Final Drive leak at START

[Lowndes]

UPDATE II

 

 

 

It's always sumthin'.

 

 

[LBump]

Were are you on the discovery of the leak ?  

[Scott9999]

On 5/21/2022 at 2:58 PM, Lowndes said:

UPDATE II

 

 

 

It's always sumthin'.

 

 

Hmm, I hope the train's routing didn't take your package through LA or the SF Bay area, or your package may be "delayed" forever, tossed on the side of the tracks with 1000's of other UPS and Amazon packages that the thieves didn't bother to steal. 🙄🤬

[Lowndes]

UPDATE III

 

No, UPS came thru on time, somehow, and delivered the FD.  Then it sat for a week and a half while I was traveling, waiting on parts, and then dealing with the wife's knee replacement last Tuesday evening (everything went well, considering). 

 

Saturday morning I started on the swap and got most of it done plus a few other tidbits by noon Sunday.  Then it was yard chores before the sun went down.  Didn't even get to test ride it yet or aotopsy the crown gear to find out where/how the oil was getting out. 

 

From sitting in the garage all this time there was about three tablespoons of FD oil in the center hub again.  It spilled when I removed the wheel.  It was just clean oil so no dramatic uh-oh shots.

 

The replacement FD had been stored outside judging from the rust inside the hub.  It was full of a red oil that I thought was ATF but wasn't.  The magnet on the drain plug had a very fine black fuzz but no grit or chunks.  There was some water (or galvanic??) corrosion around the outside edges of the alloy hub but not too bad, just cosmetic.  The seller must have used a cutting wheel  to remove the pivot pins from the swingarm.  Seriously.  But thankfully the FD housing was not damaged by the cutting.  I decided to use the entire FD, sensors and all, rather than change out the crown bearing and sensors and deal with all the shimming.

 

The idea of the entire load (the bike, me and any gear) supported by the rear wheel, plus the road bumps, and amplified by the single-side swingarm and short differential moment arm, being transmitted thru these tiny pivot pin "needle bearings" that only have a tiny oscillation that further concentrates the wear, has always botherd me.  Anyway I ordered a set of Nushings (https://nushings.com/#/) to replace the needle bearings.  Fingers crossed.  There was another alternative with plain bearings and a zerk fitting for lube but couldn't find them, something about "emerald" bearings if I remember correctly.

 

The hardest part was removing the outer pivot bearing races from the FD housing.  I spent an hour going thru all the washers at Lowes with a caliper trying to find the exact size to fit the inside exposed edge to push against.  Ended up with a 1-3/16 socket from my tool box that fit perfectly.  A 3/8" dia X 8" long carriage bolt with assorted washers, sockets and nuts worked very well to push out the old races and push in the Nushings.

 

I'll do the autopsy next.

 

 

 

  

 

 

 

Half way out:

 

 

The black fuzz:

 

Tiny needle bearings:

 

 

All back together....well, except for the lost tag and leaking RMS.

 

 

 

 

 

 

 

 

 

[Brodiepunker18]

Glad to hear it’s back together! Hopefully you can get some riding in soon!

[Lowndes]

Update IV - The Autopsy

 

Well, "you just can't make this stuff up", as Jeff Foxworthy would say.

 

Came rushing home to get at this leaking Final Drive this evening for the autopsy.  Got the table out with fresh paper on top, all the wrenches, a roll of paper towels, and black latex gloves.  Removed the ABS and speedo sensors and the few drops of oil left in the bottom, set it up on edge and loosened all 8 bolts, laid it down and carefully worked the steel cover and crown gear up and free of the alloy housing.  It was a little more complicated in there than I imagined with gussets and ribs everywhere, but it was very clean and new-looking.  Took a few pics and thought about it, decided to put a small amount of oil in the groove between the alloy thimble and the crown gearteeth , maybe let it sit overnight to see where it's coming out on the other side.  Poured a very small amount of 90wt and watched it for a few minutes and realized that some 0w-20 would show up sooner, so I carefully wiped up the 90wt with a finger in a paper towel.   While wiping it very clean and as dry as possible and watching very closely I began to feel kinda dizzy or something.  I don't think it's supposed to be like that, is it??  Dirtrider always says these R11S bikes are "different", but...

