Chocolate Gear Oil?

[kiwiaudio]

Of course there is a delay when I need one !!

I wonder - Is this washer tool steel, or common garden mild steel. I have access to a machine shop @ work. Perhaps I can have these made !

[SageRider]

Some energy must be getting transferred to the outer race, surely Sageriders disaster ruined the case - yes?

Yes, the rear case was replaced due to damage caused by the bearing outer race spinning and gouging the case surface.

[Bart Anderson]

Look closely at Michael's pics with the bare inner race.

 

 

Two things in particular strike me. First, it looks like the inner race is still mostly intact, but its face is mangled. Second, it doesn't look like the wear on the gear face and the inner race is any worse than Seth's or Mark's. Yet the gear has clearly gotten mangled on the outer race. How can that be?

 

It has to be that the inner and outer races have become radically out of alignment. I think the bearings failed first, causing the seal failure and the chocolate gear oil, and then disintigrating to the point where the shaft and inner race could move far enough back in the case for the gear to contact the outer race and become chewed up by it.

 

I think the bearings fail because they see an axial load they're not designed for...meaning the inner race is moving axially relative to the outer race. Since the inner race isn't going to move on the shaft because of the machined lip on one side and the clip and spacer on the other side, this can only happen if the whole shaft is moving relative to the outer race. The shaft can only move if it's allowed to, through improper shimming.

 

That's my story and I'm stiking to it.

 

One thing that has me thinking - How is the relatively weak alloy case putting up with this hammering? Some energy must be getting transferred to the outer race, surely Sageriders disaster ruined the case - yes?

 

A local rider, Tom Roe, actually punched his input shaft through the back of the case on his RT. Needless to say, we closely examined my case for wear when we had it apart. If the shaft moves far enough that the gear can contact the outer race, I would thing the case would have to be toast too. Remember that the input shaft is the only shaft exposed on both ends of the case, so proper shimming of it is especially important.

[SageRider]

My rear case:

 

It's been 3 years since my tranny failure and rebuild so my memory is hazy at best about the internals.

 

A couple of questions:

1) What prevents the input shaft from axial movement in the case. To my recollection, only the sealed ball bearings.

 

2) What positions the bearings in the case? In my case, I do not recall the presence of any shims. The case had to be heated to separate and also to close. From my recollection of the heat applied, the transmission could get hot enough just from normal (or maybe high speed) running to allow the case grip on the outer race to release.

[kiwiaudio]

No dice on a stronger bearing. "This is as strong as you'll find" says the man. Translation: This is all I have to sell you !

Clutch is down to the rivets, so I'll replace that too. Friction plates survived, but stupid me forgot to mark the assy. before pulling it ! I've read that it doesn't matter much - offset the white dots 120deg. if visible.

Anyone have an aftermarket part number for the final drive pivot bearings?

[kiwiaudio]

"I guess these problems could be a result of Getrag not being used to building these transmissions for the additional horsepower of the oilheads. Or maybe the new engineers were originally from the old Peoples Democratic Republik, where 45 hp was a powerful motor."

 

This, from a few pages back, says it all I think !

[smiller]

[bart] I think the bearings fail because they see an axial load they're not designed for...meaning the inner race is moving axially relative to the outer race. Since the inner race isn't going to move on the shaft because of the machined lip on one side and the clip and spacer on the other side, this can only happen if the whole shaft is moving relative to the outer race. The shaft can only move if it's allowed to, through improper shimming.

If the shimming is too loose then the entire assembly (including the outer race) will be allowed to move, not just the inner race/shaft. Too tight a shim would increase the axial load on the bearing races, but too loose a shim would not. That's why a clearance is speced!

 

Also, why doesn't the front bearing show any sign of damage? It should be equally subject to the forces you describe.

 

Anyway, as I mentioned I'll be checking the OEM end float on my transmission shortly. Perhaps it will be grossly out of spec and if so that will be very interesting, but if it is within the recommended (.05 to .015mm) range I will maintain my doubt that end float has anything to do with this.

 

[Michael] From my recollection of the heat applied, the transmission could get hot enough just from normal (or maybe high speed) running to allow the case grip on the outer race to release.

I would guess that this is correct, else it wouldn't matter what shims were or weren't in there. And that's why the entire shaft (including bearings) floats as an assembly (at least to the extent that you can call .015mm 'floating.')

