Loose final drive pivot

[Bart Anderson]

I need opinions. Bike is a 2000 RT with 41k. Did an 860 mile run to Milwaukee and back on Friday and Saturday, and during pre-flight for a Sunday ride noticed quite a lot of play in the rear wheel.

 

Closer inspection revealed that the right side final drive pivot bolt was loose and backing out! I was able to tighten it up about 3/4 turn by hand (while wiggling the rear wheel), then cranked on it with a 10" breaker bar, since I don't have a torque wrench that goes up to the called-for 150 Nm. There is now just a barely-there amount of play in the wheel...about the same as my buddy's R1100S. I rode another 300 miles on Sunday, and all seems well.

 

So, dear friends, am I ok to run these pivot bearings throught the rest of the season, or should I get on it now? I assume they took quite a beating while that bolt was loose, but it feels ok now and I'd really prefer to do the replacement over the winter.

 

I'll appreciate your input!

[impilot]

Well, at a minimum I would get some lock tight and torque as specified. You can also pretty easily remove the rear end and actually rotate the bearings and see if they feel smooth. FWIW, they are $23 dollar bearings (check the classifieds...Bargalowski has some for sale) and pretty easy to replace. If it were me, I would put some new bearings in, re-torque and lock tight the rear end. It's really not that big of a job. And it is for sure a much easier job to deal with at home, on your schedule, than out on the road while on a trip.

 

John

[Stan Walker]

am I ok to run these pivot bearings throught the rest of the season

 

Ride it, check play every week.

 

Stan

[USAF1]

I'd have to say NOT.....only because you might have already "Flattened" the surfaces of the needle bearings in there. And it's probably full of crud and dried grease anyway. I vote for replacement.

 

Pat

[smiller]

I would adjust them properly (7 nm torque on the left side adjuster) and then just check things out for a while, weekly at first. If the play doesn't increase over time I would say that you are safe for the rest of the season at least.

[Bill Dennes]

Sounds like somebody removed the pivot at some point and did not clean and Loctite it when reinstalling.

 

Use Red Loctite, torque to spec and ride. When you get a chance, make sure the swingarm pivots are tight.

 

If the pivot bolt was backed out of the bearing, it sure wasn't hurting the bearing.

[Clive Liddell]

Bart,

I agree with the "ride it and check bearings when convenient" suggestion.

 

The regular quick and dirty checking of "play" is easy and should be done by all of us - bike on centre stand, push down on rear rack/seat till tire is firmly on solid surface and smartly rock rear of bike from side to side...

[Barglowski]

Considering that to normally remove that bolt, you have to spend 5 min with a heat gun on the bolt, then overcome 105Nm torque! Since John (impilot) and I have done this 10 times in the last 3 weeks (2 spline lubes (with swingarm bearing), 1 final drive replacement) I hope there's a reason for that insane torque value!

 

My bearings at 72k had an impression in them. I've heard of some people rotating them and reusing them, since the travel in only a few degrees of rotation.

 

Tricks to remove those bearing for replacement:

- Remove final drive

- Pop off FD shaft with large screwdriver thru the U-joint. Protect casing with cardboard/plastic

- Using punch or large screwdriver, tap the *opposite* side outer ring of bearing thru the casing. Tap a bit, then move to another section and gradually tap out the bearing. Go like 12, 3, 6, 9 o'clock...

- Put the new bearings in the freezer

- Heat the casing with a heat gun for 5 min or so.

- Tape (duct, electrical) the old outer ring to the new bearing, taking care to match the *thin* sides together.

- Secure the casing so that you don't hit the rotor, or mar the casing on the garage floor, etc.

- Using a large striking surface (I used the top of a 5 lb sledge), gently tap the bearing into the casing by hitting only the old bearing ring. Make sure you take your time, setting the new bearing into the case uniformly. The tape should shear off the bearing as it progresses into the casing. Take care for the last few hits, as there won't be much tape aligning the ring to the bearing!

- Or, use an arbor press

- Do the other side

- Pop the FD shaft back on with a rubber mallet.

- Install the FD with loctite and torque.

 

What was your original question, now? I just had to write all that down since it's still fairly fresh in my mind...

 

Later,

jan

[GordonB]

If you've got a LD close by try dropping by (w/appt); I had mine readjusted, re torqued, reloctited, all for about $30 Bucks, and piece of mind. No worries, lots a riding thereafter.

[Bart Anderson]

Thanks everyone. I'm going to just check it often and ride, then replace the bearings when the snow flies.

 

FWIW, I'm not aware of that bolt ever having been touched, and I've owned the bike since new. Maybe Hans at the factory was hungover that day.

 

Thanks again...

[Sean]

I'd recommend replacement of those bearings as soon as possible. Those needle bearings don't take well to thrust loads like what they were subjected to when they were loose. They're pretty easy to replace, even with the swingarm still mounted to the bike. If those were the original bearings and have 41K on them, they should be replaced anyway. They generally go kaput in the 25K-35K mile neighborhood. Take the time to get the preload properly adjusted before tightening down that locknut. I've found that the spec in the BMW service manual (something like ~10Nm) is usually a bit too low and still results in a bit of swinarm play, so you might try something in the ~12-15Nm range (basically gradually tighten until all slack/play is taken out) before tightening the locknut, be sure to use locktite.

 

BTW, the application of heat is not required due to the high torque value, rather it's to loosen the locktite on the nut.

[Bart Anderson]

Well, in preparation for a 4-5k trip next week I went ahead and replaced the bearings last night. It was a relatively painless procedure thanks to all the advice here on the board.

 

The right bearing was in very good shape, the left one was only slightly notchy. They probably would have been fine for a while longer, but I'm glad I did it for the peace of mind factor.

 

One note on the "play"...previously when people would say there should be NO play at all, I would think to myself "oh, bullpuckies--this little bit of play should be fine..." Well, with the new bearings installed and properly torqued, there is absolutely NO PLAY at the pivots. I'm a believer now.

 

One other question: the U-joint appears to be in great shape, but the Haynes manual says there should be no notchiness. There is a very pronounced notch in my U-joint in the center of both planes of movement...it's a single, somewhat soft notch in both directions...very consistent and in what seems to be the exact center of each plane...like it's supposed to be there. I put it back together and intend to ride it, but wonder what others think about this--is this U-joint bad?

 

Thanks again for the advice...