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Transmission input shaft spline lubrication


kalali

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Hi nrp, Thanks for that info, very informative. I guess I've just been lucky after 40 years on BMW bikes and never had spline problems. (My replies are in italics)

 

On your R90/6 did you ride a lot on wet roads that had been heavily salted previously? It has exactly never seen Minnesota salt. Very glad Oregon does not use sodium chloride just sand. You are lucky!

 

I think there are several problems that can cause spline issues and mis-alignmenet may be one of them for sure. I also think that rider riding technique is also an issue (I don't really think it is a major factor) and might even cause a rear main bearing issue. I'm referring to the effects of flat twin rocking couple (this is a force that only rises with the square of the rpm)and how it might effect the rear main especially if the bike is ridden at low RPM in the higher gears. (that's probably me though compared to most performance riders. Journal bearings though can take tremendous shock loads like from an imbalance etc, but they are not good for a sustained load operation with sustained unidirectional loads when running at low speeds - especially if the oil is hot.) lack of full spline clutch hub mating in the 1150 may also be a contributing factor. Then we have BMW itself and their business philosophy and on and on....

 

I'm hardly a mechanical engineer just a long time rider with what I hope is a bit of common sense. You guys are the ones that give engineers "realism therapy!" I do all of my own maintenance and in the case of my 1150RT it has never been in any shop other than my own since day one and that includes the first service at 600 miles. Now the bike has just over 50K miles and has perfect splines. In that 50K miles it has not spent even 100 miles in 6th gear. The '93 R1100RSL I bought 3 years ago with only 1 mile on the odometer and I did the first service. I also, before ever starting it for the first time, separated the trans from the engine and lubricated the splines with Honda moly and Sig 3000 50/50. What did you find from the factory grease job? (My R1100RT at 20K had only the slightest coating of something that really looked like a varnish. I was very surprised how thin it was.) Bike has also never been in a shop (mine either). Some folks argue that spline lub is un-necessary others think differently. (That depends on how well their centering happened to be - especially if they don't regularly lube them.) Maybe I've just been lucky, point is who knows??

 

Oh, have I ever mentioned that I just love the performance I get from my 1150 with LC-1? (My R1100RT is still the stock control processor control etc system. I fought surging until I started fiddling with the "do not touch" throttle stop screws.) Hi Craig :rofl:

 

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Hi nrp, To answer your question about what i observed on my new 3 years ago R1100RSL splines. I found a very small dab in one spot of something that looked like very light grease. I do tend to think that a severely mis-aligned engine/trans machine will not benefit much from spline lube.

 

I think we are pretty much on the same page where this issue is concerned.

 

I attempted to cure the slight surge on my 1150 by adjusting the throttle stop screws but that really didn't seem to make much difference.

 

I am most interested to see how Craig makes out after he has his injectors cleaned and balance tested. I guess this really belongs on another thread, sorry.

 

Happy holidays to you. :wave:

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  • 3 months later...

Used "search" to find what I wanted so I'm resurrecting an old thread here just to say thanks to all for the insight gleaned on the splines topic.

 

2000 R1100RT, and I feel much better about just riding and not worrying with the splines.

 

 

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  • 2 weeks later...

Chris Harris from your side of the pond says that spline problems are caused by riding in 6th Gear before you hit 70- 80mph !!

 

Not good as it causes too much friction and then vibration as the revs are too low for 6th gear Makes sense for me like not sure about you Any comments guys?

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Chris Harris from your side of the pond says that spline problems are caused by riding in 6th Gear before you hit 70- 80mph !!

 

Not good as it causes too much friction and then vibration as the revs are too low for 6th gear Makes sense for me like not sure about you Any comments guys?

That's his opinion. Not mine whatsoever. See above.
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Chris Harris from your side of the pond says that spline problems are caused by riding in 6th Gear before you hit 70- 80mph !!

 

Not good as it causes too much friction and then vibration as the revs are too low for 6th gear Makes sense for me like not sure about you Any comments guys?

 

Afternoon dougied

 

 

Lugging the 1150 BMW might add a little to the overall problem but I (personally) know of 2 early 1150RT spline failures that happened on bikes that were never lugged or chugged around in too high of a gear.

 

One the other hand I know a rider with a 2003 1150RT that rides his bike like it's a tractor & is almost always a gear or two too high. He has a bit or 85,000 miles on the original trans input shaft & clutch.

 

My personal opinion is the spline failure is due almost exclusively to trans/to/engine mis-alignment issues.

 

If you look at the severe wear pattern on the splines they are very angular. You would think that IF the spline failure was due to engine lugging then the spline wear would be even front to rear (not angular) & show a LOT more fretting.

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Stan Walker

I tend to use lower rpm ranges all the time, often cruising at 3000-3400 in 6th gear. My 02 RT is at 134,000 miles on the original clutch and input shaft splines. As of a recent check through the starter hole it is still good to go!

 

Stan

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One argument supporting the "lugging" scenario was the spline failures are a lot less common on the GSs of the same era since they are ridden harder (or higher engine speeds). True or false, you be the judge.

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One argument supporting the "lugging" scenario was the spline failures are a lot less common on the GSs of the same era since they are ridden harder (or higher engine speeds). True or false, you be the judge.

 

Evening kalali

 

A lot less common yet in 1150RT's with whitewall tires. Way more 1150RT's than 1150GS's in that time frame.

 

I do know of a couple of 1150GS with trashed input shafts though.

