tranny input shaft

Blacque Jacque Shellacque said:

Paul, your bike has considerable mileage. Quite likely more then most of us will ever obtain. I am very curious if your seeing even wear along the length of the spline? Or like many of us, more wear at the transmission end of the spline.

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Like all 1150s, mine shows the short non-contact area nearest the transmission. But the contact area appears to have worn in a linear faqshion, aligned with the axis of the shaft. I don't have the barrel shape which we saw with the K75s with faulty auxiliary cases.

spline update

I thought I might get flamed with my rant that started this whole thing... thanks for sparing me.

I wound up taking my gearbox to Perry in Ft. Worth about 10 days ago, still no word on where he is in the rebuild. In the meantime I did come across an 02 RTP that the PO had just put a new clutch in, but wound up with some kind of wiring problem exacerbated by some serious health issues that prevented him from returning it to service. I pulled the gearbox and found the splines to have considerably less wear (RTP had 47K on it) than mine did at 57K, and had Perry not already been into mine I might have used it. So for now I have a parts bike that the PO said ran great for the 40 miles or so he rode it before starting the clutch replacement. So this may need to be another thread, but given that there are many parts that will interchange I was wondering what would be on the top of the list to scavenge and keep?

The alternator is a 60 amp unit and appears that it is candidate to use (at an alternator shop making sure the wiring harness issue didn't toast it), and I like the idea of having a fan on the oil cooler- so I'll probably retrofit that with a toggle switch. I'd almost rather have the unlinked ABS from the RTP - but can only imagine it would be next to impossible to make that work right, so unless somebody tells me its an easy swap I'll probably pass on that one.

Brake calipers, rotors, final drive and shafts.. I'll probably keep for spares. Did I miss anything?

awagnon said:

I'm currently watching the splines on my "04 1150GS. There was significant wear two years ago and I'll be taking another look in a couple of weeks

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Just a short followup on my previous post. I checked the splines on my '04 1150GS exactly two years and 20,000 miles ago when the bike had about 20,000 miles on the odometer. The input shaft showed about 10% wear and the splines inside the clutch disk were 20-25% gone. I didn't have the tools or skill to check for a misalignment, so I just replaced all clutch parts south of the crank shaft in case there was a run-out issue and re-lubed with moly grease from Guard Dog as recommended by Paul Glaves. I took the bike apart today and the splines in the clutch disk look brand new and the wear on the input shaft has not gotten any worse in the last 2 years and 20,000 miles. So, either replacing all of the clutch or using the Guard Dog grease prevented what should have been significant wear. I'll look again next winter if I still have the bike, but based on my limited experience, I would recommend this if you have sub-critical spline wear.

awagnon said:

......... I didn't have the tools or skill to check for a misalignment, so I just replaced all clutch parts south of the crank shaft in case there was a run-out issue and re-lubed with moly grease from Guard Dog as recommended by Paul Glaves. I took the bike apart today and the splines in the clutch disk look brand new and the wear on the input shaft has not gotten any worse in the last 2 years and 20,000 miles. So, either replacing all of the clutch or using the Guard Dog grease prevented what should have been significant wear. I'll look again next winter if I still have the bike, but based on my limited experience, I would recommend this if you have sub-critical spline wear.

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Has BMW been religious about greasing these on initial assembly? With what, and how much, too! When I looked at my R11000RT at 24K miles, it seemed like only maybe a thin coat of varnish had been put on the splines.

nrpetersen said:

Has BMW been religious about greasing these on initial assembly? With what, and how much, too! When I looked at my R11000RT at 24K miles, it seemed like only maybe a thin coat of varnish had been put on the splines.

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Going as far back as the classic K bikes in 1985 - no, BMW has not been particularly consistent in the application of spline lubricant. On both K bikes and Oilheads I have seen dry splines at as few as 6,000 miles. As for what do they use, again going back a ways they have specified: anti-seize, Stabarugs assembly paste, Otpimoly paste, BMW #10 red grease (like Texaco Starplex), and whatever they are using now. I lost track a few years ago.

I believe that the "varnish" you found was the remains of BMW#10 red grease after all the liquid drained off in the first instance of 100 F plus tempertures. That stuff would drip and drain out of the grease gun on the shelf in the shop at 90 degrees F. If ever in the history of mankind did anybody specify something as unsuitable for splines as #10 red grease a bolt of lightening probably struck him or her immediately. BMW gets a lot of things right but spline lubrication has not proven to be one of those things.

PGlaves said:

I believe that the "varnish" you found was the remains of BMW#10 red grease after all the liquid drained off in the first instance of 100 F plus temperature. That stuff would drip and drain out of the grease gun on the shelf in the shop at 90 degrees F.

