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Final Drive Play Again - R1100RT


old_farmer

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1999 R1100RT, 22.4K (not a typo) miles, original owner

 

Play when grabbing the rear wheel and rocking. Most pronounced when holding at 12/6, but I can occasionally get it at 9/3. I can feel and hear movement. I can't see it. I can't detect by feel movement of any parts of the final drive relative to the swingarm, so whatever movement there is must be small.

 

Locking the brake doesn't seem to affect it.

 

At about 12K miles I had play, so I did the whole heat it up thing and retorqued the pivot bolts, following the Clymer manual. I did not detect play after that.

 

It has a final drive leak out of the pinion end (not the tranny; that end is dry). Probably about spoonful leaked out over the course of the last riding season. The leak exited out of the bottom of the boot. I see no evidence of leakage at the hub. I'm guessing that the leak has nothing to do with the play.

 

I looked through the archives here and think that I need to retorque the pivot bearings again. I also watched the F-bomb video and found it very helpful for understanding how things go together.

 

My inclination is that, given the tiny amount of movement, and the general pain of doing the heating, to run it another season (3K-4K miles) then hit it next winter. Or does zero play mean zero play, and I should fix it now?

 

Thoughts?

 

Dave

 

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If you have play then there is probably a few ball bearings that have shifted due to a break in the rivets holding them in uniform position around the bearing.

 

Drain the gear lubricant in the final drive and look for any metallic particles on the magnet under the cap and the color of the gear lubricant. A silvery metallic color to the oil means the bearing is damaged. Still not sure then pull the crown bearing seal and inspect visually. $45 for a new replacement seal.

 

21K is low miles for a crown bearing to go but if the pre-load was not done correctly, the bearing could have failed. Mine lasted for 128,000 miles. Just now in the process of replacing it.

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If the play you felt at 12k went away with tightening the pivot pins then I'd expect that to be where your problem is. My '96 had play in that area when I purchased it (very small amount) and I checked it every week for the first several months of ownership. I rode a lot of miles then and although the play didn't really increase over time I decided to check into the pivots. I found the needle bearing on the inside had created a lot of divots in the race. I replaced these with a set of straight bushings and they have been tight for more than 40k miles. My final drive is still good at 180,xxx miles. Since I bought the bike with 95k miles on it I don't know if the PO had the FD rebuilt or not. Pulling the pivot pins to check them is not difficult and you'll at least know if they are any good or not.

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Morning Dave

 

The VERY FIRST thing you need to do is POSITIVLY determine where the play is coming from.

 

You might need help with someone else moving the rear wheel while you feel around with both hands to see if the play is between the brake rotor & the caliper bracket or IF the play is coming from the entire final drive moving on the pivot pins (or possibly both places)

 

A little pivot pin area movement isn't desired but is usually not an immediate major issue.

 

On the other hand IF the play is showing up between the brake rotor & the caliper bracket then you have more serious problems to deal with (probably the crown bearing getting ready to fail)

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Thanks. I'm going to need to round up some help to check this. I did drain the oil (it was due for it anyway) and the plug was totally free of anything that looked metallic - just dark smeary stuff that I wiped onto a paper towel and checked with a magnifying glass. I'm in the process now of running the oil through a coffee filter (will likely take all day) just to be sure, but the stuff looked just fine.

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Thanks. I'm going to need to round up some help to check this. I did drain the oil (it was due for it anyway) and the plug was totally free of anything that looked metallic - just dark smeary stuff that I wiped onto a paper towel and checked with a magnifying glass. I'm in the process now of running the oil through a coffee filter (will likely take all day) just to be sure, but the stuff looked just fine.

 

Afternoon Dave

 

That is a very good sign but doesn't mean you are home free on crown bearing wear/play.

 

You could even have a good bearing yet, just a bit loose due to normal wear & not enough preload.

 

Next time you drain it (after putting some more miles on the bike) rub that dark smeary stuff between your finger & thumb. If it feels smooth & butter like then that is just normal gear tooth particles. If you feel anything sharp then that is usually a sign of impending crown bearing failure.

 

 

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Well, I got some help and still could not pin down exactly where the movement is coming from. I'll just have to keep a close watch and see what, if anything, develops. Thanks for the advice.

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So if you are having the OEM needle bearings, they "eat" from the bearing race. Since they only move a small amount of degrees, it could happen that you have rotated the inner race so that the needles do not stay in the worn zone in the bearing.

A couple of miles later, they re-seat where they would feel more comfortable, back in the worn zones.

 

Hence you did not feel the play after adjustment and then it came back again ;)

 

Another thing I do not understand (not related to your problem here) is why does BMW make the pins so small. If the diameter of the inner needle bearing is e.g.12 mm, why are not the pins like 12.02? You can easily fit the new pins inside new bearings.

 

It is like they want it to fail!

 

 

Dan.

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