Hi guys:
took my bike to the dealer for the valve and throttle snyc last week. crossed 36k and figured I would let them do it once and seeif there was a diffrence. I already had all the body panels off to do the air filter and the alternator belt. total cost was 100 bucks. Any way the mechanic checked the rear wheel play and told me that it had .16 mm of play and the limit is .5mm
he said i should look into rebuilding the rear end sometime because it will continue to grow. Was wondering if I'm getting snowed on this. Any input?
thanks Miguel

It is difficult to predict when a rear with some play might have a failure. Yours is still within spec, of course. BUT it is true that you MIGHT prevent a more expensive FD failure by a preemptive bearing change.

If it were mine I'd ride and and watch closely. If it increases then I'd go for the bearing change. BUT is important that any such work be done right or its wasted money so you want to know how many of these are done where you've been going.

Are there any other signs of wear like bits in the FD lube that indicates early stage failure? If there are, act now.

Morning Mig

The spec on your 1200RT is up to 1mm measured at the wheel rim with the final drive temp below 95°f.

That .16mm bearing clearance tells you nothing about future bearing demise. You actually want a bit of cold bearing play on the 1200 hexhead.

The 1200 hexhead system is designed around the crown bearing itself controlling the spool preload or play.

Unlike the 1100/1150 system that runs under a preset preload the 1200 hexhead bearing needs a bit of play when cold as it tightens up a bit when up to operating temperature.

My 1200RT failed two final drive crown bearings when new & both were very tight when checked cold. It now has a nominal amount of bearing play when cold & that one has lasted along time.

Check for rear wheel movement on your bike after riding it a while on a warm/hot final drive. At that time bet it tightens up.

thanks for the replies.
I'll keep an eye on the play and check it with a dial indiicator myself after a ride.
My oil is good and clean. I change it every 2 tire changes and the spline area is well lubed.
thanks

Just playing devils advocate and maybe I'll learn something ...

What would make it dirty?

Motor oil is designed to suspend combustion contaminants and shows it by changing color. It's for sure a sign things are working right and not at all a sign the oil is "worn out."

But what contaminants are there in a rear drive?

Methinks if there are contaminants there's a seal problem rather than an oil problem.

Yes, there is "breathing" and it's just SOP to check the oil should there have been an encounter with lots of water that could have entered via breather. Wouldn't wait for "2nd tire" to make that check. Otherwise, don't see much reason to vary from BMW change specifications.

Afternoon Kent

Gear oil suitable for drive axles usually contains a lot of Moly type additives & those by nature turn the oil dirty looking in short order.
So, some drained gear oil's can look dirty but still be perfectly fine.

Some of the gear oils (like the BMW Super Synthetic & some other up-level synthetics don't seem to discolor like the older hi moly conventionals so those can be contaminated & really not show it.

The main things that seem to contaminate BMW final drive gear oils are Moisture, Metal Particles from gear tooth contact wear, & heat.

The 1200 hexhead have no vent on the final drive (sealed units) so any moisture that finds it's way in through seal intrusion or other means usually stays in the drive until drained.

Does the camhead final drive have a vent? I thought I heard that it did change somewhere along the line? and if so.. where is the vent? I have a 2010 and would like to know if mine has one?

Afternoon Phil

Supposedly the F/D vent was phased in sometime early 2010 (production wise) but when they actually started appearing in the actual bikes I don't know.

DR, do you know where it is at? How to identify the vent?