Q: How to adjust rear wheel drive play

[Dave334478]

Hey guys,

 

I'm looking for some advice on how to get the play out of the rear end.

 

I just got this bike, this is only the third time I've ridden it, all very short rides. I took it down an asphalt rode that is in very bad condition to see how it rode. I heard some rattling so when I got home I started  kicking stuff.

When I support it with the rear wheel in the air, I can grab the top and bottom of the rear wheel and feel play in it. I assume there should be none. I can also hear a clunk when I hit the bottom of the rear tire in an upward direction with my fist.

 

I set up my dial indicator on the rear strut  next to bolt #5 (the only thing a magnet will stick to) and head of bolt #3 in the pic and I'm get 4-5 thousands of movement on the needle when grab I the top and bottom of the wheel and move it side to side. The entire rear hub is twisting slightly.

Looking at the simple repair manual I got my hands on, the one this pic is from, it looks like I need to loosen the lock nut on bolt 4, then tighen the inner bolt to get rid of the play, then retighten the lock nut.

 

If I'm reading the the book right, I remove bolt 4, take the lock nut off, clean all the old thread locker off both parts and the hole it goes in. Then I coat the bolt with new loctite, screw it in and tighten it to 7 Nm. Then put I on the lock nut and tighten it to 105 Nm.

My experience with locknuts like this is they usually cause the nut they are locking to pull back slightly decreasing the pressure they were applying to what ever they are applying it to.

Can someone who has experience doing this share the proper procedure with me please?

 

PS should I use the High Strength Loctite 268 (Red) or go with the Medium Strength Loctite 248 (Blue)?

 

[9Mary7]

You will need to heat the bolt to get the red thread locker to soften, heat gun is usually best but I've seen it done with a torch........ just gotta avoid scorching the swing arm paint. It can be done if you are careful. I do NOT use red thread locker when assembling. Does not need it and I believe BMW says to not use it again. Blue is fine. Carefully cleaning the threaded aluminum is key.

I'm sure Dirt Rider will chime in when he has time.

[Dave334478]

Thanks for the tips.

 

I'm mostly concerned with the proper procedure for tightening it. Should I remove the wheel to take the weight off or do I want the weight on?  Do I really want to tighten it to 7 Nm or should I go a bit more to be sure that pressure is maintained after I tighten the lock nut?

 

Stuff like that. The stuff you don't find in the books ;)

[fatbob]

You have to remove the wheel to do it right.   BTW there is an excellent update to these bearings available at a reasonable price.   Search Kirk Johnson’s tutorial videos, final drive pivot bearings.   

[dirtrider]

14 hours ago, Dave334478 said:

Hey guys,

 

I'm looking for some advice on how to get the play out of the rear end.

 

I just got this bike, this is only the third time I've ridden it, all very short rides. I took it down an asphalt rode that is in very bad condition to see how it rode. I heard some rattling so when I got home I started  kicking stuff.

When I support it with the rear wheel in the air, I can grab the top and bottom of the rear wheel and feel play in it. I assume there should be none. I can also hear a clunk when I hit the bottom of the rear tire in an upward direction with my fist.

 

I set up my dial indicator on the rear strut  next to bolt #5 (the only thing a magnet will stick to) and head of bolt #3 in the pic and I'm get 4-5 thousands of movement on the needle when grab I the top and bottom of the wheel and move it side to side. The entire rear hub is twisting slightly.

Looking at the simple repair manual I got my hands on, the one this pic is from, it looks like I need to loosen the lock nut on bolt 4, then tighen the inner bolt to get rid of the play, then retighten the lock nut.

 

If I'm reading the the book right, I remove bolt 4, take the lock nut off, clean all the old thread locker off both parts and the hole it goes in. Then I coat the bolt with new loctite, screw it in and tighten it to 7 Nm. Then put I on the lock nut and tighten it to 105 Nm.

My experience with locknuts like this is they usually cause the nut they are locking to pull back slightly decreasing the pressure they were applying to what ever they are applying it to.

Can someone who has experience doing this share the proper procedure with me please?

 

PS should I use the High Strength Loctite 268 (Red) or go with the Medium Strength Loctite 248 (Blue)?
 

Morning Dave

 

You have a lot going on there so let's start from the beginning. 

 

The way that you measured the rear play also included the rear wheel bearing (crown bearing) so before disassembling anything you need to figure out how much of your movement is in the  wheel bearing & how much is in the rear pivot pins.

 

To measure the rear crown bearing play you need to set you dial indicator to measure between the final drive housing & the wheel rim. Anything external to the actual final drive housing will give you combined movement & won't identify what is wrong.   

