Clutch and input shaft spline - need advice please

2dflier · Nov 1, 2015

nrpetersen said:
My contention is that it never recenters. If there was an initial misalignment, that misalignment will reappear and the resulting shear force across the spline will be present every engine revolution. The spline shear force vector will be stationary, as the spline rotates. If I was to build a spline wear fatigue test system (my pre-retirement job) I would use a rotating spline set and radial misalignment control.
Again - it never recenters except for the trivial case where the clutch is disengaged.

I guess old threads will remain alive so long as people new to the problem try to understand what's happening and why, and how best to repair. This thread and post in particular is especially insightful.

I've got a couple of questions and observations and would appreciate some internet wisdom.

My case is an '04 RT @ 95K miles. It developed a neutral input rattle at about 70K and the last couple of hundred miles it was making some kind of grinding noise while going down the road. So out came the trans.

The clutch still has about 2mm of wear left but the splines are all but gone. So it was just a matter of time. I've had the bike since 62K but in the repair history - such that it is - or trans removal there's no indication the splines have ever been lubed.

Going into it my main question was whether or not I could just replace the friction disk or does the pressure plate and housing cover also need to be replaced. Having measured all three components it's pretty clear they need to be replaced as a set. The pressure plate is worn about 0.2mm more on the ID than the OD. The clutch housing about 0.4mm more.

My question is does anyone understand why the plates wear more on the ID and disk more on the OD? I can not come up with any reason why.

The offset between engine and trans is interesting. Including also TIR, the crank and trans input essentially rotate about fixed centers. The friction disk floats to accommodate any radial offset between the two. In a perfect world there's no radial offset or angular misalignment between the two and the forces acting on the splines and friction disk are related to torsional loads.

If I understand the real world correctly the radial offset results in a spline load radial vector in the opposite direction of the offset with a magnitude related to the normal force and coefficient of friction between disk and plates. The greater the radial offset the higher the wear rate. With each rotation the disk and plates move radially relative to each other twice the offset distance (max + radial distance at 0 degree rotation to offset, aligned at 90 deg rotation to offset, max - radial distance at 180 degree rotation from offset, aligned again at 270 degree rotation from offset, back to 0).

So with each crank rotation the disk and plates move twice the radial offset distance to each other. If wear is related to heat, then the greater the offset the more heat will be generated. Whether the offset is 0.1mm or 1.0 mm the disk and plates have to move twice the total distance per revolution. So the greater the offset the faster the average relative surface speed (and acceleration/peak surface speed) between the two to cover the total distance per rotation. Heat is related to surface sliding speed and friction.

So if all this is correct, the choice of friction material is also important. I assume Sachs matches the plate and disk material to optimize wear life. So what happens if you use a more aggressive friction material? Seems like you'd increase plate wear and spline radial spline forces - ie spline wear would also increase. For this reason I think I'll replace with the OEM disk unless someone knows better.

The thing I also wonder about is whether the total offset (radial plus TIR) can be estimated from the pressure plate and housing cover wear. The pressure plate looks to be about 1.0 mm larger diameter than the disk. In my case the pressure plate is worn to the edge. On the housing cover the heat zone is about the same diameter as the disk but the wear zone diameter is about 2 mm greater. Does this give some indication of the total radial relative motion?

So this is how I can makes sense of this. Right or wrong I don't know. Thoughts?

nrpetersen · Nov 1, 2015

2dflier said:
I guess old threads will remain alive so long as people new to the problem try to understand what's happening and why, and how best to repair. This thread and post in particular is especially insightful.

I've got a couple of questions and observations and would appreciate some internet wisdom.

My case is an '04 RT @ 95K miles. It developed a neutral input rattle at about 70K and the last couple of hundred miles it was making some kind of grinding noise while going down the road. So out came the trans.

The clutch still has about 2mm of wear left but the splines are all but gone. So it was just a matter of time. I've had the bike since 62K but in the repair history - such that it is - or trans removal there's no indication the splines have ever been lubed.

Going into it my main question was whether or not I could just replace the friction disk or does the pressure plate and housing cover also need to be replaced. Having measured all three components it's pretty clear they need to be replaced as a set. The pressure plate is worn about 0.2mm more on the ID than the OD. The clutch housing about 0.4mm more.

My question is does anyone understand why the plates wear more on the ID and disk more on the OD? I can not come up with any reason why.

The offset between engine and trans is interesting. Including also TIR, the crank and trans input essentially rotate about fixed centers. The friction disk floats to accommodate any radial offset between the two. In a perfect world there's no radial offset or angular misalignment between the two and the forces acting on the splines and friction disk are related to torsional loads.