[flars]

"Anyone have an aftermarket part number for the final drive pivot bearings?"

When I replaced these on my bike last I could find no one who had them. I went to three different bearing houses.

However - you can get bushings to replace these with from a forum member. You will have to search for his name...

[smiller]

"Anyone have an aftermarket part number for the final drive pivot bearings?"

When I replaced these on my bike last I could find no one who had them. I went to three different bearing houses.

However - you can get bushings to replace these with from a forum member. You will have to search for his name...

Yes, the bearings seem to be a special order item for BMW and are not a standard size, or at least I don't know anyone who has found an alternate source for them yet. Tom Cutter offers a solid bushing replacement for the roller bearings if you want to go that way. FWIW I haven't found the stock items all that problematical but apparently many others have.

[kiwiaudio]

I just got off the phone with Tom, and he says the standard bearings fail often with the load from two up riding, or just a large dude! Understandable actually, they are a small needle roller bearing indeed and they are not sealed !

[Steve W.]

I'm now wondering if there is a stronger version of this NTN6304CU bearing available. I'll ask my local experts today. It's doubtful there is a difference in the metal, but maybe a stronger ball/race/cage version is available. Or maybe a better seal in the bearing? If so, this must help withstand whatever is going on !!

I think I'll get the seals while I'm there, so all BMW can get me for is this washer/spacer !

Have you heard back from your possible supplier on that Seth?

One thing that has me thinking - How is the relatively weak alloy case putting up with this hammering? Some energy must be getting transferred to the outer race, surely Sageriders disaster ruined the case - yes?

 

The early oily trannys had tapered rollers on these shafts. The tapered roller will take a larger thurst load than a ball. The pix of the bearing show it failed from thurst loading. Can a tapered roller be installed in place of the ball bearing. I know it would have to be shimmed to get the clearance correct. Why did BMW go to a sealed ball bearing? This looks like the perfect apli. for a tapered roller. I've done a lot of car, tractor, motorcycle, ect. trannys and this is the first I've seen with sealed bearings inside a oil filled tranny. The ball bearing may last longer without the seals and lubed by the oil. Looks like they took a step back with the sealed ball bearings. What's in the 6 speeds?

Steve W.

[kiwiaudio]

"A local rider, Tom Roe, actually punched his input shaft through the back of the case on his RT."

 

This comment suggests there is a lot more force being applied to this bearing than we are realizing. Or, it just blew apart like Michaels, but more dramatically !

[kiwiaudio]

Seth, my dealer could not find a match for the part # you gave for the M94 washer. Or do I have it wrong !

23211340794 ?

[Bart Anderson]

If the shimming is too loose then the entire assembly (including the outer race) will be allowed to move, not just the inner race/shaft. Too tight a shim would increase the axial load on the bearing races, but too loose a shim would not. That's why a clearance is speced!

 

Of course you're correct...the shims shim the outer race of the front bearing only, so they prevent the entire assembly (including the outer race) from moving around too much. They do nothing about axial load on the bearings, other than maybe preventing too much momentum being allowed.

 

Also, why doesn't the front bearing show any sign of damage? It should be equally subject to the forces you describe.

 

The force appears to be mostly rearward, so I presume the outer race of the front bearing is just being pulled from its seat in the case. The rear bearing, on the other hand, is being stopped by the case.

 

So it sounds like proper shimming probably won't prevent this problem. I still don't think the wave washer is the culprit, though, since its force cannot move the inner race of the rear bearing which is held in place on the shaft with that clip. The whole shaft has to be moving rearward.

[smiller]

So it sounds like proper shimming probably won't prevent this problem.

 

No, because it isn't the cause.

 

I still don't think the wave washer is the culprit, though, since its force cannot move the inner race of the rear bearing which is held in place on the shaft with that clip.

 

Correct, nothing moves the inner race of the rear bearing. Nothing has to. The problem is that the gear is apparently pounding against the rear bearing, which beings us back to...

 

Anyway, I've explained my view every way I can at this point and am kind of beat. Anyone following the thread will have to act as they feel appropriate based on what they're read, or if they can afford the time, wait a while until we have some results back from the mod.

[smiller]

Seth, my dealer could not find a match for the part # you gave for the M94 washer. Or do I have it wrong ! 23211340794 ?