 

If all you have is  magnetic base dial indicator  then you can clamp on a pair of 'butcher pliers' (Vise Grips) then stick your magnetic base on those.

 

Once you have the rear wheel bearing (crown bearing)  movement identified then you can subtract that from the overall movement that you have already measured  (using the rubber isolated  rear torque link as a base to measure from is not a good way to measure but it is what it is).

 

OK, once you have your crown bearing movement identified you will have a repair direction to follow (the crown bearing is originally set to just slightly tighter than "O" movement,  or set to  an actual preload so any movement in that is not good). 

 

On re-doing the rear pivot pin adjustment, if that thing has been rattling around on loose pivot pins then it has more than likely beaten all the grease out of the small needle bearings so a re-greasing (or bearing replacement)  is recommended. Operating while loose usually Brinell's the bearing races so keep that in mind. 

 

To remove the pivot pins you need to heat the pivot stud to just under 250°f, I usually use a small high-heat gun to heat the pivot pin & the housing around it (not hot enough to damage the housing paint), THEN I use a small pin-point torch to heat the inside of the pivot pin hex to hot enough to break the Lock-Tight loose. 

 

If you try to heat it all with a large head heat gun you will probably scorch the paint, if you don't heat it enough & try to  break it free with brute force then you chance stripping those fragile threads out of the alloy housing  & ruining the housing.   

 

As for the 7nm pin torque at re-assembly, that is too low for a proper torque with the drive weight hanging on the pins, so try to neutralize the hanging weight as best you can. Personally I usually use 10nm as over the years that has proven to work out the best. I also usually torque to about 12-14nm on first install, then back off & re-torque to the 10nm for final. 

 

As for Lock-Tite on re-assembly, personally I usually use blue 242, that seems to work good but 242 does take time to cure on the alloy threads. 

 

So start with measuring the crown bearing play measurement then we can work from there.   

 

 

 

 

[Dave334478]

11 hours ago, fatbob said:

You have to remove the wheel to do it right.   BTW there is an excellent update to these bearings available at a reasonable price.   Search Kirk Johnson’s tutorial videos, final drive pivot bearings.   

I watched the video but there was no mention of getting new bearings for "a reasonable price".  Can you elaborate on this please? 

 

5 hours ago, dirtrider said:

Morning Dave

 

You have a lot going on there so let's start from the beginning. 

 

The way that you measured the rear play also included the rear wheel bearing (crown bearing) so before disassembling anything you need to figure out how much of your movement is in the  wheel bearing & how much is in the rear pivot pins.

 

To measure the rear crown bearing play you need to set you dial indicator to measure between the final drive housing & the wheel rim. Anything external to the actual final drive housing will give you combined movement & won't identify what is wrong.   

 

If all you have is  magnetic base dial indicator  then you can clamp on a pair of 'butcher pliers' (Vise Grips) then stick your magnetic base on those.

 

Once you have the rear wheel bearing (crown bearing)  movement identified then you can subtract that from the overall movement that you have already measured  (using the rubber isolated  rear torque link as a base to measure from is not a good way to measure but it is what it is).

 

OK, once you have your crown bearing movement identified you will have a repair direction to follow (the crown bearing is originally set to just slightly tighter than "O" movement,  or set to  an actual preload so any movement in that is not good). 

 

On re-doing the rear pivot pin adjustment, if that thing has been rattling around on loose pivot pins then it has more than likely beaten all the grease out of the small needle bearings so a re-greasing (or bearing replacement)  is recommended. Operating while loose usually Brinell's the bearing races so keep that in mind. 

 

To remove the pivot pins you need to heat the pivot stud to just under 250°f, I usually use a small high-heat gun to heat the pivot pin & the housing around it (not hot enough to damage the housing paint), THEN I use a small pin-point torch to heat the inside of the pivot pin hex to hot enough to break the Lock-Tight loose. 

 

If you try to heat it all with a large head heat gun you will probably scorch the paint, if you don't heat it enough & try to  break it free with brute force then you chance stripping those fragile threads out of the alloy housing  & ruining the housing.   

 

As for the 7nm pin torque at re-assembly, that is too low for a proper torque with the drive weight hanging on the pins, so try to neutralize the hanging weight as best you can. Personally I usually use 10nm as over the years that has proven to work out the best. I also usually torque to about 12-14nm on first install, then back off & re-torque to the 10nm for final. 

 

As for Lock-Tite on re-assembly, personally I usually use blue 242, that seems to work good but 242 does take time to cure on the alloy threads. 

