ miles on the chain.

I want this bike to be as reliable as possible because I will auction it for charity to support the Motorcycle Relief Project. So I am replacing the timing chain, the crankshaft timing sprocket, the crankshaft nose bearing, the timing chain tensioner and the slide rail. This requires me to remove all the engine electrical components inside the front engine cover and remove the inner timing cover to get access to the timing chain components. I show how I remove the electrical components in this document.

Tools

I use special tools from Cycle Works to remove and install the crankshaft timing sprocket and the crankshaft nose bearing.

Cycle Works Crankshaft Timing Gear & Nose Bearing Puller Tool

Cycle Works Crankshaft Timing Gear & Nose Bearing Puller Tool

Cycle Works Tools For Installing Inner Timing Cover, Crankshaft Timing Sprocket & Nose Bearing

Cycle Works Tools For Installing Inner Timing Cover, Crankshaft Timing Sprocket & Nose Bearing

This link shows the three sets of engine tools,  Stage IStage II and Stage III., that  Cycle Works provides that include the components above.

I also use MAP gas (you can use propane) to heat the inner timing cover so I can remove it.

MAP Gas, Or Propane, To Heat Around Crankshaft Nose Bearing Boss

MAP Gas, Or Propane, To Heat Around Crankshaft Nose Bearing Boss

Parts

All the parts I need for replacing the timing chain components were supplied by Euro MotoElectrics for free in support of the Motorcycle Relief Project. EME provides a kit, EME Part# TCSimplex, with all the parts to upgrade the timing chain components. In addition, I got the crankshaft timing chain sprocket and crankshaft nose bearing. The inner timing cover gaskets are included in EME’s engine gasket kit, EME Part# GSK-EngineKit421

Part #                 Description                                                                 Qty
BMW Part No
11 31 1 338 185
11 31 1 335 576
11 31 1 335 579
11 31 1 335 584
11 31 1 335 934
EME Timing Chain Kit:
-Chain Tensioner
-Slide Rail
-Piston
-Coil Spring
-Timing Chain
1
1
1
1
1
11 21 1 335 586 SPROCKET, Crankshaft Timing Chain 1
07 11 9 981 722 GROOVED BALL BEARING – 160 07, Front Crankshaft Nose Bearing 1
07 11 9 932 841 CIRCLIP – D=6MM, Chain Tensioner Pivot 1
11 14 1 338 428 GASKET, Inner Timing Cover
(EME Gasket Kit)
1
11 14 1 338 429 WASHER-GASKET, Inner Timing Cover
(EME Gasket Kit)
2

Video

Here are some short videos summarizing this work.

VIDEO: 1983 BMW R80ST Remove Timing Chain, Crankshaft Sprocket & Nose Bearing

VIDEO: 1983 BMW R80ST Install Crankshaft Sprocket And Nose Bearing

VIDEO: 1983 BMW R80ST Install Timing Chain

VIDEO: 1983 BMW R80ST Install Inner Timing Cover

Remove Inner Timing Cover

I show how to do this on the 1983 R100RS. In that document I show how to use the Cycle Works tools to remove the inner timing cover.

On the 1983 R80ST I use the “heat the inner timing cover” method as described below. The inner timing cover is secured by nine Allen bolts and three special Allen nuts. There is also a thick flat washer under the head of each bolt and under the nuts.

Inner Timing Cover Allen Bolts

Inner Timing Cover Allen Bolts

Inner Timing Cover Allen Bolts

Inner Timing Cover Allen Bolts

Inner Timing Cover Left Side-Two Allen Nuts

Inner Timing Cover Left Side-Two Allen Nuts

Inner Timing Cover Right Side-Allen Nut At Top, Allen Bolt At Bottom

Inner Timing Cover Right Side-Allen Nut At Top, Allen Bolt At Bottom

Inner Timing Cover Fastener Type Locations

Inner Timing Cover Right Side-Allen Nut At Top, Allen Bolt At Bottom

After I remove the Allen nuts and bolts, I put them on a piece of cardboard with an outline of the timing cover and the locations of the blots and nuts. This helps me be sure I have all the hardware. I tape the three washers under the Allen bolts to the cardboard so I have all the hardware in one place.