This is what I ordered, item #3. Both Hammersley and Chicago BMW (two common BMW mail order vendors) list it as a valid and available part, although I wouldn't be surprised if it ends up on backorder. As I mentioned I don't have it yet but as far as I can tell it should close enough to what I need.

[kiwiaudio]

I can get this washer/spacer made for me for next to nothing, but only from mild steel. I believe the original is case hardened tool steel? The washers only function is as a spacer, but must be seeing load right?

I'm thinking it will be OK .....

I dunno - what do you think?

[DavidEBSmith]

Seth, according to the service manual and the parts fiche, the R1150RT also has a wave washer on the input shaft, like the M97 transmission. So if your theory is correct, the 1150s should exhibit this same failure.

 

This is where I think something is missing. It just doesn't happen that often. There's a lot of trannys with wave washers running around, many with high mileage, and this failure isn't common. Plus, the limited number of failures don't seem to show a pattern of failure as a function of mileage. There's a couple of relatively low mileage failures here, but on my bike, it was the wave washer that broke and was discovered at 80K miles (and who knows how long it was broken before I found it) - yet there was no other abnormal wear and tear. If anything, you'd expect that with the wave washer broken, the slamming would be worse (because it wouldn't be acting as a cushion), yet, there was no apparent problem.

 

So when you say they'll all eventually show this failure, I'm not convinced. Unless "eventually" is somewhere in 6-digit mileage, in which case it's hardly cause for panic because something else like splines or the final drive will break before then. It could well be a design issue, but I have to think that if it is, it's the design plus something else.

[smiller]

Seth, according to the service manual and the parts fiche, the R1150RT also has a wave washer on the input shaft, like the M97 transmission. So if your theory is correct, the 1150s should exhibit this same failure so whatever is happening is as yet going largely undetected.

 

This is where I think something is missing. It just doesn't happen that often. There's a lot of trannys with wave washers running around, many with high mileage, and this failure isn't common. Plus, the limited number of failures don't seem to show a pattern of failure as a function of mileage. There's a couple of relatively low mileage failures here, but on my bike, it was the wave washer that broke and was discovered at 80K miles (and who knows how long it was broken before I found it) - yet there was no other abnormal wear and tear. If anything, you'd expect that with the wave washer broken, the slamming would be worse (because it wouldn't be acting as a cushion), yet, there was no apparent problem.

I can't argue with any of your logic David. In fact the one factor that bugs me the most is indeed the question of 'if not all, why not all?'

 

So when you say they'll all eventually show this failure, I'm not convinced. Unless "eventually" is somewhere in 6-digit mileage, in which case it's hardly cause for panic because something else like splines or the final drive will break before then. It could well be a design issue, but I have to think that if it is, it's the design plus something else.

My opinion that this issue is more common than we think is based on the number of transmissions that I've heard of and seen with this problem (which I'll admit is decidedly less than the total number of transmissions produced. ) My guess would be that all transmissions with this design are affected, but for many/most it may in fact be be a 6-digit mileage issue. Or at least it may take that long for the bearing to hard fail, and if that is the case then the problem may be common but just not widely detected as yet.

 

This thread itself has provided more information, such as the lack of relationship of the severity of the damage to mileage, and the fact that yours showed no problem even without the wave washer (BTW did you actually pull the rear bearing and look? As we have seen often the problem is not visible until this is done) is even more confusing. I'll certainly buy the 'poor design... plus something else' theory, but man, I'm sure at a loss as to what that 'something else' might be. I'm just not comfortable ignoring it and putting the transmission back together in a stock configuration if I can't see any reason why the fault won't recur, and so far I can't.

 

But I'm certainly not trying to be Chicken Little here, rather just want to disseminate some information that others may find interesting/useful. I'm not suggesting that anyone panic, but I certainly would suggest that oilhead owners pay attention the the color of their drained transmission oil and if it is dark exercise some caution, such as perhaps get an oil sample analyzed at the least. Regardless of the frequency of occurrence, if you do have the problem it's one of those things where the fix will only get more expensive with time.

[DavidEBSmith]

(BTW did you actually pull the rear bearing and look? As we have seen often the problem is not visible until this is done)

 

The shop that did it replaced all the bearings and seals while they were in there and said there was nothing else unusual.

 

At least we do know for sure that if your transmission oil is dark and murky, get thee to a shop quickly. (Or if you find a large piece of metal on your drain plug, or lots of sparkles in your trans oil . . . )

[kiwiaudio]

I've had the original washer tested for strength and hardness and it is mild steel !