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Must be a common characteristic of red grease!

PGlaves said:

Like all 1150s, mine shows the short non-contact area nearest the transmission. But the contact area appears to have worn in a linear faqshion, aligned with the axis of the shaft. I don't have the barrel shape which we saw with the K75s with faulty auxiliary cases.

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Paul, thanks for the update.

Very interesting. Linear wear along the shaft. Perhaps it has been mentioned before, but this seems to be solid evidence that the Non fully engaged clutch hub of the 1150's is not responsible for the odd barrel wear seen on a lot of bikes.

Blacque Jacque Shellacque said:

Paul, thanks for the update.

Very interesting. Linear wear along the shaft. Perhaps it has been mentioned before, but this seems to be solid evidence that the Non fully engaged clutch hub of the 1150's is not responsible for the odd barrel wear seen on a lot of bikes.

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Barrel wear could happen when the clutch hub spline is near or after complete failure. That would jibe if the end of the shaft is slightly harder than the rest of the shaft, assuming the clutch hub is about equal hardness over its length.

Barrel Shaped Spline Wear

If the shaft is not a perfect 90 degrees to the plane of the disk hub (or put another way - exactly parallel and coincident with that hub) then the angular alignment can/will cause barrel shaped wear.

I know of two causes:

1. Bolting the transmission and engine case together in a manner that has the transmission shaft and crankshaft not in perfect alignment.

2. A bent/deformed clutch housing which holds the disk in a position which "wobbles" on its axis.

I have replaced a couple of clutch housings (flywheels with the starter ring gear) because by eye they were noticably bent. These pieces on Oilhead bikes are flat steel and are easily bent during either assembly or disassembly.

When you take pone of these apart and find barrel shaped wear on the shaft, I would recommend that the first thing you do is check the axial runout (front-to-back) on the flywheel (clutch housing).

PGlaves said:

When you take pone of these apart and find barrel shaped wear on the shaft, I would recommend that the first thing you do is check the axial runout (front-to-back) on the flywheel (clutch housing).

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Have you ever measured axial run out (i. e. an angle between the two axes)? That would seem to be very easy to minimize from a manufacturing methods standpoint. Radial run out on the other hand, isn't. Of course an accident could bend the clutch housing etc.....

nrpetersen said:

Have you ever measured axial run out (i. e. an angle between the two axes)? That would seem to be very easy to minimize from a manufacturing methods standpoint. Radial run out on the other hand, isn't. Of course an accident could bend the clutch housing etc.....

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The big issue I have seen with these clutch assemblies is that the pins on the clutch cover go through the tangs on the pressure plate and into holes in the clutch housing (flywheel). The pins can stick in the holes, and, unlike the classic K series with a fairly thick cast aluminum housing, the thin stamped steel housings on the R11xx bikes can bend easily if there is the slightest bit of ham handedness in either disassembly or reassembly. That is where I think most of the cases of wobble are coming from. And yes - I have used a dial indicator to measure axial runout.

bsample said:

I thought I might get flamed with my rant that started this whole thing... thanks for sparing me.

I wound up taking my gearbox to Perry in Ft. Worth about 10 days ago, still no word on where he is in the rebuild. In the meantime I did come across an 02 RTP that the PO had just put a new clutch in, but wound up with some kind of wiring problem exacerbated by some serious health issues that prevented him from returning it to service. I pulled the gearbox and found the splines to have considerably less wear (RTP had 47K on it) than mine did at 57K, and had Perry not already been into mine I might have used it. So for now I have a parts bike that the PO said ran great for the 40 miles or so he rode it before starting the clutch replacement. So this may need to be another thread, but given that there are many parts that will interchange I was wondering what would be on the top of the list to scavenge and keep?

The alternator is a 60 amp unit and appears that it is candidate to use (at an alternator shop making sure the wiring harness issue didn't toast it), and I like the idea of having a fan on the oil cooler- so I'll probably retrofit that with a toggle switch. I'd almost rather have the unlinked ABS from the RTP - but can only imagine it would be next to impossible to make that work right, so unless somebody tells me its an easy swap I'll probably pass on that one.

Brake calipers, rotors, final drive and shafts.. I'll probably keep for spares. Did I miss anything?

Click to expand...

Keep the wheels, you never know when you might bend a rim. Glad you did work out a deal with the guy, when I saw that bike in his garage I knew he would never get back together. Keep us posted on a Perry.

I was set to have a clutch/spline lube service done early this year. Then the top end had to be rebuilt. That put it off a bit. Approaching 60K, I think it's only a matter of time.

misalignment?