Bolt Card Filled In with 3 Washers Under Allan Bolts

Bolt Card Filled In with 3 Washers Under Allan Bolts

I heat the inner timing cover boss around the front crankshaft seal. The crankshaft nose bearing is inside the boss and heating the aluminum inner timing cover will expand the boss so I can pull the inner timing cover off the nose bearing.

Heating Inner Timing Cover Around Crankshaft Nose Bearing Boss

Heating Inner Timing Cover Around Crankshaft Nose Bearing Boss

After heating for about a minute or two, I wiggle the inner timing cover as I pull it off the crankshaft nose bearing.

Pulling Inner Timing Cover Off

Pulling Inner Timing Cover Off

Outside Of Inner Timing Cover

Outside Of Inner Timing Cover

Inside Of Inner Timing Cover

Inside Of Inner Timing Cover

Marks On Inside Of Inner Timing Cover

Marks On Inside Of Inner Timing Cover

Crankshaft Nose Bearing

Crankshaft Nose Bearing

Components Inside Inner Timing Cover

This diagram below shows the components inside the inner timing cover. The diagram is from a 1983 R100RS that has the same components behind the inner timing cover as the R80ST.

Components Behind The Inner Timing Cover (From 1983 R100RS Engine, Same Components As 1983 R80ST Engine)

Components Behind The Inner Timing Cover (From 1983 R100RS Engine, Same Components As 1983 R80ST Engine)

Remove Timing Chain, Chain Tensioner & Chain Slider (aka, Rubbing Block)

I showed how I do this on a previous build of a 1983 R100RS which has the same components as the 1983 R80ST. You can read about that here.

Here are some pictures from the R80ST.

Set Engine To Top Dead Center (OT)

Set Engine To Top Dead Center (OT)

Camshaft Sprocket Alignment Mark: Will Be Either 12:00 or 6:00, Mine Is 6:00

Camshaft Sprocket Alignment Mark: Will Be Either 12:00 or 6:00, Mine Is 6:00

Crankshaft Timing Chain Gear Alignment Mark at 6:00 Position

Crankshaft Timing Chain Gear Alignment Mark at 6:00 Position

Crankshaft Timing Chain Alignment Mark On New Crankshaft Timing Chain Sprocket

Crankshaft Timing Chain Alignment Mark On New Crankshaft Timing Chain Sprocket

Timing Chain Master Link Orientation

Timing Chain Master Link Orientation

Fish Clip Orientation (Fish Swims Downstream)

Fish Clip Orientation (Fish Swims Downstream)

Remove Timing Chain Tensioner Arm Clip

Remove Timing Chain Tensioner Arm Clip

Timing Chain Tensioner Hardware Detail

Timing Chain Tensioner Hardware Detail

Front Side Of Slide Rail Has Curved Edge

Front Side Of Slide Rail Has Curved Edge

Slide Rail Nut Hardware Detail

Slide Rail Nut Hardware Detail

Slide Rail Bolt Hardware Detail

Slide Rail Bolt Hardware Detail

Back Side Of Slide Rail Has Square Edge

Back Side Of Slide Rail Has Square Edge

Remove Crankshaft Timing Chain Sprocket & Nose Bearing

I showed how I do this on a previous build of a 1983 R100RS which has the same components as the 1983 R80ST. You can read about that here.

Here are some pictures from the R80ST.