 

https://photos.google.com/album/AF1QipPOm0hsrQh5-xN-EqXakk2Axf76Erv2gpAgBmRR/photo/AF1QipNezHihMJ0ohpHCY7vh2-hAOyZ-vuUduZ_qa8Gj

 

 

More here:  https://photos.app.goo.gl/TrpCcgYXJ3Mnf7uB8

[LBump]

The arrow is pointing to a gapped dimension... is this the same dimension around the entire ring ? (is it a race I'm looking at?)  

[dirtrider]

7 hours ago, LBump said:

The arrow is pointing to a gapped dimension... is this the same dimension around the entire ring ? (is it a race I'm looking at?)  

 

Morning  LBump

 

That is the R/H side bearing race, that side has a closed-end casting so that side can't leak. 

[dirtrider]

8 hours ago, Lowndes said:

Update IV - The Autopsy

 

Well, "you just can't make this stuff up", as Jeff Foxworthy would say.

 

Came rushing home to get at this leaking Final Drive this evening for the autopsy.  Got the table out with fresh paper on top, all the wrenches, a roll of paper towels, and black latex gloves.  Removed the ABS and speedo sensors and the few drops of oil left in the bottom, set it up on edge and loosened all 8 bolts, laid it down and carefully worked the steel cover and crown gear up and free of the alloy housing.  It was a little more complicated in there than I imagined with gussets and ribs everywhere, but it was very clean and new-looking.  Took a few pics and thought about it, decided to put a small amount of oil in the groove between the alloy thimble and the crown gearteeth , maybe let it sit overnight to see where it's coming out on the other side.  Poured a very small amount of 90wt and watched it for a few minutes and realized that some 0w-20 would show up sooner, so I carefully wiped up the 90wt with a finger in a paper towel.   While wiping it very clean and as dry as possible and watching very closely I began to feel kinda dizzy or something.  I don't think it's supposed to be like that, is it??  Dirtrider always says these R11S bikes are "different", but...

 

Morning Lowndes

 

Clean the ring/spool up best possible, then put the spool on the table with wheel side up, then fill the center cavity with red ATF, then allow to sit & see where the red ATF comes out the bottom side.

[Lowndes]

Morning, Dirtrider,

 

The alloy "spool" moves so well in the crown gear it feels like it is a purpose-made bearing.  There is about a 3 thou movement in the axial (the clunk, clunk in the vid) and zero radial.  The rotation feels extremely smoothe.  No evedence of any sealer used on the inside face.  In the up direction in the pics, the upper "stop" is not as sharp (seems to be a "wedge stop"} as the bottom stop which is a very smoothe flat stop.  

 

I'm pretty sure BMW doesn't want to see this 23 year old FD.  Is there any reason to not use the hammer and wood dowel to see if it comes apart??

[dirtrider]

15 minutes ago, Lowndes said:

Morning, Dirtrider,

 

The alloy "spool" moves so well in the crown gear it feels like it is a purpose-made bearing.  There is about a 3 thou movement in the axial (the clunk, clunk in the vid) and zero radial.  The rotation feels extremely smoothe.  No evedence of any sealer used on the inside face.  In the up direction in the pics, the upper "stop" is not as sharp (seems to be a "wedge stop"} as the bottom stop which is a very smoothe flat stop.  

 

I'm pretty sure BMW doesn't want to see this 23 year old FD.  Is there any reason to not use the hammer and wood dowel to see if it comes apart??

Morning Lowndes

 

OK, I finally watched your video (didn't want to run an unknown video on my work computer). I'm surprised that motorcycle even moved under it's own power.

