Something to worry about?

[challey]

After a relatively short ride (~90 miles) this past Sunday, I decided to try and clean off some of the winter crud from my Beakster. As I looked over the bike before starting cleaing in earnest, I noticed a black film on the FD housing, just behing the rubber boot covering the driveshaft. The film is oil of some kind but I can't tell whether it's engine oil or gear lube. You can see in the picture that the film is primarily on the mount for the torque arm but there was also a little on the top of the FD case. There is no discenable decrease in either the FD or transmission fluid levels and there is no oil stain on the ground where the bike has been parked.

Any thoughts on what the leak is. Is it something I need to find and eliminate right now or do I just wait and see what happens?

Charlie

[Boxer]

Charlie,
It looks like the lube is seaping past the inner seal and then it migrates out past the boot in a fine spray. Doesn't look like too much to worry about, unless you see actual wet droplets down at the bottom. Then it has begun to leak faster. I'd just keep an eye on the FD fluid level.

[Biff's R]

+1 to what Boxer is saying.

[OU812]

Is your rim getting dirty? That was how mine started.

[challey]

Is your rim getting dirty?

The rim was dirty but it has been a good 6 months since it was cleaned - the front was pretty dirty too.
I think I'll take the rubber boot off if the temperature gets over 45 this weekend (no garage) and see if I can locate the source more precisely.
Thanks for the suggestions guys.

Charlie

[towerworker]

Charlie,
It doesn't take much oil at all to make a big mess. Mine seeps a little but the level never seems to drop. The telelever housing is a dry housing so for certain the oil is coming from the FD.

Can I say "they all do that?" or maybe "alot of them do that!"

Wayne


fwiw--I don't think BMW quality is what it once was.

[boxermania]

Wayne is correct is just a bit of seepage, nothing to worry about. Just clean it good and keep your eye on it. Another example of Teutonic interruptus engineering. Yes....everywhere you look there is something to keep you interested........

[Croc]

Mine did that!! Pulled the boot back, cleaned out any oil with an absorbent cloth and replaced and have done about 15000 miles since and not had any more other than very, very minor seepage. No noticeable fluid loss either. I think it happened shortly after I switched to Full Synth in the FD. I assumed that the synth oil was more slippery and just seeped past the oil seal but seems to have settled.

Croc

[wncbmw]

Mine also did that. Next oil change, i drained the FD oil back into my measurement cup and it had precisely the correct amount in it and looked clean to boot! So I quit worrying about it.

Of course, as you know, I did eventually have a FD bearing failure but it had nothing to do with the leak and I had some warning. BTW, if you drain the fluid and it shows metal, then you worry!

Oh, and I am switching the FD back to dino 75-90, just in case. Used 75-140 syn for one or two changes.

[OU812]

Is your rim getting dirty? That was how mine started.

Mine was using FD fluid at the rate of 1/2 the capacity every 200 miles. Traded it in.

[CycleRob]

challey,

In removing my FD's boot I found it would slip off it's mounting grooves with not too much force in the 3 & 9 OClock positions. I was trying to avoid damaging the boot while cutting the ziptie, so that's why I tried that removal method. Too my surprise, after removing both ends and cleaning away the inside, the boot can be slipped right back on, both ends, re-using the same original very long zipties. Study the mounting grooves and use the blank sections, where the is no cast in ziptie retaining ridge, to slide the tight zipties and boot off or back on together. Before you do anything, note where the boot seam is to locate it properly going back on.

This little trick will make removing the boot for inspection/cleaning a lot less of a hassle and zero cost.

[challey]

Thanks for suggestion Rob - would be a lot easier to just slip things off than it will be removing and replacing zip ties.

It seems that one common thread may be the use of synthetic gear lube (I used Red Line 75W90). I planned to switch back to conventional anyway since I am out of Red Line. I've been changing the FD fluid at each crankcase oil change, just to keep an eye on things given the numbers of FD bearing failures.

So when the weather warms a little, I'll remove the boot, clean up everything and change the fluid. Right now, we have the famous SE PA "wintry mix" which is snow, sleet and rain mixed together. Things don't look promising for this weekend but Spring is right around the corner.

Thanks again to all.

Charlie

[towerworker]

I think I will look into a "chain drive conversion" for my R. (and a wet clutch)!!

[mvscorpio]

Mine did exactly the same thing, started at 24K miles. Never seemed like much to worry about, but had dealer check (and document that I had them check) at 24k service, and again at around 35-36K. At 40K, the leak got worse and diagnosis was rear main seal. Replaced under warranty since I had the service checks documented. While they were in there, they replaced FD which showed wear.
If you are still under warranty it may be worth the effort to have them check and document it.

[rdsmith3]

Mine also did that. Next oil change, i drained the FD oil back into my measurement cup and it had precisely the correct amount in it and looked clean to boot! So I quit worrying about it.

Of course, as you know, I did eventually have a FD bearing failure but it had nothing to do with the leak and I had some warning. BTW, if you drain the fluid and it shows metal, then you worry!

Oh, and I am switching the FD back to dino 75-90, just in case. Used 75-140 syn for one or two changes.

Why the switch back to dino oil for the FD and transmission? I a just about to do this fluid change, and I was going to buy synthetic.

[challey]

Bob asked:

Why the switch back to dino oil for the FD and transmission? I a just about to do this fluid change, and I was going to buy synthetic.

At the WI rally in 2007, Paul Glaves recommended using dino in FD and synth for the trans. His reasoning was that, unlike the trans, the FD does is not highly stress and does not run particulary hot so:
1) it doesn't benefit from the added protection of synthetic and;
2) dino provides more lubrication protection during the critical period when you first start up (he claims that since it is more viscous, it "sticks" better to the FD ball bearings and prevents metal-to-metal contact when starting from cold).

Don't know if the recomendation really provides much benefit, bu I plan to switch back to dino for the FD only at the next change - wanted to use up my Red Line first.

Charlie

[rdsmith3]

But is there some correlation between using synthetic FD oil, and FD failure?

[challey]

Yes, according to Glaves.

He said he sees more premature FD bearing failures where synthetic gear lube is used but didn't really present any supporting data.

[priapismic]

But is there some correlation between using synthetic FD oil, and FD failure?

If you read his series of articles on this subject in the BMW Owners News, he (Glaves) advises against using 75w-140 specifically. He feels that this weight is just too thick for the final drive. It's not so much the dino vs. synth that is the issue, it's the weight - and the 75-140 stuff seems to always be synthetic. If I recall correctly he had some statisical correlation to the weight of the oil used in the FD.

After reading his articles, I change my FD oil with every engine oil change, and always use the 80w-90 viscosity. So far no sign of metallic shavings on the FD drain plug, and I just turned over 60,000 miles.

[rdsmith3]

I went to Advance Auto yesterday to get some gear oil. The selection was pitiful. They were cleaned out. My choices were Mobil 1 Synthetic 75-90, or Coastal brand dino oil. So I went with the high-priced Mobil 1 synthetic.