 

So start with measuring the crown bearing play measurement then we can work from there.   

 

 

 

 

 

Thanks dirtrider.

 

That sentence "As for the 7nm pin torque....." is priceless information. That's exactly the kind of info I was looking for.

 

One thing, the way I measured, however inaccurate, would not include any crown bearing play. I would have felt any crown bearing play with my hands because that is originally what I was trying to do but, it would not have affected the dial indicator because of the locations of the two points where it was making contact.

 

I tossed it on there only to confirm what I saw, not to try and get an accurate measurement. When looking down the drive/arm at the two hose clamps on the rubber boot, I can see the rear one rotating, ever so slightly, in relation to the front one when I move the wheel by hand.

I've already read the section on shimming the housing cover. I'm hoping I won't need to do that as I see them using a "measuring ring, BMW No. 33 2 601" which I'm sure is insanely expensive and that I obviously don't have.

I'm hoping I can just tighten up the rear pivot pins and that will be enough to to keep the bike rideable for now. 

 

As for measuring rear wheel bearing play, that is where I started. My manual simply says to check for play by hand and if there any, renew the wheel bearings. Well since there is play in the pivot bearings, I can't tell that way.

 

I have several large rubber tipped spring clamps I can use to clamp a flat piece of metal on to one of the alloy wheel spokes and mount my mag base on that.

If I find there's wheel bearing play too, I'll be back asking if you know a way to calculate the shim thickness with out using "extremely overpriced tool #42".

[dirtrider]

2 hours ago, Dave334478 said:

As for measuring rear wheel bearing play, that is where I started. My manual simply says to check for play by hand and if there any, renew the wheel bearings. Well since there is play in the pivot bearings, I can't tell that way.

 

If I find there's wheel bearing play too, I'll be back asking if you know a way to calculate the shim thickness with out using "extremely overpriced tool #42".

Afternoon Dave

 

Best way to get an accurate bearing wear/preload measurement is to measure in the 3 o'clock 9 o'clock direction not the 6 & 12 direction.   

 

Yes, you can set the crown bearing preload without using the BMW tools & fixture. 

 

There are a number of ways  from using soft solder without a shim or seal then measuring the solder crushed thickness, to determine the gap, then subtract the preload from that measurement.

 

Or installing the ring gear & spool without a shim & seal then lightly heating the cover in the bearing area, then measuring the spool side to side movement with a dial indicator, then subtract the preload from that measurement.  

 

Or, install the cover with no "O" ring & no seal using a very thick (known thickness) over-thick shim, then install 3 lubricated  bolts & very lightly adjust the cover to have an even gap all the way around with no actual bearing preload, then precisely measure the cover to drive gap with precision feeler gage stock, then subtract the preload from that. 

 

Most will sort of work but it takes a LOT of common sense & an educated  feel for what is or is not giving you correct data back. 

 

Personally I set the final drive housing up on my granite surface plate, then measure the installed bearing height vs final drive housing cover mating surface. Then I set the cover up on the surface plate & precision measure the cover mating surface to bottom of  bearing cavity. Then I subtract the needed preload &  install the correct shim. (this takes a precise (repeatable) height gauge).    

 

Added: on adding a metal plate to an  alloy wheel (or other alloy area) I usually just use hot glue, that holds pretty good & if you only use a couple of small glue areas the glue  remnants will peel off pretty easily when done.

[The Fabricator]

What bike do you have?  Mileage?

I have 2000 R1150GS.  30k miles. It has perceptible play in the rear wheel.   I guess 10 thou at the rim.  And this is my second final drive-mileage unknown. [I geared down with a R1100RT final]  Both have similar free play.   I haven't measured it.  All the pivots are tight.

Any old  oil head I have laid my hands on [5?] has had rear wheel play.

I monitor the rear wheel play and it hasn't changed.

I don't hear any rattle from the rear end.  I am skeptical there  would be any noise to be heard over road/engine noise.  I would look else where for the noise.

The pivot  pins are easy to adjust.  The final drive bearing play not so much.  

To separate wheel brg play from final drive pin play from swing are pin play, hold your finger between any 2 parts [wheel-final drive, final drive-swing arm, swing arm-frame] and wiggle [the wheel is easiest].  You may need an assistant.

 

[Dave334478]

2 hours ago, dirtrider said:

Afternoon Dave

 

Best way to get an accurate bearing wear/preload measurement is to measure in the 3 o'clock 9 o'clock direction not the 6 & 12 direction.   

 

Yes, you can set the crown bearing preload without using the BMW tools & fixture. 

