Final Drive - do these pics show the symptoms of a problem?

[cb75076]

Here is a pic of the magnetic drain plug (close-up, so perhaps larger than real). Next pic is the old (used) fluid, which is cloudier and a bit darker than the new bright red stuff. I sprayed the magnetic drain plug with electronic parts cleaner so you can see the metal flakes. The flakes are black - the angle of the bright sun reflecting on a few flakes may make a few of them look shinier than they are. This is with about 4000 miles on the old fluid. So, do the drain plug and old fluid look about normal? The bike is a 1996 R1100RT with 85000 miles on it. The trans and final drive fluid is normally changed at every 6000 miles. There is no play at the rear wheel (3-9, 6-12 positions.)

Thanks,

Jerry

[cb75076]

Here's the pic of the old fluid.

Jerry

[PETDOC]

Jerry,
Not sure if my comments are of any help. I've got an '04 1150 GS with 44,000 miles. I change the read drive fluid every 6,000 miles and all I have ever seen on the drain plug magnet is a small amount of fine grey mush. I always wipe it off with a shop towel and then pass another magnet over/through it to see if any pieces are picked up---none to date.
Dave

[ragtoplvr]

The flakes are big enough to be a concern. At your miles you certainly could have bearing wear out occurring.

If it were mine, and I did not plan any long trips I would do as I normally do, check for slack every week when I check and adjust tire pressure.

If I were planning a long trip, I would change the bearing first.

WARNING, this is only what I did. I can not recommend it, and if you have a problem do not sue me, OK. If you can not abide by this then take to a dealer.

I did it with the drive still mounted to the motorcycle. On Mine the original bearing was SKF and so was the replacement. Bearings are usually very consistent.

The solder method below is what I call a reality check. IF you end up close, then probably OK to reassemble. If there is a big difference, something is wrong. It is not the BMW way, and I am not responsible for the result if you choose to use it. It is simply what I did.

I used ring of wire solder a bit thicker than the shim. Assemble without o ring and seal, torque bolts, rotate thru one turn, then disassemble. Use calipers to measure thickness of solder, you can cut the solder ring so you measure the compressed part if needed.. Solder has no rebound. I measured several places, they were the same. Then get the next size thicker shim and trial assemble again, no solder, use the shim. Mount up the wheel and check for slack and free, Mine felt good. I used the same thickness of shim. If it is a big shim thickness difference, then you may have did something wrong. You should then get someone with the right tools to refit it.

then you can put in the shim, seal, oring and assemble for good. use only 90 Wt or 75W90 only no 75W140. I do not think the weight makes a difference BUT why take a chance.

Mine failed at about 35K miles, I replaced using solder to verify shim. I am at 57K miles now, still no slack no fuzz. If it lasts until next year I know I did not do any worse than BMW with the reassembly.

Repeat, this is only what I did, and your results may vary, so if you choose to try it it is your decision, and do not sue me for bad advice, this is not advise.

Rod

[jingdog]

You gotta go by play in the rear wheel. I see nothing wrong with the oil or the drain plug. My 96 R11GS has 108k on it now and the FD is fine! (course the transmission was replaced at 66k) I keep an eye out for oil on the rear wheel (a pretty serious problem) and check the play before and during trips. BMW quality control problems are shaking everybodys monkey tree!

[riderR1150GSAdv]

Looks like the bearing is going out, but an inspection will reveal that for sure. Take the FD apart and clean the innards. See if any rivets are missing form the cage containing the balls.
Check the bearing race for pitting using a magnifying glass. If you spot any imperfections, go ahead and replace the bearing. You can alway take the FD by itself to the dealer if you are unable to do the work yourself. YMMV

[GSAddict]

WHOA Gentlemen!!
The Black flakes are normal, I see them on every drain plug I have pulled.
It's the SILVER flakes that are the warning. In my on case twice, accompanied by a 'grumbling' when turning the wheel on the centrestand. (the third time I checked and reduced the shimming)
Refill with oil and ride!
Put the worry beads away. ;)

BTW: ragtoplvr - I like your idea with the solder! Good thinking. I had to remove the drive and get fancy to calculate mine. Can I ask you what diameter of solder you started with?