 

You can try to press or drive the ring gear off the spool. Or possibly even just slam the spool down with force on a hard surface & allow momentum to possibly unseat that ring gear.

[Lowndes]

22 hours ago, dirtrider said:

Morning Lowndes

 

... I'm surprised that motorcycle even moved under it's own power.

 

You can try to press or drive the ring gear off the spool. Or possibly even just slam the spool down with force on a hard surface & allow momentum to possibly unseat that ring gear.

 

Dirtrider, 

 

I don't think the power travels thru the spool, it's just there for the support/alignment of the gearset and wheel.  

 

I tried your suggestion of the wood dowel (with a 16 oz Plumb framing hammer) and the spool came right out.  There is a 25mm shoulder but only 3mm of contact between the spool and crown gear.    22mm of the spool shoulder was turned down just enough for a slip fit.  See pics.

 

When I inserted the spool backwards into the crown gear it slipped in easily and bottomed out without even twisting.  Last 2 pics.  There was no evidence of any sealer in this joint.  It relied on a 3mm wide alloy interference fit for a seal, which worked until the 3mm worked itself loose.  It couldn't get much looser in the 25mm tube and can't extend or compress because of the outboard bearing and shoulder in the crown gear.  Your idea of the freeze plug would have worked very well except that I would not have trusted it not knowing all this.

 

I believe this FD would be slavageable with a little work.

 

THANK YOU for all of your help on this!!

 

All the pics here:  https://photos.app.goo.gl/1fpNDvz3oVcUZxRZ7

 

  

 

 

 

 

 

 

[Mike279]

After seeing how the spool spun pretty freely in that bore.  I am pretty sure that 22mm area was suppose to be the press fit area   I am not sure there is a good repair that can be done easily.   Since you sourced a good used part I would probably not invest much time or money in trying to repair the old one.  Interesting failure that you have there and one not often seen.  I have to wonder if the parts were made out of tolerance or some other factor came into play. 

[dirtrider]

25 minutes ago, Mike279 said:

After seeing how the spool spun pretty freely in that bore.  I am pretty sure that 22mm area was suppose to be the press fit area   I am not sure there is a good repair that can be done easily.   Since you sourced a good used part I would probably not invest much time or money in trying to repair the old one.  Interesting failure that you have there and one not often seen.  I have to wonder if the parts were made out of tolerance or some other factor came into play. 

Morning Mike

 

I have seen a few leak in that area over the years, mainly 1100/1150RT's.

 

While I haven't pressed one apart yet to view the damage area,  or see what possibly caused the damage  (thanks  Lowndes for doing this) I was sort of assuming that at some time someone had screwed a wheel bolt (or some sort of  fixturing bolt) in too far therefore forcing that R/H spool side out enough to break the bond.

 

In viewing Lowndes pictures I still don't see any witness marks proving that theory but I suppose it is possible for someone to have used an impact wrench at one time to run in lubricated or anti-seized coated  lug bolts at high speed with the last one in producing a hydraulic or pneumatic force on that far side spool half. 

[LBump]

So Lowndes, will you be rebuilding?

[wbw6cos]

It will become a Craigslist find of the Day when he is finished.  Just sayin'

[Lowndes]

4 hours ago, LBump said:

So Lowndes, will you be rebuilding?

LBump,

Not right now, too much going on.  If this used FD develops any issues I might.  I would want to pin that spool so that it could not turn, and somehow fill the tiny gap in the turned area on the spool.  Maybe a low-mod low-visc 100% solids epoxy to act as the oil seal and anti-wobble gap filler.  I'd also replace the large diameter (4.25"OD or "85X120X18") ball bearing in the hub just in case.  I think there was an upgrade from a 7 to an 8 ball race, or something like that.  But I'll keep it anyway.

