final drive

[Rich06FJR1300]

Hi All,

 

Had a rear flat about a week ago and had the tire replaced. I was headed out for a ride tonight but felt like checking the free play at the rear wheel...now its ever so slight but I can feel some freeplay. There isn't supposed to be any at all right? Bike has about 27k on it. By freeplay i mean i grab the top of the wheel with one hand and grab the bottom with the other and try to tilt it, back and forth along the Y axis..i feel a slight play, very slight...i noticed this when i rode it home the other day after they replaced the tire..at highway speed thought i felt a shimmy. Am I imagining things or is something going on here? May take it to the dealer to have a closer look. Is it possible to adjust those rear pivot bearings? I know the bolt on the left side of the shaft is adjustable and the right side is fixed. May just loosen the left side up to see if I can tighten it and eliminate that freeplay.

[smiller]

Probably just the pivot bearing. If so you may be able to see the rear drive housing move with respect to the swingarm but then again maybe not if the play is very small. If you see the rear wheel move with respect to the final drive housing then you have a different and considerably more expensive problem.

 

Procedure to adjust the pivot bearing is to loosen the locknut on the left side an tighten the adjuster to 7 nm. It may require heat to break the locking agent so that the locknut and adjuster may be loosened. If so then don't use brute force to loosen them because the heavy-duty OEM locking agent used by BMW is very strong and you can do damage if you try to loosen it without heat. Make certain that the threads are clean and completely free of any residual locking agent to that the torque reading is accurate during reassembly. After you set the preload at 7 nm then mark the adjuster and the swingarm (so you can be sure that the adjuster didn't move when you tighten the locknut) and tighten the locknut to 105 nm. You should use more locking agent (Locktite) when you reassemble. BMW says to use red (the real strong stuff) but I have always found the blue (medium strength) to be quite adequate and much easier to deal with during subsequent adjustments. Someone will be along to disagree in a moment...

[Stan Walker]

set the preload at 7 nm

 

The service manual for the R1150RT says

1. Initial torque 9 Nm

2. Backoff

3. Final torque 7 Nm

 

tighten the locknut to 105 nm

 

Make that 160 Nm (clean thread + locktight) for the 1150

 

------------------------------------

 

I realise that these numbers differ from the 1100 numbers. So which is it, use the 1150 numbers on both bikes? Or just on the 1150 RT's? Or is it a misprint in my 1150 manual?

 

Stan

[smiller]

The service manual for the R1150RT says

1. Initial torque 9 Nm

2. Backoff

3. Final torque 7 Nm

 

Picky, picky... but more correct. Stan you always watch out for me.

[Clive Liddell]

Stan, you ask:

 

"I realise that these numbers differ from the 1100 numbers. So which is it, use the 1150 numbers on both bikes? Or just on the 1150 RT's? Or is it a misprint in my 1150 manual? "

====================

The "hardware" on both models seems to be the same and yet, as you note, the locknut torque is very different. What with the loctite that's called for I should have thought that the original, lower, torque would suffice. What does the 1150 manual say about the other, fixed side wrt torque?

[Stan Walker]

What does the 1150 manual say about the other, fixed side wrt torque?

 

160 Nm (clean thread + locktight)

 

Stan

[Bob Palin]

I too have some play that according to SLC BMW is pivot bearing wear, they were non-committal about whether the bearings had to be replaced though they did suggest it as I have 95K on them and no adjustment made for a long time. Replacement is about a 3 hour job according to them. I was planning on a 2000 mile trip over the next 3 weeks and am wondering if I should

 

a) leave alone and hope

2) try to adjust - could this actually make things worse if they are worn?

iii) try to get the bearings changed, I probably don't have time to do this before I leave though.

 

I'm not absolutely clear what bearing we are talking about here - is it #2 in this diagram?

 

 

If not does somebody have a suitable diagram?

[smiller]

Yes, #2 is the pivot bearings. What do you mean by 'some play'? Barely perceptible or very noticeable?

 

If the former then I wouldn't sweat it. Getting them replaced would be the best for peace of mind but if that isn't possible I wouldn't cancel a trip because of it. An adjustment will probably take care of it (for a while, at 95k they will probably need to be replaced fairly soon in any event) and if done correctly shouldn't make things any worse. If done incorrectly, well...

 

I would adjust them now and see if any play returns over the next few weeks. If you adjust them and then see play come back pretty quickly then you probably need them replaced, but more likely that won't happen and if so I would consider them good to go, or at least for another few k miles to cover your trip.

[Bob Palin]

Thanks Seth, I don't have any experience to know relatively how much play there is, but it is just visible and easily felt.

[smiller]

but it is just visible and easily felt.

 

I would consider that a candidate for 'adjustment and go.' I'm sure the bearings aren't in exactly new condition but I think the odds of your being stranded as a result of this are very small indeed.

[Jim VonBaden]

but it is just visible and easily felt.

 

I would consider that a candidate for 'adjustment and go.' I'm sure the bearings aren't in exactly new condition but I think the odds of your being stranded as a result of this are very small indeed.

 

I agree.Many would be surprised to find that they are running around will loose bearings. A mechanic friend of mine said that 50% of all the bikes he works on have loose bearings, and 10% are actually bad, but the owners never noticed.

 

Jim