If I understand the real world correctly the radial offset results in a spline load radial vector in the opposite direction of the offset with a magnitude related to the normal force and coefficient of friction between disk and plates. The greater the radial offset the higher the wear rate. With each rotation the disk and plates move radially relative to each other twice the offset distance (max + radial distance at 0 degree rotation to offset, aligned at 90 deg rotation to offset, max - radial distance at 180 degree rotation from offset, aligned again at 270 degree rotation from offset, back to 0).

So with each crank rotation the disk and plates move twice the radial offset distance to each other. If wear is related to heat, then the greater the offset the more heat will be generated. Whether the offset is 0.1mm or 1.0 mm the disk and plates have to move twice the total distance per revolution. So the greater the offset the faster the average relative surface speed (and acceleration/peak surface speed) between the two to cover the total distance per rotation. Heat is related to surface sliding speed and friction.

So if all this is correct, the choice of friction material is also important. I assume Sachs matches the plate and disk material to optimize wear life. So what happens if you use a more aggressive friction material? Seems like you'd increase plate wear and spline radial spline forces - ie spline wear would also increase. For this reason I think I'll replace with the OEM disk unless someone knows better.

The thing I also wonder about is whether the total offset (radial plus TIR) can be estimated from the pressure plate and housing cover wear. The pressure plate looks to be about 1.0 mm larger diameter than the disk. In my case the pressure plate is worn to the edge. On the housing cover the heat zone is about the same diameter as the disk but the wear zone diameter is about 2 mm greater. Does this give some indication of the total radial relative motion?

So this is how I can makes sense of this. Right or wrong I don't know. Thoughts?

You have it described it correctly. Others may disagree though. A couple of points:

The reason there is differential face wear on the clutch disk vs the plates is that if one surface somehow wears, the other also wears - but not necessarily the same amount. But the combined wear will be identical at the two locations. This is what is meant by being conjugal wear. However the wear profile vs disk or plate operating radius can vary from this due to the compliance of the elements. And obviously the relative velocity of the worn parts will depend on the operating radius.

The same thing is gradually happening at the spline, only after a while there are no further teeth left at the shaft tip and the remaining spline teeth nearest the transmission have to carry the torque-induced load. This is what has given the greater shaft tooth wear closest to the transmission. A lot of others have locked onto this as evidence of angular misalignment, but it is really differential hardness causing differential wear profiles on the clutch disk hub vs shaft.

Note - This has not been proven by hardness measurements but it is the only consistent explanation.

I don't think the heat affected zone profile on the clutch plates can be used to determine the engine-transmission offset. At the mileage you have, this consistent radial load between the engine and the transmission will probably cause wear of the rear engine main bearing shell. The transmission bearing is a ball bearing and less likely to wear loose (I wouldn't bet on it though). But in the couple of examples I have seen, the flywheel was noticeably loose when gently pried radially in different directions with a screwdriver. The direction of the bearing wear was consistent with the observed engine transmission misalignment.

Last spring SpaffyPD on the Pelican parts forum did make and describe the alignment measurements with a test rig I had made earlier. Right now that test rig is in Vancouver WA waiting to be mailed the next poor soul to experience a spline strip out.

Another similar spline thread is at:

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=703209&page=3

2dflier · Nov 1, 2015

nrpetersen said:
You have it described it correctly. Others may disagree though. A couple of points:

... in the couple of examples I have seen, the flywheel was noticeably loose when gently pried radially in different directions with a screwdriver. The direction of the bearing wear was consistent with the observed engine transmission misalignment.

Another similar spline thread is at:

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=703209&page=3

Many thanks NRP. It will be (quite) a few more daze till I get the trans back so I'll play with measuring the rear bearing clearance. Is this something you do nothing about until the rear seal leaks or are there other symptoms that require attention? I can live with this if it only happens every dozen years or so.

nrpetersen · Nov 1, 2015

Ideally you would replace the rear engine main bearing shell as that bearing intercepts the piston forces. Otherwise, as the rear bearing wears, the spline gets hammered around as it carries the loads back to the transmission input bearing. But nobody has ever done this much of a repair that I know of & very possibly there isn't much benefit to doing so. The transmission input bearing will radially be much stiffer than the the rear crank main bearing. What's more, you will find the rear main bearing to be worn egg shaped only in a particular direction a few thousands (of an inch). As I recall, the very few that have measured the direction of rear bearing wear have all (like maybe 3 or so) found the axis of the transmission to be below and slightly to the left of the engines original axis. SpaffyPD documented this well. But really the only reason to check this crank looseness is 1) it is very easy to do once the dial indicator is set up, and 2) we have figured this slightly changed engine rotation offset in calculating the offset of any new alignment pins.