 

 

 

7 hours ago, dirtrider said:

Morning Mike

 

I have seen a few leak in that area over the years, mainly 1100/1150RT's.

 

..... I was sort of assuming that at some time someone had screwed a wheel bolt (or some sort of  fixturing bolt) in too far therefore forcing that R/H spool side out enough to break the bond.

 

In viewing Lowndes pictures I still don't see any witness marks proving that theory but I suppose it is possible for someone to have used an impact wrench at one time to run in lubricated or anti-seized coated  lug bolts at high speed with the last one in producing a hydraulic or pneumatic force on that far side spool half. 

 

Dirtrider,

 

Zero marks on the face of the spool where any lugbolts would unseat it.  Also, all of the lugbolt holes vent to the inside opening so no possible "hydraulic or pneumatic" pressures.  It would be possible with the longer 1150 lugbolts if there was a mixup.  Then there are two smaller threaded holes (for holding a spacer, maybe??) between the lugbolt holes so that might be an even more remote possibility, but again, no marks.  The bike only has 27,578 mi.  My feeling is that this is "just one of those things", kinda like the "splines".  

 

It seems that this model (R1100S) was a test bed for the 1150 with the six speed trans, hydraulic clutch and many other "improvements" with many details worked out in production and "the field" before the 1150 models came out, and I'm ok with that.

 

 

 

Boxflier gave me these bolts at Sparta FART with the warning they might be longer than the 1100 lugbolts.  A mixup here would definitely cause problems.

 

 

 

[Lowndes]

UPDATE:

 

Saturday, July 2, partially recovered from the Un, I decided to try a rebuild on the FD.  It would require an arbor press and I've always wanted one so that sealed the deal.  Found a crappy one-ton at HF for $69 that had enought throat and height for the FD stack including a steel nut and washer on top to push directly on the end of the alloy spool.  The roller bearing is about 3/32" proud and don't want to take a chance on damaging it.

 

 

The plan was to re-seat the spool in the crown gear with a sealant/epoxy (without a pin, altho one could easily be installed later).  After some thinking I decided the sealant/epoxy should be 100% solids (no shrinkage gaps), medium viscosity (not runny and not stiff), high modulus, slow set to allow time for pressing the spool back in, and as hight compressive strength rating as possible.   The standard "Original Cold Weld Formula" J-B Weld with "steel reinforcement" seemed to tick all the boxes.  One unknown was the size of the steel particles in the mix and if they would allow close enough seating.

 

I measured a sample of the black part of the J-B with the "steel reinforcement" with a caliper.  0.03mm is the max reading I got.  See pic.  The white part is as smoothe as hand lotion.  Mixing the two should provide plenty of room to prevent stacking of the steel particles.  The shims for the outboard bearing come in 0.05mm increments so hopefully the 0.03mm will not overload the bearing too much, especially with 27K miles on it.

 

 

Two washings with brake-cleaner and a final scrub with laquer thinner got the spool and crown gear mating surfaces clean and oil-free to a "white glove test".  

 

I found what I think is the original alignment of the spool-CG fit and marked it with a pencil to make it easy to find with the epoxy and steel "reinforcement" applied.

 

 

The epoxy was eyeball measured into two little equal piles in a plastic cup.  J-B says 1:1 by volume.  A weight measure with my drug-paraphenalia scale wouldn't work because of the steel powder added to the black side.

 

After a very thorough mixing, turn the plastic cup over to see just how well you did, then keep mixing.  

 

 

Applied a thin coating of J-B on all mating surfaces of the CG and spool, just like glueing wood furniture, aligned the pencil marks, set the nut and washer on top and carefully loaded the stack in the press.  

 

  

 

After a few tries with the press handle extended all the way out and with the handle aligned at 90° to the arbor it just would not go.  A cheater bar on the handle just wanted to tip over the press so a second cheater bar of 1.5" sched 40 PVC pipe was found to counter the torque on the press.  Thank goodness for the 4-6 hours J-B set time.  With a few magic words and a clunk the spool then went home.