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roger 04 rt

The idea that running higher gears at lower RPMs is wearing the shaft/hub doesn't stand any reasonable test of science or physics. The only time the input shaft to the transmission is highly loaded is when the throttle is widely opened.

 

They guys who ride in low gears, with the throttle wide open to redline put the highest torque load AND the highest power transmission load on the clutch hub and input shaft.

 

In 6th gear at 50 mph, the torque on the input shaft is about 13 lb-ft. Even if you yank it to WOT the HP is only 28 HP. By contrast if you're in 3rd gear at 7000 Rpm at WOT you're at 70 lb-ft torque and 80-90 HP. It's clear which is the greater load.

 

These bikes wear the input shaft and clutch hub due to alignment issues but I don't think the interplay of alignment issues is fully understood.

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Actually the low rev high gear scenario supports the misalignment argument. The spline wears are not because of excessive load. In fact, the higher the load the lesser the wear. If you compare the length of the shaft with the depth of the hub, the less load contributes to the effects of the misalignment. None of these would be an issue is the shaft was long enough to seat fully inside the hub. Just like how it should have designed in the first place.

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The idea that running higher gears at lower RPMs is wearing the shaft/hub doesn't stand any reasonable test of science or physics. The only time the input shaft to the transmission is highly loaded is when the throttle is widely opened.

 

They guys who ride in low gears, with the throttle wide open to redline put the highest torque load AND the highest power transmission load on the clutch hub and input shaft.

 

In 6th gear at 50 mph, the torque on the input shaft is about 13 lb-ft. Even if you yank it to WOT the HP is only 28 HP. By contrast if you're in 3rd gear at 7000 Rpm at WOT you're at 70 lb-ft torque and 80-90 HP. It's clear which is the greater load.

 

These bikes wear the input shaft and clutch hub due to alignment issues but I don't think the interplay of alignment issues is fully understood.

 

Morning Roger

 

I think the few that think the spline wear is based on engine lugging are basing that assumption on the low RPM 2 cyl boxer's very harsh (low RPM) firing pulses (basically hammering), not the max torque being carried through the spline joint.

 

There is some validity in that assumption based on single cylinder & 2 cylinder agricultural equipment (like old John Deere tractors) that did have excessive spline coupling, splined flywheel, & splined clutch driver wear from (lugging) from the 2 cylinder very harsh low RPM hammering-like firing pulses.

 

I have seen a number of old 2 cylinder tractors hammer the splines from anywhere to completely stripped out to re-contoured spline shape with thin peaked spline teeth.

 

The BIG difference I see in the spline wear on the old 2 cylinder tractors & the 1150 BMW 2 cylinder boxer is the 2 cylinder tractor spline wear is symmetrical & even across the entire spline engagement with very heavy fretting & the BMW boxer wear is very angular & smooth (more of a wiping action)

 

One of the things that really supports the mis-alignment theory as the root cause (in my mind anyhow) is the very similar (almost identical) angular spline wear & spline failure on high powered jet boats. The jet boat spline wear is almost always traced to engine to pump misalignment (both angular & straight offset).

 

 

 

 

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Hi Roger, As you know I'm one of those that thinks lugging around in 6th at 50 mph is not good for survival of input shaft splines. I realize that if one rides in 5th at higher speeds and thus high engine RPM more torque is delivered from the boxer motor. Thing is this high torque has MUCH LESS LOAD RESISTANCE when the trans is in fifth rather than 6th gear. The end result is less pressure on the input shaft splines. I also think that the power pulses from the two cylinder opposed twin together with the inherent rocking couple effect add to spline wear. Then there is the issue of only partial spline engagement with the clutch disc splines on the 1150 with the 6 speed trans. The engine trans misalignment theory, if true, doesn't say much for BMW quality control and it's hard for me to believe that BMW would choose to overlook such an important issue. Maybe I'm too trusting?

 

On a side note I swapped out the LC-1 for an LC-2 on my '04RT so I have a perfectly good LC-1 for anyone that wants it with O2 sensor, FREE! You pay postage. :)

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roger 04 rt
Morning Roger

 

I think the few that think the spline wear is based on engine lugging are basing that assumption on the low RPM 2 cyl boxer's very harsh (low RPM) firing pulses (basically hammering), not the max torque being carried through the spline joint.

 

There is some validity in that assumption based on single cylinder & 2 cylinder agricultural equipment (like old John Deere tractors) that did have excessive spline coupling, splined flywheel, & splined clutch driver wear from (lugging) from the 2 cylinder very harsh low RPM hammering-like firing pulses.

 

...

 

Afternoon DR,

 

Understand that the "lugging theory" might also include the view that hammering is a part of the problem, but as you point out the shape of the wear is more consistent with misalignment of various elements in the clutch and transmission.

 

My counter to the lugging theory is that whatever gear the bike is in--4th vs 3rd, 5th vs 4th, etc.--the proportional increase in the force on the shaft is small, a 15-25% variation in most cases. My point is that engine load (throttle angle) accounts for a 10 times increase in force at the coupling under WOT acceleration. So by driving in 5th rather than 4th I add a 15% load on the coupling. Even if you say that all the engine torque is created in 1/10th of the engine rotation (the hammering), which makes sense, the hammering force is still only proportionally higher.

 

A point on the hammering theory is that there is a spring coupling on the input shaft that should be absorbing the peak torque forces and spreading them over time as the spring is loaded and then unloaded.

 

Although I can't see gearing or gear selection as anything but a minor factor ... misalignment, clutch pack deformation, coupling tightness (insertion depth) and even hammering (high peak torque forces) all have a true ring for me.

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