You can very likely feel the flywheel clunk-clunk motion with your finger just by prying the flywheel with a screwdriver. It will seem enormous, but when measured with a dial indicator it is probably only going to be a few thou again.

I have a setup and method on my old lathe (1938 same as me) that I can quickly make up a new set of alignment pins with a correcting offset. I'm retired & do this N/C as you guys having to rebuild the rest of the spline system have already put up more than enough $$$$$ elsewhere.

I gather that you are already replacing the transmission input shaft? If it is done correctly you won't be able to measure any clearance in the input bearings.

2dflier · Nov 1, 2015

nrpetersen said:
Ideally you would replace the rear engine main bearing shell... But really the only reason to check this crank looseness is 1) it is very easy to do once the dial indicator is set up,

I gather that you are already replacing the transmission input shaft? If it is done correctly you won't be able to measure any clearance in the input bearings.

Offset alignment pins? Awfully decent thing for you to do. I'm interested in measuring the clearance but am content to let it go. It might be part of a subtle knocking sound I've been hearing for the past 20K so I would like to know if it is worn.

The trans is at a local shop for repair. The splines are worn so for sure the input shaft needs replacing. I imagine seals and bearings, at least on the input shaft. Hopefully the damage isn't any more extensive than this.

roger 04 rt · Nov 2, 2015

Hi 2dflier, too bad about your transmission and input shaft. Sounds like you're going to make a good repair. Although nrpetersen makes a good case for the failure being caused by radial misalignment, there is very little actual conclusive data. The last bike measured had almost as much rear main bearing slop as the amount of measured radial misalignment. I believe the net error was only 0.004". And I'm not aware of any data take from bikes which haven't had a hub/spline failure. One thing we know for sure is that all bikes have some radial misalignment since nothing is perfect. The question is, what is typical?

There are two other theories of failure: clutch pack errors and input shaft/clutch hub insertion depth. Anton Largiader, who is a respected member here, and who makes his living repairing Oilhead transmissions and BMW motorcycles in general, replaces the input shaft and entire clutch package. He measured some bikes for radial offset but says his data was inconclusive. However after replacing the input shaft and clutch package has had no repeat failures.

If you look here and on advrider for posts by GS Addict and Cele0001, you will find extensive information on increasing the depth of hub/spline engagement. I'm aware of three bikes, which had multiple hub/spline failures, that have reported no wear (after tens of thousands of miles) following an insertion depth increase. For a colorful analysis of this look for Chris Harris videos on YouTube. Also here: http://forums.bmwmoa.org/showthread.php?71766-tranny-input-shaft/page14.
RB

2dflier · Nov 2, 2015

roger 04 rt said:
Hi 2dflier, too bad about your transmission and input shaft. Sounds like you're going to make a good repair. Although nrpetersen makes a good case for the failure being caused by radial misalignment, there is very little actual conclusive data. The last bike measured had almost as much rear main bearing slop as the amount of measured radial misalignment. I believe the net error was only 0.004". And I'm not aware of any data take from bikes which haven't had a hub/spline failure. One thing we know for sure is that all bikes have some radial misalignment since nothing is perfect. The question is, what is typical?

There are two other theories of failure: clutch pack errors and input shaft/clutch hub insertion depth. Anton Largiader, who is a respected member here, and who makes his living repairing Oilhead transmissions and BMW motorcycles in general, replaces the input shaft and entire clutch package. He measured some bikes for radial offset but says his data was inconclusive. However after replacing the input shaft and clutch package has had no repeat failures.

If you look here and on advrider for posts by GS Addict and Cele0001, you will find extensive information on increasing the depth of hub/spline engagement. I'm aware of three bikes, which had multiple hub/spline failures, that have reported no wear (after tens of thousands of miles) following an insertion depth increase. For a colorful analysis of this look for Chris Harris videos on YouTube. Also here: http://forums.bmwmoa.org/showthread.php?71766-tranny-input-shaft/page14.
RB

Thank you. Misery does love company. One thing you gotta love about these bikes is the opportunity to learn stuff you might not otherwise know. I'm just not sure how much I want to know. But you really never do learn more about something as you do when trying to figure out why it breaks. The whole thing works as a system with sensitivities. Too many things stack up one direction and you fall off the edge.