These are on a nationwide backorder list, so have your local machine shop make you a copy of your original spacer if you are inclined to trust Seths theory - Personally, I'm taking the plunge !

[kiwiaudio]

BTW - What is everyone using to reseal the transmission case halves?

[smiller]

BTW - What is everyone using to reseal the transmission case halves?

Any appropriate RTV sealant should work fine. Permatex Ultra Gray is designed for high-torque applications such as a transmission case, but Ultra Black or Blue would probably be OK as well.

[Flyer5]

Reading through this thread I am concerned about my bike I have 96k miles and I do have a slight knock when idleing in neutral . It goes away when the clutch is pulled in . It is a 2k r1100rt . The oil looked fine I changed it about 1500 miles ago ,before seeing this thread and really didnt pay that much attn to it there was some light metal on the drain plug but not a lot . Could this be the bearing or the wave washer . Or is a light noise normal ?I should add that I just got the bike 4k miles ago in march the noise hasen't gotten any worse ,its only when hot . Thanks ,Dave

[T__]

Reading through this thread I am concerned about my bike I have 96k miles and I do have a slight knock when idleing in neutral . It goes away when the clutch is pulled in . It is a 2k r1100rt . The oil looked fine I changed it about 1500 miles ago ,before seeing this thread and really didnt pay that much attn to it there was some light metal on the drain plug but not a lot . Could this be the bearing or the wave washer . Or is a light noise normal ?I should add that I just got the bike 4k miles ago in march the noise hasen't gotten any worse ,its only when hot . Thanks ,Dave

 

Dave, neutral gear rattle is normal on the BMW boxer bikes.. Due to the harsh power pulses of the boxer twin at idle, that the clutch disk is solid (no springs), & the fact that the trans gears are a loose mesh you will get a neutral knock (rattle) .. Some of the early 5 speed Getrag transmissions had “O” rings between the gears & shafts to help stop that neutral rattle but those “O” rings caused shifting problems so on the later 6 speed transmissions those “O” rings were not used.. It’s not just a BMW motorcycle thing either. A lot of modern 4 cylinder manual transmission cars & trucks have neutral gear rattle also..

Should go away as soon as you pull the clutch handle in..

 

Twisty

[smiller]

I wouldn't lose too much sleep over this Dave, could well be normal as per Twisty's explanation. If you are really concerned you can put a few thousand more miles on that last oil change and then send a sample to Blackstone or another oil analysis lab. If the report comes back clean then you can probably rest easy.

[Flyer5]

That was kind of what I was thinking till I saw this post it had me worring about it . It shifts very well, Well it shifts well for a 1100rt anyway . Thanks ,Dave

[Jameseo]

Just to expand on Twisty's comment...

The o-rings were dicontinued after M94s and their function, sound dampening, was replaced with the infamous wave washer.

Anton notes this here:

Largiader.com

And the interview with Getrag is excellent, here:

Getrag interview

The clacking heard when in neutral is exaggerated in my case with the lack of orings, because it is an M97, and my removal of the wave washer. You can see my modified tranny photos here:

http://home.earthlink.net/~james97r1100rt/id22.html

[Mike_A]

I'd like to add my experience to this thread:

 

Last summer, just before setting off on a long trip, I changed the gearbox oil and was dumbfounded by it's chocolate color. I hadn't noticed any change in shifting, additional noise, or other problems. I had never seen this discoloration before. There was just a bit of fuzz on the gearbox drain plug.

 

I had recently done a spline lube. Can't say for sure if I drained the oil before removing the gearbox. But I thought at the time that maybe I'd stirred up some debris while removing/replacing the gearbox.

 

I also wondered if the discoloration was heat-related. June 2006 was very hot!

 

Because I hadn't noticed any change in the shifting, I decided it might be an anomaly caused by the reasons above.

 

I went on vacation---about 6,500 miles round trip, East coast to NM, CO, and Wyoming. The heat was crazy; I used a cooling vest, mesh gear, and so on. The bike ran perfectly.

 

Back home, I changed the oil---it was again discolored, but not as much as the pre-vacation change. Again, no debris on the drain plug worth mentioning, and no obvious change in shifting.

 

I did another oil change at 9,000 after the first chocolate change. Again some discoloration, no debris, no change in shifting.