[nrpetersen]

I'd be concerned that a full circumference solder ring would apply excessive preload to the bearing. Maybe just use say three equally spaced lengths of say 1/2 inch or so of small diameter solder.

The technique is a good one I'd say, but the amount of preload that is applied with a full diameter ring would probably be excessive. The preload force isn't specified by BMW (they spec a dimension which I think is wrong) but the necessary force is probably well under 1000 pounds.

FWIW I think I'd plan on replacing the bearing this winter, although the debris shown doesn't look too bad.

[ragtoplvr]

I was using good old kester 44 cored solder, which I have quite a selection of diameters. I chose one very close to the thickness of the existing shim. and it tested a similar length on a 1 ton arbor press, and it squeezed to a smaller thickness than needed with very little force, probably not even 1000 lbs.

If you used a bigger solder, then 3 pieces held in place with grease would be a good idea. IN my case the solder wire was pretty small, and I thinned it out only a tiny amount.


YMMV

Rod

[nrpetersen]

That should be a good indicator assuming the length under compression is roughly the same.

Actually it is probably better if the length under your press test is similar to the circumference of the bearing as then there will be no warping deflection of the race next to the solder. Otherwise the three short lengths could have a measurement error due to the race coming out of plane.
NRP

[cb75076]

Thanks for everyone's thoughts. Here's an update: It's been 1500 miles since I posted that picture of the drain plug. I'll be doing some extended travelling over the next weekends, so I removed the magnetic drain plug again, to see how things look. The drain plug had maybe 3 or 4 very tiny metal slivers (sort of that Christmas tree fuzzy-looking stuff), and that was it. The red oil looked a tiny bit cloudier than originally. Just to see if it makes any difference, I changed from the BMW dealer's 70(?)-140 Synthetic (red) to the BMW dealer's GL5 80-90 Hypoid gear oil (yellow).

Jerry
NJ

[DHunt1150]

The gray/black 'fuzzy' stuff on the plug is normal. Rub it between your fingers - if it feels 'gritty' and rough, then you should consider a rebuild. Only us the recommended viscosity, not the 85-140 stuff. 90K+ on my 1150 and going strong

[tgf429]

Picture looks kind of suspicious. When I change my final drive fluid and put the plug down some oil remains on the plug and gravity makes it accumulate in the crevice of the plug. This plug looks as if it has been wiped and then possibly contaminated with something.

[kootenaykid]

With that many miles just do the bearing and seal. Its not expensive at this point and is easy to do. I did mine this summer on the road at a picnic table after I got the parts shipped to me on the bus. Its really not a big deal.

[RoboRider]

Rod and Kid,

I'm very interested in the bearing work you did. I do all my own work and so I have a couple of questions.

About how much were the parts (bearing, seal, etc.?)

Were these BMW parts or can you get the bearing from a supplier.

Kid: what did you do to measure for the shims?

Nothing else in this drive needs R&R while in there? Just the big bearing? Isn't there another bearing somewhere?

Thanks,
Rob

[ragtoplvr]

I used bmw parts. Local bearing suppliers wanted from $250 to $450 for SKF 3C bearing, BMW was about 150 ish for bearing, seal, oring and seal washers. I could get different brand bearing for less, not worth it to me. I have given up on the concept of saving money riding. Gas would need to be over $5 a gallon for that to happen.

My pinion bearings seemed good. The tapered roller bearing on the other end was good. So I needed not other parts.

I expect most of the time your other bearings will be good. If you do not inspect the drive for slack pretty often, and you let the bearing totally fall apart, that much metal in the oil can not be good for the other bearings. I check for slack at least once a week when I check the tire pressure and oil level.

Rod

[MOTORBIKE]

After reading of all of the problems with the final drive.I have got to point that i have parked my 1100 RT, and ride my ST1100 Honda. That i dont have to worry about.

[kgadley01]

I would wait to see if Paul Glaves sees this post. I would take his advice to the bank...