Full spline engagement makes sense for a lot of reasons. So maybe it's a key contributor. But I find it a bit frustrating that BMW wouldn't just change the hub to fix it. If BMW is like other German companies I work with, they take a bit of convincing. But once they're convinced of a problem they will get it fixed. I'd hope they'd be convinced by now.

I feel relatively fortunate as my particular situation is much better than some of the horror stories out there. I've read some of the back and forth on the issue (and colorful commentary) and good arguments for various theories / contributors aren't hard to find.

Is the clutch pack errors you refer to basically flywheel/clutch not rotating on the crank axis?

Dinner bell rings but I wanted to post this image trying to depict relative motion between clutch disk and pressure plates in a radially misaligned system. The .ppt works better to animate if anyone is interested. But it tracks two coincident points at 0 deg - one on the disk the other on the pressure plate as the crank and trans input rotate about their centers/

roger 04 rt · Nov 2, 2015

Interesting simulation. I read a good paper a couple years ago on tooth contact forces in splined hubs with radial misalignment. Their first point was that the tighter the fit, the less the problem--think about it. Their second point was that with radial offset and a non-tight fit, fewer teeth carry the load--all the load is on one tooth perpendicular to the offset.

Now take that model and try to picture the clutch disk web deformation with a non-tight fit and an offset, in a not fully inserted shaft/hub connection. There is an angular deflecting force on the hub/web.

nrpetersen · Nov 2, 2015

roger 04 rt said:
Interesting simulation. I read a good paper a couple years ago on tooth contact forces in splined hubs with radial misalignment. Their first point was that the tighter the fit, the less the problem--think about it. Their second point was that with radial offset and a non-tight fit, fewer teeth carry the load--all the load is on one tooth perpendicular to the offset.

Now take that model and try to picture the clutch disk web deformation with a non-tight fit and an offset, in a not fully inserted shaft/hub connection. There is an angular deflecting force on the hub/web.

How did the paper's author suggest accommodating a misalignment without clearance in the spline? If he had a tight spline with more radial misalignment than tooth-to-tooth radial clearance (probably our failure cases), the only accommodation is by bending some very stiff shaft and housing systems. Eventually the rear engine bearing wears well beyond its .002" service limit.

I'm not a fan of Cele001's hub spacer as I see it as a 20% solution to a much more serious problem. If anything, a spacer should be created that moves the entire flywheel and clutch pack 6 mm closer to the transmission so that any interfacing radial loads applied by the clutch web are closer to the transmission's spline axial center.

Another revelation is that the alignment pins are very short (.78 inches) X .533 inches OD. Is it possible that if the clutch pack has been initially poorly aligned, that the pins are cocking and coining the aluminum housings at the time the engine transmission bolts are tightened dragging the clutch disk across the flywheel?

Confusing all this is we have many bikes that present no spline service difficulties.

2dflier · Nov 3, 2015

roger 04 rt said:
Interesting simulation. I read a good paper a couple years ago on tooth contact forces in splined hubs with radial misalignment. Their first point was that the tighter the fit, the less the problem--think about it. Their second point was that with radial offset and a non-tight fit, fewer teeth carry the load--all the load is on one tooth perpendicular to the offset.

Now take that model and try to picture the clutch disk web deformation with a non-tight fit and an offset, in a not fully inserted shaft/hub connection. There is an angular deflecting force on the hub/web.

Tight spline and more engagement should make for lower contact stress and less relative sliding motion/wear between male/female splines? My head is starting to hurt. Too many moving parts.

nrpetersen said:
How did the paper's author suggest accommodating a misalignment without clearance in the spline? If he had a tight spline with more radial misalignment than tooth-to-tooth radial clearance (probably our failure cases), the only accommodation is by bending some very stiff shaft and housing systems. Eventually the rear engine bearing wears well beyond its .002" service limit.

I'm not a fan of Cele001's hub spacer as I see it as a 20% solution to a much more serious problem. If anything, a spacer should be created that moves the entire flywheel and clutch pack 6 mm closer to the transmission so that any interfacing radial loads applied by the clutch web are closer to the transmission's spline axial center.

Another revelation is that the alignment pins are very short (.78 inches) X .533 inches OD. Is it possible that if the clutch pack has been initially poorly aligned, that the pins are cocking and coining the aluminum housings at the time the engine transmission bolts are tightened dragging the clutch disk across the flywheel?

Confusing all this is we have many bikes that present no spline service difficulties.