Cycle Works Crankshaft Timing Gear & Nose Bearing Puller Tool

Cycle Works Crankshaft Timing Gear & Nose Bearing Puller Tool

Cycle Works Sprocket Puller Sleeve-Wide Shoulder and Thin Shoulder

Cycle Works Sprocket Puller Sleeve-Wide Shoulder and Thin Shoulder

Orientation Of Cycle Works Puller In Sleeves, Against Wide Shoulder

Orientation Of Cycle Works Puller In Sleeves, Against Wide Shoulder

Crankshaft Timing Sprocket Wide Shoulder Goes Next to Engine Block

Crankshaft Timing Sprocket Wide Shoulder Goes Next to Engine Block

New Crankshaft Timing Sprocket Wide Shoulder Goes Next to Engine Block

New Crankshaft Timing Sprocket Wide Shoulder Goes Next to Engine Block

Original Crankshaft Timing Sprocket & Nose Bearing

Original Crankshaft Timing Sprocket & Nose Bearing

Crankshaft Timing Sprocket Teeth Inspection

Crankshaft Timing Sprocket Teeth Inspection

Crankshaft Timing Sprocket Teeth Inspection-Some Wear On Top Of Teeth

Crankshaft Timing Sprocket Teeth Inspection-Some Wear On Top Of Teeth

Crankshaft Timing Sprocket Teeth Inspection

Crankshaft Timing Sprocket Teeth Inspection-Some Wear On Top Of Teeth

New Crankshaft Timing Sprocket Teeth

New Crankshaft Timing Sprocket Teeth

Install Crankshaft Timing Chain Sprocket & Nose Bearing

The 1983 R100RS uses the same components as the 1983 R80ST. I replaced the crankshaft sprocket and nose bearing. This document for the 1983 R100RS shows how I install the crankshaft sprocket & nose bearing.

Here are some pictures from the 1983 R80ST.

Dirty, Oily Top Of Engine Block

Dirty, Oily Top Of Engine Block

Clean Top Of Engine Block

Clean Top Of Engine Block

Auto Sol Metal Cleaner To Clean Up Crankshaft Journal

Auto Sol Metal Cleaner To Clean Up Crankshaft Journal

Result From Cleaning Crankshaft Journal

Result From Cleaning Crankshaft Journal

Index Mark On Crankshaft Timing Sprocket Tooth

Index Mark On Crankshaft Timing Sprocket Tooth

Paint Applied To Crankshaft Timing Sprocket Index Tooth

Paint Applied To Crankshaft Timing Sprocket Index Tooth

Paint Applied To Camshaft Sprocket Index Dot

Paint Applied To Camshaft Sprocket Index Dot

Cycle Works Tool For Installing Crankshaft Timing Sprocket & Nose Bearing

Cycle Works Tool For Installing Crankshaft Timing Sprocket & Nose Bearing

Cycle Works Sleeve End For Crankshaft Timing Sprocket

Cycle Works Sleeve End For Crankshaft Timing Sprocket

Cycle Works Sleeve End For Nose Bearing

Cycle Works Sleeve End For Nose Bearing

Lard For Lubrication Of Crankshaft Journal

Lard For Lubrication Of Crankshaft Journal

Applying Lard To Crankshaft Journal

Applying Lard To Crankshaft Journal

Crankshaft Journal Woodruff Key

Crankshaft Journal Woodruff Key

Crankshaft Nose Bearing Markings

Crankshaft Nose Bearing Markings

Setting Up Cycle Works Tool For Installing Nose Bearing

Setting Up Cycle Works Tool For Installing Nose Bearing

Crankshaft Timing Sprocket & Nose Bearing Installed

Crankshaft Timing Sprocket & Nose Bearing Installed

Check Crankshaft Nose Bearing Is Against End Of Timing Sprocket

Check Crankshaft Nose Bearing Is Against End Of Timing Sprocket

Verify Crankshaft Timing Sprocket Is Against Shoulder Of Crankshaft Journal

Verify Crankshaft Timing Sprocket Is Against Shoulder Of Crankshaft Journal

Install Timing Chain

The 1983 R100RS uses the same timing chain components as the 1983 R80ST. I replaced the timing chain, the chain tensioner arm, spring and piston, and the timing chain rubbing block. This document for the 1983 R100RS shows how I install the timing chain.

Here are some pictures from the 1983 R80ST.

