Final Drive Update/Question

[parkec]

I searched the R1200R posts prior to this post.

A buddy of mine just lost his second R1150R final Drive on the way back fotr MOAfirst one 50,000+, second one was usted with atotal of 35,000 miles. My buddy beileves its engineering vs materials or lubes...hes once again talking Moto Guzzi...we'll see.


Now my question.......Most of the failures I'm familiar with are on the 1150...true or coincidence/my cofcle fo bmw owners?

[deilenberger]

I searched the R1200R posts prior to this post.

A buddy of mine just lost his second R1150R final Drive on the way back fotr MOAfirst one 50,000+, second one was usted with atotal of 35,000 miles. My buddy beileves its engineering vs materials or lubes...hes once again talking Moto Guzzi...we'll see.

Now my question.......Most of the failures I'm familiar with are on the 1150...true or coincidence/my cofcle fo bmw owners?

The design of the hexhead (1200) rear drives is completely different from the R11xx series. While some failures have been seen, it hasn't been as evident as the R11 failures. BMW made some changes to the hexhead drive and to the service schedule for them, and it's rather rare now to hear of a failure. MotoGuzzi recently changed their rear-drive design, I have no idea why since I don't follow MG.. nor do I know how reliable it is.

[psycle.vt]

On the 1150GSs and presumably on the 1150R, 50k was about normal for the first failure (mine happened at 57k I think). The common wisdom is that the failures are due to inaccurate shimming and that quite often the replacements are not checked for this and so can fail again. Tom Cutter in Yardley, PA is one of the gurus of these.

[moto-m]

The FD on my 1100 went down around 52,000 miles. The BMW dealer's head technician who changed the bearings did re-shim saying effectively, that he considered that it had not been done properly during manufacture. He didn't put it across to me like that at the time, of cause. I think that it was along the lines of him having a different idea of how it should be. I hope that he's right.

Mike
Cheshire uk

[parkec]

My buddy installed his back up FD last Friday.. Say 5 days ago.

Shaft drive seal failure.

I won't say he is despondent, but he was out looking at a Honda cbr1000r.

[garr2]

The design of the hexhead (1200) rear drives is completely different from the R11xx series. While some failures have been seen, it hasn't been as evident as the R11 failures. BMW made some changes to the hexhead drive and to the service schedule for them, and it's rather rare now to hear of a failure.

I hope your right because I'll soon be moving from an 1150 to a 1200.
I've just got through dealing with the second FD failure on my 1150 - the first at 112000 km, the second at 119000. Mmmm...
Thankfully the second was fixed free of charge by the dealership.

Ian

[def]

FD failures occur almost randomly. Some Paralever owners who perform their own FD oil changes have been able to predict an impending FD failure. Inspection of the smut on the magnetic drain plug often provides a good assessment of the condition of the FD internals.

A failure usually comes as a result of the crown wheel bearing cage rivets loosening and eventually breaking. This allows the cage to come free. The steel cage is then “run over” by the balls in the bearing assembly. This results in catastrophic failure, possible damage to other FD components, damage to the oil seal and loss of the lubricating oil in the FD. If the oil leaks while riding at speed, a crash can result due to the rear tire being oiled by the FD oil leaking onto the tire. BMW changed the crown wheel bearing design (number of balls in the bearing assembly) at one point in an apparent attempt to reduce failures.

Many who have observed this failure first-hand believe assembly was carried out with improper preload setting. BMW shops often do not rebuild or repair FDs but only install a new complete FD assembly. This is costly and unnecessary.

While I am not familiar enough with the newer “hole in the middle” style FD, the older style FD can be rebuilt successfully. Complete FD repair is covered in detail in the factory REProm.

A successful FD rebuild often requires a new crown wheel bearing, a new oil seal, o-ring and the appropriate shims for establishing recommended preload. These parts usually total less than $120.00. Medium level skills are required to perform the work correctly and successfully. A torque wrench is recommended for proper assembly. A measuring device such as a dial indicator or vernier caliper is used to determine the appropriate shims for correct preload. A FD rebuild can be carried out in a few hours. Some heating and chilling of various components facilitates assembly.

Currently, FD failures seem to be less frequent inasmuch as most failures have already been addressed.

Unless there is irreparable damage to your FD, don’t overlook rebuilding the unit. Most who have done so, never experience another FD failure.

[deilenberger]

def,

It doesn't sound as if you're describing the current rear drive from BMW. The large bearing is external to the drive. No seal needs replacing if that bearing starts going bad (and they seem to fail due to excess play, but I haven't seen one torn apart to see what happened..) AFAIK, there is no re-shimming required since the crown wheel is located with that bearing and the other end floats free horizontally in a needle bearing assembly.

What you describe does sound right (including the changed "big" bearing) for the earlier R11xx and K12-brick series of bike drives.

Just a FWIW..