What happens to the rear main bearing radial load if you move the hub closer to the trans?

Your last line I think is likely the reason BMW hasn't done anything about it. The failure rate at whatever mileage bogie they think appropriate is low enough that they don't feel the need to improve. To you point about the alignment pins, it appears there are lots of things that will contribute to these failures. Some bikes stack up too far in one direction and fail early. Comparing new and old friction disks, if the splines weren't gone in my old disk I could put it back in and probably get another 75K. New disk measures 6.50mm. The old is worn to 6.10 on the OD.

nrpetersen · Nov 3, 2015

Tight spline and more engagement should make for lower contact stress and less relative sliding motion/wear between male/female splines?

What happens to the rear main bearing radial load if you move the hub closer to the trans?

The relative ID to OD sliding motion of the spline teeth is determined by the radial misalignment minus the tiny bit of shaft and housing deformation, minus the radial clutch disk slippage on the flywheel face. The number of teeth doesn't make any significant difference. Few big teeth vs many small teeth - all the same unit loading. After a while the main bearings wear until the crank can establish a new operating centerline.

The rear main bearing loading will be limited by the clutch disk-to-flywheel friction. I don't think moving the spline hub will affect it much.

I suspect the reason BMW has not done anything callback-wise is that there is no way they can easily check alignment without a horrendously costly disassembly. And even if 10 percent of the bikes eventually will fail (my WAG), most will be out of warranty such that they can just tough it out.

Just how bad is your old input shaft spline? It does not have to be perfect to get a lot of miles out of it - especially if there is no relative motion/radial misalignment. Have you got a clear photo of it?

roger 04 rt · Nov 4, 2015

2dflier said:
Tight spline and more engagement should make for lower contact stress and less relative sliding motion/wear between male/female splines? My head is starting to hurt. Too many moving parts.

...

Couple that with the angular geometry introduced by the hypothesized straight radial offset. In other words if you hypothesize the the transmission is shifted down, the the clutch disk has to either: slide around during rotation; or the clutch web has to flex at an angle. The later seems more likely and more consistent with the wear pattern on the input shaft--more wear on the inboard portion. In that model a greater insertion and tighter connection matter, meaning that more insertion helps.

Your point about a tighter connection meaning less sliding and wear is a key idea. After all it takes "work" to wear the surfaces, and "work" is "force" times "distance". So less sliding "distance" has to mean less wear.

2dflier · Nov 4, 2015

nrpetersen said:
Tight spline and more engagement should make for lower contact stress and less relative sliding motion/wear between male/female splines?

What happens to the rear main bearing radial load if you move the hub closer to the trans?

The relative ID to OD sliding motion of the spline teeth is determined by the radial misalignment minus the tiny bit of shaft and housing deformation, minus the radial clutch disk slippage on the flywheel face. The number of teeth doesn't make any significant difference. Few big teeth vs many small teeth - all the same unit loading. After a while the main bearings wear until the crank can establish a new operating centerline.

The rear main bearing loading will be limited by the clutch disk-to-flywheel friction. I don't think moving the spline hub will affect it much.

I suspect the reason BMW has not done anything callback-wise is that there is no way they can easily check alignment without a horrendously costly disassembly. And even if 10 percent of the bikes eventually will fail (my WAG), most will be out of warranty such that they can just tough it out.

Just how bad is your old input shaft spline? It does not have to be perfect to get a lot of miles out of it - especially if there is no relative motion/radial misalignment. Have you got a clear photo of it?

I didn't take any pictures of the input shaft splines. There was definitely wear - maybe more towards the middle - but there looked to be plenty of meat left. The trans had been rattling in neutral for 20K miles and started making something of a grinding noise going down the road the last couple of hundred miles, which is why I pulled the trans. It's currently at the local shop waiting to be looked at - for over a week. So I didn't really bother too much with the spline thinking that the case would have to opened up and bearings replaced. The shaft I figured would just get replaced. The clutch splines were much more concerning. I figured it was just a matter of time before I was sitting on the side of the road wondering why I didn't pop for towing...

nrpetersen · Nov 4, 2015

I think you take the record for getting home while being closest to a total spline strip out. Your luck has been pushed. Don't expect any more! :beer

Try to recover the shaft. If nothing else, I'd like to check its hardness profile. (I have local friends that can get us Rc measurements)

This is a pretty clear case of the wear profile including the effects of the disk spider being flexed. A greater engagement would have postponed failure some, but the real problem remains the radial alignment error. The new pin offsets (if you want to go that route) should take the rear main bearing wear into account because the clearance makes the crank run on an average new centerline.