 

I read this thread, which almost certainly explains the issue. I also sent an oil sample with about 4000 miles from the gearbox to Blackstone Labs. The one notable thing is a slightly high reading for iron: 150 ppm versus universal averages of 102 ppm. Though I wonder how many samples they've analyzed from R1100 5-speed gearboxes?

 

Maybe the wear, being limited to the interference between the helical gear and the inner bearing race, does not create a lot of iron particles.

 

Chromium (bearing degradation?) was 2 ppm, versus the average of 1 ppm.

 

I plan to have this gearbox rebuilt. The splines have looked great at 80,000 miles, so gearbox alignment is presumably good.

 

I wonder how much longer this gearbox would last? The iron in the oil seems not critical (but might not be a good indicator of the point were the damage is happening). If grease is leaking out of the sealed bearing(s), I assume oil can leak in.

 

I won't risk another long trip, but I might commute and take short rides for another 5K or until convenient to send the gearbox out to be rebuilt.

 

That's my data!

 

Mike

[smiller]

I wonder how much longer this gearbox would last?

Very difficult to say... James's rear input shaft bearing was pretty munged up but the transmission was working fine, OTOH Michael suffered a total failure of the bearing. As David suggested earlier this may well be a 100,000+ mile problem for most transmissions so many may never see an actual failure, but I sure don't find the situation comforting and I assume neither do you. We have a few transmissions out there now with the possible cure described in this thread but it will be a while before we know anything for sure.

 

I would continue to do oil samples over time and see what develops. If the numbers spike up then I would go in there...

[Ozrob]

Hi All,

I just want to add some information that may help, first of all I am a GS rider who has been looking at the advrider site where some R97 transmission owners are having the same problem,

I too have been having the same issue back in 2000 (60,000Km), where the 1st gear appeared to chew out the rear bearing, BMW had not seen that issue before and replaced the input shaft with a second hand assembly, well I did the work they just supplied the parts for free which was nice of them, it happened again when the bike had around 160,000 km, so machiened the rear of the gear face to fit a hadened stainless steel 3mm thick washer so that the washer made contact with the bearing and not the gear.

Finally the transmission failed around 220,000Km seized output shaft rear bearing, whiched damaged the rear casing, and worn shifter forks, however the modification to the gear using the washer is still OK.

I thought my issues were from over loading the transmission as I used to tow camper trailers, which I dont any more.

I decided to buy a new transmission from BMW, I run mineral gear oil till the first service then synthetic gear oil untill the last service, I found that the synthetic oil started to discolour at 20,000km of use, and now back to using mineral oil and it is chocolate colour after 5,000km service interval, the next service is due next week, and I bet the mineral oil is again chocolate, now the new transmission has only done 30,000km, and not used for towing (sold the draw bar so I would not be tempted)

Surely the bearings would still be OK with such low milage,

Has anyone got am official explaination from BMW why this is an issue?

Thanks.

[smiller]

Welcome to the forum, and thanks for adding your experiences to the thread.

 

so machiened the rear of the gear face to fit a hadened stainless steel 3mm thick washer so that the washer made contact with the bearing and not the gear.

Yeah, that would be the other way of fixing the problem. We considered that but weren't sure if the washer wouldn't just get pounded to death as well... although a washer would at least spread the force over the entire gear/bearing surfaces, which might help. Plus we just chickened out in that we didn't want to risk changing the relationships of the helical drive gears on the input and intermediate shafts, but then again if you do the machining job well then that shouldn't happen. And FWIW it looks like BMW added such a washer in the 1150 transmission design... I'm sure it was just a coincidence . Anyway, glad that worked out for you and thanks for the info, might be another good way to go at the problem for 1100 owners. Removing the wave washer is simpler, but it does carry one minor downside in that the transmission will make some noise in neutral with the clutch out (due to rattling of the geatsets... the reason the wave washer was installed in the first place.)

 

Has anyone got am official explaination from BMW why this is an issue?

No, nor would I expect one to ever be forthcoming... it just doesn't work that way...

[SageRider]

Ozrob,

Welcome to the board!

Sorry about your tranny woes...

I would not expect your next tranny fluid change to come out chocolate colored. Since it appears that the discoloration is due to a breached bearing seal and thus bearing lube contaminating gear lube, and since you already state that you have drained chocolate on your prior change, there is probably no bearing lube remaining after your prior change.