 

There are a number of ways  from using soft solder without a shim or seal then measuring the solder crushed thickness, to determine the gap, then subtract the preload from that measurement.

 

Or installing the ring gear & spool without a shim & seal then lightly heating the cover in the bearing area, then measuring the spool side to side movement with a dial indicator, then subtract the preload from that measurement.  

 

Or, install the cover with no "O" ring & no seal using a very thick (known thickness) over-thick shim, then install 3 lubricated  bolts & very lightly adjust the cover to have an even gap all the way around with no actual bearing preload, then precisely measure the cover to drive gap with precision feeler gage stock, then subtract the preload from that. 

 

Most will sort of work but it takes a LOT of common sense & an educated  feel for what is or is not giving you correct data back. 

 

Personally I set the final drive housing up on my granite surface plate, then measure the installed bearing height vs final drive housing cover mating surface. Then I set the cover up on the surface plate & precision measure the cover mating surface to bottom of  bearing cavity. Then I subtract the needed preload &  install the correct shim. (this takes a precise (repeatable) height gauge).    

 

Soft solder as plastigauge? That's one I never thought of You have a f****** granite slab!? I am so jealous.

 

So, good news! I didn't detect any play in the rear wheel bearing. I checked it, then spun the wheel 90 and rechecked it, 0 movement. 

 

The rear brake disc is steel and non floating (doh!). 

So I'm back to tightening up the pivot bearing. I ordered a heat gun because frankly, I've needed one for many projects and have always made due without. No more though, I don't want to risk damaging the threads in the housing. 

With your advice on the best way to take care of that, I think I have everything covered.  I'll be back to either share how it works out, or ask more questions.

 

Thanks again.

 

59 minutes ago, The Fabricator said:

What bike do you have?  Mileage?

I have 2000 R1150GS.  30k miles. It has perceptible play in the rear wheel.   I guess 10 thou at the rim.  And this is my second final drive-mileage unknown. [I geared down with a R1100RT final]  Both have similar free play.   I haven't measured it.  All the pivots are tight.

Any old  oil head I have laid my hands on [5?] has had rear wheel play.

I monitor the rear wheel play and it hasn't changed.

I don't hear any rattle from the rear end.  I am skeptical there  would be any noise to be heard over road/engine noise.  I would look else where for the noise.

The pivot  pins are easy to adjust.  The final drive bearing play not so much.  

To separate wheel brg play from final drive pin play from swing are pin play, hold your finger between any 2 parts [wheel-final drive, final drive-swing arm, swing arm-frame] and wiggle [the wheel is easiest].  You may need an assistant.

 

 

97 R1100R, 55k on it. 

 

It had the 50k service done at the dealer in 01 @ 51k mi, then ended up sitting for many years. It was taken back to the dealer about 18 mo ago with instructions to "make it like new". Then it was ridden often for about 6 months. Next it went back to sitting for another year and was just given to me (to keep it in the family) a few weeks ago. All I had to do was put in a new battery and wash it.

 

The play, measured by eye at the edge of the rear tire, is about 100 thou. It makes a hollow clunk when you grab the top and bottom of the tire and move it back and forth.

 

Still, that might not have been what was making the sound I heard but it's something I need to take care of before I feel the bike is safe to ride again.

 

PS No my bike isn't in the living room. Yes my garage is carpeted (no padding). Working under a car while laying on nice carpet is freaking awsome. 
 

[Dave334478]

Final Update:

 

So, I've got everything off and I'm ready to start on the pivot bearing bolt. I pop a 30mm on my 23" snap-on 1/2" breaker bar and give the locknut some gentle tugs hoping I can take it off before I start heating the pivot bolt.

 

To my suprise it came loose very easy, spinning the pivot bolt as well. Turns out, there was no lock tight at all on it. In fact, the threads had PTFE on them FFS! 

 

Luckily nothing was damaged and the bearings still had grease in them. So I inspected and cleaned everything up and reassembled it all properly and there's 0 play in the rear end now.

 

In the proccess I found the rattle. The clamp on the exhuast slip joint was completly loosened. It must have moved forward onto the header pipe when I test drove down the rough road.

Until next time..... Which is going to be in just a few minutes because now I have a new question ;)
 

[fatbob]

Dave:

when I say “at a reasonable price” that is in the realm of BMW parts.    The solid brass bushings noted cost less than the BMW parts they replace.   

[Dave334478]

54 minutes ago, fatbob said:

Dave:

when I say “at a reasonable price” that is in the realm of BMW parts.    The solid brass bushings noted cost less than the BMW parts they replace.   

 

Your first sentence there is an oxymoron. 

 

Luckily they were only loose.