You have a choice - find another transmission on ebay, or fix this one and I'll make up offset pins. Do you want the alignment check fixture (the blue thing with a dial indicator on it per SpaffyPD's postings)? I'll need a shipping address.

2dflier · Nov 5, 2015

nrpetersen said:
I think you take the record for getting home while being closest to a total spline strip out. Your luck has been pushed. Don't expect any more!

Try to recover the shaft. If nothing else, I'd like to check its hardness profile. (I have local friends that can get us Rc measurements)

This is a pretty clear case of the wear profile including the effects of the disk spider being flexed. A greater engagement would have postponed failure some, but the real problem remains the radial alignment error. The new pin offsets (if you want to go that route) should take the rear main bearing wear into account because the clearance makes the crank run on an average new centerline.

You have a choice - find another transmission on ebay, or fix this one and I'll make up offset pins. Do you want the alignment check fixture (the blue thing with a dial indicator on it per SpaffyPD's postings)? I'll need a shipping address.

My luck usually doesn't run that way so maybe I should start playing the lottery again.

Many thanks for the offer to make a set of offset pins. Given more time to play around, less need to get the bike back on the road, and a desire to extend the service life, I'd investigate this much deeper. It's interesting. But 90K+ miles without intermediate spline maintenance has to be good enough for now. I really have no expectation of keeping the bike for that long. The trans is out for repair but I will be sure to retrieve all replaced parts and would be happy to ship you whatever you'd like to see - including clutch parts. Speaking of time... Late for work.

froggy · Nov 7, 2015

This past fall my splines shredded at 32000. Pulled trans and had my mech. install new shaft and seals (did not replace bearings due to mileage), the friction plate was like New except the hub. Bought the hub extender, bought oil soaked friction plate off of inmate on this site and switched out his good hub with my threaded hub. So I was able to 're-use my friction plate with adapter installed and it only cost me shipping of the oil soaked plate and cost of adapter. Told mechanic to give me old shaft and I used that as my alignment tool. Have ridden it hard for the last 1500 miles and only problem is a whining in trans in all gears and idle. Is it the front bearing on trans- I don't know... asked my mech and he said that "gear teeth are not in same spot and will need to brake in". True, not true, not sure but fact is I'm NOT pulling that trans back out. What a pain in the $&#@&$ that is.

2dflier · Nov 9, 2015

froggy said:
This past fall my splines shredded at 32000. Pulled trans and had my mech. install new shaft and seals (did not replace bearings due to mileage), the friction plate was like New except the hub. Bought the hub extender, bought oil soaked friction plate off of inmate on this site and switched out his good hub with my threaded hub. So I was able to 're-use my friction plate with adapter installed and it only cost me shipping of the oil soaked plate and cost of adapter. Told mechanic to give me old shaft and I used that as my alignment tool. Have ridden it hard for the last 1500 miles and only problem is a whining in trans in all gears and idle. Is it the front bearing on trans- I don't know... asked my mech and he said that "gear teeth are not in same spot and will need to brake in". True, not true, not sure but fact is I'm NOT pulling that trans back out. What a pain in the $&#@&$ that is.

I guess gear whine makes sense. The front input bearing finally going out save me from totally stripped splines. They were close but after 95K miles the friction disk was hardly worn. But the clutch housing and pressure plate were worn so the whole thing had to be replaced. I'm just waiting on the new clutch servo to finish up the install but when it comes time for a spline lube I'm thinking a day trip to a professional. It's more than a day job for me and removing the trans is not something I want to get good at.

nrpetersen · Nov 9, 2015

froggy said:
Have ridden it hard for the last 1500 miles and only problem is a whining in trans in all gears and idle. Is it the front bearing on trans- I don't know... asked my mech and he said that "gear teeth are not in same spot and will need to brake in". True, not true, not sure but fact is I'm NOT pulling that trans back out. What a pain in the $&#@&$ that is.

Gear teeth only wear to a more noisy condition. You must have a worn/loose input bearing.

And gear teeth should not have to "break in". I once had a 1:1 set of noisy high speed gears on an industrial application that I tried to wear in with lapping compound. That didn't work at all & a gear guru explained why. :banghead

froggy · Nov 12, 2015

Did check for looseness in front end of trans before handing it to my mech. DoddDmmDoddD not check too closely due to mileage and trans was quiet prior to input shread, only told him to replace all seals.

Clutch and input shaft spline - need advice please

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