Also, just to be clear on the gear lube color, the chocolate color is typically a milk chocolate color and appears similar to water contamination without the emulsification.

 

Ne explanation from BMW that I've ever heard of.

[Flyer5]

I posted on another thread wondering about this washer . My manual only shows the M96 trans input shaft so I wasn't sure of where the washer went . Now I know and its time for repairs . How are the modified washers holding up . Any other issues rising with this method we should have some miles on them by now . Thanks ,Dave

[smiller]

There are a few transmissions out there with the mod but I don't think that any have enough miles on them to have been torn down again for an inspection. And in fact if the fix works as anticipated they may not need to be torn down for a long time... or at least we can hope.

[DragonMaster]

Hi Guys,

Just had a read through this thread, I was pointed to it by a post on UKGSers.com, and must say I've found it very interesting. (Er, please excuse my possibly 'quaint' sounding English accent and spelling. It aint quaint really, I'm a Yorkshireman.)

 

I've had a problem with the gearbox on my 1100GS for some time now, about six years in fact. It started as a rumbling at tickover in neutral, and a low speeds. (Maybe it's also there at high speeds, but I can't hear it.) I've done several oil changes in the time it's been happening, during which I've covered about 50k miles. I must say that I haven't taken much notice of the oil colour, but there has been lots of nice shiny metal-flake in the oil, and flaking on the drain plug.

 

The noise has been growing steadily louder, and last year it got to the stage where a new sound was to be heard as the clutch was engaged (Let out?) to take up the drive. Also at high speed cruising with relaxed throttle, when I opened the throttle to accelerate, there was a slight (0.5 sec) lag before the drive was taken up with a very loud 'clunk'. The clunk eventually became enough to feel it, not just hear.

 

I replaced the gearbox (an M97 I believe, itself a replacement for an M93 that I managed to crack the casing on ) in October, with the intention of 'going in to it' to find the problem. After reading this thread, I think I know what I can expect! By the way, when I removed the tranny (I'll use your term! ) there was about 5-6mm of axial movement on the input shaft...

 

It will be a couple of weeks before I get in to it, but I'll report back with what I find. I'll try to remember to take photos as well...)

 

Thanks for the possible 'cure' with the spacer to replace the wave washer; I'd already picked up on this from UKGSers, but this site has given me a bit more explanation of what it's about.

 

Cheers,

 

Dave.

[cwc]

I'm doing some work on an input shaft that has the problem discussed here.

 

We are considering replacing the wave washer with a spacer, but the spacer recommended is 3 mm thick and the space that it goes is 1.4 mm.

 

Measuring the spring rate shows that the additional compression will result in a static force of ~160 kg (350 lb) applied the the rear bearing. That seems like too much.

 

Did those that used the spacer use it at it's full thickness?

[smiller]

We are considering replacing the wave washer with a spacer, but the spacer recommended is 3 mm thick and the space that it goes is 1.4 mm.

 

Measuring the spring rate shows that the additional compression will result in a static force of ~160 kg (350 lb) applied the the rear bearing. That seems like too much.

 

Did those that used the spacer use it at it's full thickness?

Good observation Charlie. The force created by the torque compensator spring is being applied to both front and rear bearings but the geometry of the applied force is such that it shouldn't stress the bearing in any significant way. Whatever force there is (and I'm not sure that it's really 350 lbs. additional, but I haven't computed that myself) would be applied only to the bearing retainers at either end of the shaft (via the inner race) and I'm sure that they're more than up to it (actually the inner race of the bearing is such a tight press-fit on the shaft that I doubt that the bearing retainer clip would even feel it.) Also, the earlier M94 input shaft (without the wave washer) has a fair amount of spring preload and it doesn't seem to bother them. In short I don't feel that it is a significant issue. Too much preload on the spring may affect the range of motion of the torque compensator cam, but again the amount seems to be too small to be of concern.

 

That said, if one is concerned what you can do is simply mill off the lip on the spacer that retains the (now discarded) wave washer (or use a 2mm washer, etc., I just suggested 3mm because the part is available from BMW.) This will retain the torque compensator spring preload at its original value. Note that you do want some amount of preload because the point of the exercise is to prevent the helical gear from coming out of contact with the rear bearing under neutral-throttle conditions, and some preload is required to accomplish this.

[cwc]

Thanks for the reply.