 

 

There wasn't much "squeeze" showing anywhere, even in the lugbolt holes, but those needed to be cleared to prevent the lugbolts from pushing the spool out again.  After the J-B had set enough to become soft (plastic) and non-tacky, a very small screwdriver and a gem-clip hook cleared the holes.  I'll carefully chase the threads with a bottom tap once the epoxy is cured.  The rest of the squeeze can just remain.

 

I let it sit and set for 24 hrs in the 90° heat outside to cure thoroughly.  

 

 

The steel grit ("reinforcement") in the mix will provide a lot of friction between the CG and spool, even after the epoxy has set, as evidence the force necessary to seat the spool.  I doubt that a pin would be neceassary to prevent movement between the spool and CG as the only torque on the spool is the rolling resistance of the outboard roller bearing.   If that bearing were to fail the torque would increase greatly on this joint but it cant go anywhere, just rotate and would just leak again.

 

Cleaned everything carefully again, coated the bearings and gear teeth with a light coating of grease, torqued all eight housing bolts to 35Nm, installed the ABS and speedo sensors, replaced the plastic vent cap, and replaced copper seals on the drain and fill plugs and screwed them half way in.  Put the whole thing in a plastic bag with a note about the repair, the bike and mileage, and put it all in a box with the extra lug bolts, pivot bearings and pins, boot and tie-wrap and put that on the shelf to wait for the next misadventure.

 

All pics here:  https://photos.app.goo.gl/rn3pQySVyTUWaDpR8

 

I'm really tempted to put it back on the bike as a test of this repair. 

 

I think it will work.

 

Any bets??

 

 

 

 

 

 

 

[Lowndes]

Another UPDATE:

 

Several weeks back I just couldn't help myself and put the original and "repaired" FD back on the bike just to see if the JB Weld repair would work.  Did a few short rides and everything looked good.  Yesterday (Saturday) several of us decided to take a day ride up across N GA to Blairsville and back by fun roads.  At 200 miles and Slumgullion said it looked like something leaking again down there.  Sure enough, got home, parked it on the side stand and Bloop.  Same leak as before, coming from the center lug bolt hole.

 

I was medium confident the JB Weld would hold it.  It took so much force to seat it and the JB set hard as a queball so I thought it had to be good.  The bike only has 28K total on it.

 

I'm thinking there must be more to this.  

 

1.  The FD oil softened the epoxy??  No sign of that from the hardened pieces in the hub.

 

2. The main (big) wheel bearing may have too much wear/wobble putting more load on the outboard bearing??  I'll have to dissect the FD to find out.

 

3.  Incorrect shimms on the axle bearings from the factory??  #'s 2 & 4 below:

 

 

4. Another issue??

 

Any ideas??

 

 

I got the used FD reinstalled today so have some time to work on it.

[dirtrider]

29 minutes ago, Lowndes said:

Another UPDATE:

 

Several weeks back I just couldn't help myself and put the original and "repaired" FD back on the bike just to see if the JB Weld repair would work.  Did a few short rides and everything looked good.  Yesterday (Saturday) several of us decided to take a day ride up across N GA to Blairsville and back by fun roads.  At 200 miles and Slumgullion said it looked like something leaking again down there.  Sure enough, got home, parked it on the side stand and Bloop.  Same leak as before, coming from the center lug bolt hole.

 

I was medium confident the JB Weld would hold it.  It took so much force to seat it and the JB set hard as a queball so I thought it had to be good.  The bike only has 28K total on it.

 

I'm thinking there must be more to this.  

 

1.  The FD oil softened the epoxy??  No sign of that from the hardened pieces in the hub.

 

2. The main (big) wheel bearing may have too much wear/wobble putting more load on the outboard bearing??  I'll have to dissect the FD to find out.