New Timing Chain

New Timing Chain

Timing Chain Tensioner & Rubbing Block Hardware Detail

Timing Chain Tensioner & Rubbing Block Hardware Detail

Check Of Alignment Marks After Installing Timing Chain

Check Of Alignment Marks After Installing Timing Chain

Removing Blue Shop Towel From Hole In Engine Block

Removing Blue Shop Towel From Hole In Engine Block

Removing Blue Shop Towel From Hole In Engine Block

Removing Blue Shop Towel From Hole In Engine Block

Crankshaft Timing Sprocket, Nose Bearing & Timing Chain Installed

Crankshaft Timing Sprocket, Nose Bearing & Timing Chain Installed

Install Inner Timing Cover and Front Crankshaft Seal

The 1983 R100RS uses the same inner timing cover and front crankshaft seal as the 1983 R80ST. I replace the inner timing cover gasket and the two donut gaskets and the crankshaft front seal. This document for the 1983 R100RS shows how I install the inner timing cover and front crankshaft seal.

Before I install the inner timing cover, I bead blast and paint the timing cover. You can read about how I do that work here.

Here some pictures from the 1983 R80ST. These show how I clean the engine block and remove the inner timing cover gasket using a razor blade and 600 & 1000 grit wet/dry sandpaper to remove small bits of gasket stuck on the engine block, and the mating surface of the inner timing cover.

Dirty, Oily Top Of Engine Block

Dirty, Oily Top Of Engine Block

Clean Top Of Engine Block

Clean Top Of Engine Block

Razor Blade, 600 Grit, 1000 Grit Wet/Dry Paper For Cleaning Off Inner Timing Cover Gasket

Razor Blade, 600 Grit, 1000 Grit Wet/Dry Paper For Cleaning Off Inner Timing Cover Gasket

Using Razor Blade Carefully To Separate Inner Timing Cover Gasket From Engine Block

Using Razor Blade Carefully To Separate Inner Timing Cover Gasket From Engine Block

Old Inner Timing Cover Gasket Removed

Old Inner Timing Cover Gasket Removed

Engine Block After Cleaning Off Inner Timing Cover Gasket

Engine Block After Cleaning Off Inner Timing Cover Gasket

I also make sure I remove the blue shop towel I put in the hole of the engine block when I installed the timing chain.

Removing Blue Shop Towel From Hole In Engine Block Before Installing Inner Timing Cover

Removing Blue Shop Towel From Hole In Engine Block Before Installing Inner Timing Cover

Removing Blue Shop Towel From Hole In Engine Block Before Installing Inner Timing Cover

Removing Blue Shop Towel From Hole In Engine Block Before Installing Inner Timing Cover

I replace the front crankshaft seal. Using a 30 mm socket and hammer to remove the seal. I clean the bore with 600 wet/dry paper to remove any rubber bits of the seal before installing the new seal.

Use Large (30 mm) Socket And Hammer To Remove Crankshaft Front Seal From Inner Timing Cover

Use Large (30 mm) Socket And Hammer To Remove Crankshaft Front Seal From Inner Timing Cover

Debris From Crankshaft Front Seal Stuck In Bore

Debris From Crankshaft Front Seal Stuck In Bore

Crankshaft Front Seal Bore After Sanding With 600 Wet/Dry Paper

Crankshaft Front Seal Bore After Sanding With 600 Wet/Dry Paper

Heating Around Boss For Front Crankshaft Seal

Heating Around Boss For Front Crankshaft Seal

Oiling Crankshaft Front Seal

Oiling Crankshaft Front Seal

I apply engine assembly lube on the timing chain, crankshaft and camshaft timing sprockets and around the ball bearings of the nose bearing. This ensures the timing chain is lubricated during the first engine start so the parts are not damaged due to lack of lubrication.