 

I have experience with the airhead output shaft bearing coming adrift in the period where BMW decided that they didn't need a retaining ring to hold it. I was thinking of that when I worried about this oilhead shaft.

 

I think the spring force only acts on the rear bearing. Unless the rear bearing moves. It has a 4 piece retaining system that appears not to be available to buy. photo here http://i179.photobucket.com/albums/w290/fredopatz/DSC06560.jpg

 

The guy doing the rebuild would like to replace these parts if they are available, but can't find the part numbers.

[LDHack]

I just saw this post about chocolate gear oil, and I did not read through all 9 pages. Here's a comment:

 

A friend had the same in his '02 R1150RT - the conclusion was either the input or output seal had failed on the transmission side of the seal. The bearing is bedded in grease at the factory, not lubed by the transmission oil. The bearing is sealed from the transmission oil, and of course sealed to the outside of the transmission. The factory bearing grease from the failed seal mixed with the transmission oil, resulting in the dark color. He's riding with the same failed seal still, and no problems after 20,000 miles or more. His bearing is now lubricated with transmission oil instead of the original factory grease.

[russell_bynum]

Yes, that's the same conclusion that was reached 9 pages ago.

 

[smiller]

Yeah, I wasn't thinking and you're right, rear bearing only.

 

Re: the parts, for some reason BMW seems to sell individual parts for the M94 input shaft but only sells the M97 input shaft as a complete assembly, or so it would seem from all the on-line parts fiche sites. Don't know why this is, but it can make piece parts for the M97 shaft hard to come by. Maybe a dealer has more information... you can try calling Chicago BMW, I have found them to be helpful.

 

FWIW unless there's some extreme wear that isn't visible in the picture I'm not sure why he wants to replace the split keeper... once installed it really isn't going anywhere...

[cwc]

 

FWIW unless there's some extreme wear that isn't visible in the picture I'm not sure why he wants to replace the split keeper... once installed it really isn't going anywhere...

 

There is some wear on both sides of the split ring.

 

It's not for sure that replacement needed, but my past experience shows that no matter how tight the bearing fits on the shaft it's important to be sure that the keeper is snug aginst the bearing so that when the bearing wants to move the keeper is right there to prevent it. I suppose a shim would work if the fit is not right.

[smiller]

Understood. The keeper system is a pretty stout assembly though and I'm not aware of any that have ever failed.

 

BTW after I press on the rear bearing and install the keeper assembly I draw the bearing back against the keeper to ensure there is zero clearance. Since it is under spring pressure this is where the bearing will want to go if it ever moves (it's a rather tight press fit on the shaft, but like you say, you never know...) so I place it there during assembly to ensure that end play remains consistent after the shims are installed.

[Asymmetrical]

I'm going to look at a '97 R1100rt later today - a bike with less than 15k miles. Is there a way to easily take a look at the transmission oil for a chocolate color? Or is this not practical to do in a simple inspection without a bunch of tools and other equipment available to do the job? I'll be going there in a few hours and unfortunately due to a long list of potential buyers, I have to make a fairly quick decision to buy or not, so knowing how to handle this inspection/make this decision is important. Not sure how concerned I should be about this... Input welcome.

[cwc]

BTW after I press on the rear bearing and install the keeper assembly I draw the bearing back against the keeper to ensure there is zero clearance. Since it is under spring pressure this is where the bearing will want to go if it ever moves (it's a rather tight press fit on the shaft, but like you say, you never know...) so I place it there during assembly to ensure that end play remains consistent after the shims are installed.

 

Good plan. It seems unlikely that the bearing is going to move toward the spring.

[schneeman]

i did read all of the 10 pages, but in case i missed it, here is my question :

is there a way to perhaps use the M94 input shaft (or it's parts) to remedy the M97 shaft ?

 

[AndyS]

Hi scheeman,

May I suggest you post this as new thread. This one is well over 5 years old.

You may get a more interested readership if it were a fresh one.

Andy

[schneeman]

thanks AndyS, will do.

[Bill1948]

I have a 99 r1100r with 13,000 miles, changed the trans and final at 12k. Did notice the original dino gear oil had a gray thick coating over the magnet. I changed to Mobil 1 syn 75-90, trans seems noisier in shifting. If I change to Lucas 75-140 would trans shift smoother. I say Lucas because it is easily available. Got me worried with all the feedback on this topic. Thanks.