 

3.  Incorrect shimms on the axle bearings from the factory??  #'s 2 & 4 below:

 

4. Another issue??

 

Any ideas??

 

I got the used FD reinstalled today so have some time to work on it.

Morning Lowndes

 

Due to the single sided swing arm there is high bending load on that joint. Personally I wouldn't have used Epoxy for that type of joint as that type of fit is not Epoxies strong suit.

 

If anything will hold it will probably one of the LockTite green retaining compounds (like 620 or 680) & even that could be iffy due to the heat expansion difference between the gear hub & that thinner cone  as the drive heats up. Due to the dissimilar metal interface I would definitely use the proper LocTite  Activator to go with the LocTite retaining compound used. 

 

 

[Lowndes]

THANKS, Dirtrider.

 

Getting the spool off, or out of the crown gear may be more difficult now.  The fine steel grit in the JBW I thought would fill the gap and provide the interference and friction resistance between the spool and crown gear with the hi-mod epoyy just holding the grit in place and providing a filler in the gaps.  I sold industrial epoxies for a long time and have a "working understanding" of the amines and amids.  But, I'm inclined to believe there are "other factors in play" here and your freeze plug idea is gaining popularity.

 

 

[Mike279]

I would think if it's leaking the epoxy failed somehow and disassembly will be easy.  If it is hard to get apart some heat will soften JB weld(I saw it rated to 550 degrees) . That may give you a better idea of how it failed.  One question comes to mind though If you sold industrial epoxies why did you pick JB weld?  

[Lowndes]

On 8/15/2022 at 12:43 PM, Mike279 said:

I would think if it's leaking the epoxy failed somehow and disassembly will be easy.  If it is hard to get apart some heat will soften JB weld(I saw it rated to 550 degrees) . That may give you a better idea of how it failed.  One question comes to mind though If you sold industrial epoxies why did you pick JB weld?  

Mike279,

 

"Sold", as in past tense.  I don't sell them now if that's what you mean.  None of the epoxies I sold had all the properties this FD repair needed and JBW did.  It wasn't expensive either.

 

I thought about several of the newer brands I've seen or sold, still have some around here, but the JB with the steel "reinforcement" (actually its an "aggregate" in this concentration and shape), good compressive strength, hi-mod, zero shrinkage, heat tolerance, plus a long working time to get it applied and assembled - which took 30 min, it seemed just about right for this job.  JB has always had a good reputation, AFAIK.  

[9Mary7]

7 hours ago, Lowndes said:

JB has always had a good reputation, AFAIK.  

Holds roadrace bikes together in a pinch as well.......DAMHIK

[Mike279]

First thoughts were the parts were press fitted.  Second thought was shrink fitted.  I have made quite a few parts that have to be shrink fitted with a specific amount of interference to work properly.  One part being heated and the other cooled to get them together.  That said, I have not encountered aluminum specified in steel. Further reading says the failure rate would be high if you used aluminum in steel.  Differing expansion rates would cause issues if heated.  Seems this part could have been made with a interference fit and that may be part of the issue. Heating the drive would cause the different expansion rates to work against each other.  The steel hub would squeeze the aluminum which then would deform and become loose when cooled.  How much heat is too much?  How well did BMW figure the fit?  How many failures?  I know more questions than answers.  I do like the JB weld products and found them to work well.  Was just curious if there were other epoxies that I should be considering.  

[Lowndes]

It is definitely a press fit, or WAS.  There was zero play between the two when it first started leaking, only rotation.  VERY smooth rotation, and the shoulder (shoulders on male and female) had the spool captured (could not be pulled apart - had to hammer it out).  Something caused the press fit to loosen enough to leak.  It gets warm while riding but not really hot.  Maybe the outboard tapered roller bearing didn't have enough preload??

 

I'm thinking the FD bearings were not shimmed correctly from the factory.

 

Someone suggested asking BMW NA for advice on this.  Anyone have experience with them??