Based on the photo attached, can anyone tell me if this appears to be a classic case of misalignment?

mhuf said:

Based on the photo attached, can anyone tell me if this appears to be a classic case of misalignment?

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I think there are two equal possibilities both of which Paul outlined below. For the reasons he gave, I think the out of true clutch housing is the more likely.

PGlaves said:

If the shaft is not a perfect 90 degrees to the plane of the disk hub (or put another way - exactly parallel and coincident with that hub) then the angular alignment can/will cause barrel shaped wear.

I know of two causes:

1. Bolting the transmission and engine case together in a manner that has the transmission shaft and crankshaft not in perfect alignment.

2. A bent/deformed clutch housing which holds the disk in a position which "wobbles" on its axis.

I have replaced a couple of clutch housings (flywheels with the starter ring gear) because by eye they were noticably bent. These pieces on Oilhead bikes are flat steel and are easily bent during either assembly or disassembly.

When you take pone of these apart and find barrel shaped wear on the shaft, I would recommend that the first thing you do is check the axial runout (front-to-back) on the flywheel (clutch housing).

Click to expand...

PGlaves said:

The big issue I have seen with these clutch assemblies is that the pins on the clutch cover go through the tangs on the pressure plate and into holes in the clutch housing (flywheel). The pins can stick in the holes, and, unlike the classic K series with a fairly thick cast aluminum housing, the thin stamped steel housings on the R11xx bikes can bend easily if there is the slightest bit of ham handedness in either disassembly or reassembly. That is where I think most of the cases of wobble are coming from. And yes - I have used a dial indicator to measure axial runout.

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runout

If I understand axle runout correctly, doesn't the photo indicate a significant amount of runout? And if so would this lead me to believe that the flywheel should be noticeably warped upon visual inspection?

mhuf said:

If I understand axle runout correctly, doesn't the photo indicate a significant amount of runout? And if so would this lead me to believe that the flywheel should be noticeably warped upon visual inspection?

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You might notice it looking at it from the side with the flywheel turning. But you need the transmission out to see it from this viewpoint and few folks do a lot of turning of the flywheel when the bike is this far apart. You won't notice it just sitting there. That is where a dial indicator comes in to measure the runout.

mhuf said:

If I understand axle runout correctly, doesn't the photo indicate a significant amount of runout? And if so would this lead me to believe that the flywheel should be noticeably warped upon visual inspection?

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Just to clarify terms for people who may be reading:

Take a pencil and stick it through a paper plate - exactly in the center but through at an angle. Twirl the plate and pencil and see it wobble as you turn it. That is axial runout.

as opposed to

Take a pencil and stick it exactly straight through a paper plate but at a point slightly off center. Twirl the pencil and see the edges of the plate appear to move toward and away from the pencil. That is radial runout.

This is kind of a whacky question, but in addition to ham-handedness, could engaging the starter while the engine is running deform the flywheel?

mhuf said:

Based on the photo attached, can anyone tell me if this appears to be a classic case of misalignment?

Click to expand...

I must assume the hub spline is totally wiped out and that the bike was ridden until the spline system failed.

To my way of thinking, this is caused by radial misalignment between the the axis of the engine and the transmission. This causes fretting of the spline teeth. Think of a spline as a 1:1 internal/external gear set to transmit torque between two elements - but hopefully with no relative motion during operation. But in this case, because of the radial misalignment, there is relative motion and a lot of spline tooth face force and fretting as the transmission shaft drags the clutch disk around the face of the flywheel - once every engine revolution.

Which spline element gets worn, depends on which one is harder. I suspect the transmission shaft is extra-hard at the tip, since it is probably induction hardened. The clutch hub is softer but probably uniformly hard over its length so they can broach this part during manufacture.

Assuming there is a radial misalignment, initially the fretting-induced wear between these two parts will be such that they are conjugal. Conjugal simply means that wherever there is contact, there will be wear from one or the other, but not necessarily distributed equally between the two parts along its length. Why not equal? Because there is varying relative hardness of the two parts along their mutual length.

That all works for a while, but at some point the clutch hub will have little hub tooth material left at the engine end, where the shaft is hardest. The hub teeth begin to strip out, engine end first. Then the wear gets serious as finally only a small portion of the hub nearest the transmission is transmitting the radial loading since the hub teeth are completely worn away at the engine end. At the very end, only a small amount (maybe less than 1/8 inch) of hub teeth are carrying the torque, and the whole thing fails. The greatest shaft wear is at the transmission end, since the shaft teeth outlasted the softer hub teeth.

The result is what people have been diagnosing as angular misalignment, but I'll bet that any apparent barrel shaped shafts only are near or after total failure of the clutch hub.

Does this scenario match up with the everyone's observations?