Engine Assembly Lube

Engine Assembly Lube

Applying Engine Assembly Lube To Sprockets, Chain & Nose Bearing Before Installing Inner Timing Cover

Applying Engine Assembly Lube To Sprockets, Chain & Nose Bearing Before Installing Inner Timing Cover

I clean the engine block and the inner timing cover mating surface with alcohol wipes to remove any oil or grease so the inner timing cover gasket will seal to the block and cover with it’s heat activated glue. Then I put some oil on the outer race of the nose bearing so it will slide more easily into the boss of the inner timing cover.

Using Alcohol Wipes To Clean Engine Block and Mating Surface Of Inner Timing Cover

Using Alcohol Wipes To Clean Engine Block and Mating Surface Of Inner Timing Cover

Oiling Outside Of Nose Bearing

Oiling Outside Of Nose Bearing

I heat the inner timing cover in the oven at 250 F before putting it on. I use the Cycle Works tool to press the inner timing cover tightly against the engine block. Then I verify that the two donut gaskets that fit around the top timing cover bolts are correctly in place.

Cycle Works Tool Used To Install Inner Timing Cover Over Nose Bearing

Cycle Works Tool Used To Install Inner Timing Cover Over Nose Bearing

Verify Gasket "Donuts" Are In Place

Verify Gasket “Donuts” Are In Place

Verify Gasket "Donuts" Are In Place

Verify Gasket "Donuts" Are In Place

Verify Gasket “Donuts” Are In Place

I torque the inner timing cover Allen bolts and nuts to 72 INCH-Lbs (NOT FOOT-LBS) in three stages; 30, 60 and 72 INCH-Lbs. Before I complete the final stage to 72 INCH-Lbs, I use my heat gun to heat boss around the nose bearing for 2 to 3 minutes to heat it and ensure the nose bearing is seated all the way in the boss.

Heating Around Nose Bearing Boss Before Torqueing To Final 72 INCH-Lbs

Heating Around Nose Bearing Boss Before Torqueing To Final 72 INCH-Lbs

Torque Inner Timing Cover Allen Bolts & Nuts To 72 INCH-Lbs

Torque Inner Timing Cover Allen Bolts & Nuts To 72 INCH-Lbs

Here is the final result.

Inner Timing Cover Installed

Inner Timing Cover Installed

Inner Timing Cover Installed

Inner Timing Cover Installed

6 thoughts on “11 BMW 1983 R80ST Replace Timing Chain, Crankshaft Sprocket & Nose Bearing

  1. Hello Brook,
    IT seems (picture is not very clear) that there are washers under the 3 nuts on the cover.
    On my 1982 R65, there are none and the fiche does not show washers on this place ?
    Did you add them or are these OEM ?
    Because I’m surprised my bike miss them ?
    Have a nice day !

    • Georges,

      There should be a washer, part# 07 11 9 904 606, under each Allen nut. The fiche has “X” for the number of flat washers, which isn’t helpful. If someone removed the timing cover they may not have noticed the flat washers under the Allen nuts and lost them. They will fall out when the cover is turned over.

      Best.
      Brook.

  2. Brook,

    First, thanks for all this excellent information and sharing your projects. It is invaluable to the community. I am new to airheads, but not mechanicals and seeing the detailed ins and outs is excellent.

    My current project is an 85 R80 rebuild and I was not as lucky as you seem to be when installing the crankshaft sprocket. My new sprocket would simply not go on at 350 degrees. In the end, I had to go north of 400 to get it on and still needed to use the cycle works tool to drive it home. It took a while for me to commit to doing that as your video on this shows it simply sliding on. Mine would bind once it reached the smaller inner dimension on the sprocket and almost immediately cool down to the point of needing to remove it with the puller assembly.

    In the end, I am pretty sure it’s on correctly. It’s fully seated and inline with the cam sprocket so the chain is straight. Still I am wondering how uncommon this is.

    Thanks again for everything.

    Bill

  3. Brook,

    Awesome tutorials throughout. Thank you for taking the time to share with us all. It is most helpful.

    One question: Do you use any kind of gasket sealant when replacing gaskets as you did in this section regarding the inner timing gasket?

    Justin

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