Final drive failing?

[ktmdon]

Hey folks, I've read several of the threads here regarding final drives. Here's my situation with my 2008 R1200RT. The bike only has about 25K miles. This model has a final drive drain, and the filler is behind the wheel. The drive is not vented, from what I understand.

After a trip last summer, I noticed just a bit of dirt near the right side seal. Researching the situation, I was somewhat reassured that there was no leak apparent on the inside of the drive, next to the wheel. I purchased a seal and waited for my next maintenance to take care of it.

Weather has been poor here in MI this spring, so I got a late start. I was prepping for an upcoming 8 day trip, and decided to change the seal. It was a little difficult to get the old seal out, but I used the old seal to tap the new seal into place. Everything looked OK. No evidence of excessive movement, noise or rough wheel rotation.

After about a 30 mile test ride, I noticed a drop of oil on the rear wheel. I pulled the seal cover, and saw two areas where the new seal lip had been pushed out. I used a tiny screwdriver to re-seat the bulges, and heard hissing of air escaping.

My final drive maintenance last summer was filling with 180 CC of synthetic 75-90 GL5 oil, so I think I had the right amount of the right stuff. I got about 160 cc back out, no sign of metal contamination.

My fear is that a bearing failure is creating elevated temps and pressure in the drive, and blowing out the seal. My worst case is a catastrophic failure on our upcoming trip, or cancelling our trip.

Looking for suggestions or advice from the many folks here with experience with final drive issues.

Thanks!

 

[Omega Man]

Welcome to the forum!
Kudos on remembering your login information
I can’t really help with your problem but in similar situations I know venting is important.
We have some really talented members that should be able to help you after seeing your question.
Good luck.
Gary

 

[akbeemer]

If you have any moisture in the FD then that can lead to an increase in the internal pressure. You can replace the oil and take a ride and then replace the oil again.

 

[drneo66]

Did you put the seal in dry? IIRC, they are supposed to be put in completely dry. I'm assuming that rotating the FD with the rear brake caliper off the unit doesn't produce any noticeable drag? And, there isn't any play with the wheel mounted at 12/6 or 3/9 O'clock?

Your 180ml fill of oil is correct.

From my other thread - starting with an initial final drive temp. of 75 degrees F, and ending with a warmed final drive temp of 130 F, you'll see an increase of ~3.84 ml for the 180 ml fill.

As Kevin suggested, a good drain/refill and then another couple test rides would be in order.

 

[ktmdon]

Did you put the seal in dry? IIRC, they are supposed to be put in completely dry. I'm assuming that rotating the FD with the rear brake caliper off the unit doesn't produce any noticeable drag? And, there isn't any play with the wheel mounted at 12/6 or 3/9 O'clock?

Your 180ml fill of oil is correct.

From my other thread - starting with an initial final drive temp. of 75 degrees F, and ending with a warmed final drive temp of 130 F, you'll see an increase of ~3.84 ml for the 180 ml fill.

As Kevin suggested, a good drain/refill and then another couple test rides would be in order.

Thanks for the replies, I did lube the seal lips as is my habit with all things dirt bike related. I believe it is possible that I did not install the seal properly. I pulled the replacement seal, the bearing behind looks pristine, is that the 'crown' bearing? Forgive my ignorance, I've not had the time to fully research the topic. I pulled the disc brake, the wheel hub rotates smoothly, and there is no unusual play.

I've seen some reference to a specific dimension for the depth of the install on the new seal, but other videos I've seen on line show folks just tapping them in to clear the snap ring. Any guidance here?

I appreciate the support, it's nice to be back on MOA after many years absence.

-dhs

 

[drneo66]

Sorry - I should have revisited the manual - the RepROM does state to lightly oil the sealing lip of the ring and "use drift to install it until fully seated" - then just install the circlip.

The crown bearing (and someone can correct me if I'm wrong) is the bearing on the other end of the final drive - closest to the wheel, right next to the wheel flange. AFAIK, there isn't a way to inspect this bearing by sight.

 

[ktmdon]

Sorry - I should have revisited the manual - the RepROM does state to lightly oil the sealing lip of the ring and "use drift to install it until fully seated" - then just install the circlip.

The crown bearing (and someone can correct me if I'm wrong) is the bearing on the other end of the final drive - closest to the wheel, right next to the wheel flange. AFAIK, there isn't a way to inspect this bearing by sight.

That's tremendously helpful, the bit about driving until the seal is fully seated. I'm still looking at the parts schematics and on line videos to see exactly how the drive assembly is put together, and how the various bearings are involved in supporting the wheel.

Thanks to all for their comments and patience.

-dhs

 

[akbeemer]

When I replaced one on my 08 R1200R I used the old seal to tap on to seat the new seal. That worked well for me.

 

[ktmdon]

Well, replacing the seal for a second time was all that was needed. I don't believe I had the original replacement fully seated. I used the described method of tapping with a drift, that gave me some feedback when the seal was actually fully bottomed. I guess final drive paranoia set in when I saw oil leaking.

I'm curious as to the factory recommended procedure for removing the seal. I've had issues with the sheet metal screw technique in the past, so I was reluctant to try that.

-dhs