Mistake?

[kmasa]

I was told by my local shop that I can use 75W90 for both my transmission & final drive fluid change...so I did both today. The fluid drained from both the tranny / final drive appeared to have the same color & very similar visicosity as the 75W90. Or, should I go ahead and re-do the final drive?

[smoky]

What kinda bike?

I use the same stuff in both places in my R1200RT.

[kmasa]

2005 R1200GS - almsot 10k miles - I found some write-ups about it but, NOTHING conclusive. I assume either one works fine as long as different oil viscosity doesn't have an adverse affect.

[ben2go]

There is a lengthy in depth discussion on this in the BMW forum.An advanced search should turn it up.

[kantuckid]

Also advisable to avoid syn in FD on the BMW to avoid leaks-well documented as mentioned earlier above.

[AviatorTroy]

Originally Posted by kantuckid

Also advisable to avoid syn in FD on the BMW to avoid leaks-well documented as mentioned earlier above.

Wrong.

[Refplusten]

Originally Posted by kantuckid

Also advisable to avoid syn in FD on the BMW to avoid leaks-well documented as mentioned earlier above.

Please disregard that tidbit of info.

It's one thing to say:

Originally Posted by kantuckid

well documented as mentioned earlier above.

but without the document it's just hearsay.

I'm sure BMW says that Synthetic 75W-90 for the FD is the only way to go. Although SOME guys in hotter climates occasionally use -140 but to each their own. Don't over think it. SYN 75W-90 and you are good to go for both Tranny and FD. I personally use Liqui-Moly 75W-90 full synthetic gear oil. It's a bit pricer than normal gear oil but it's got some moly in there.

[AndyCap]

There are a few documents in the "Hall of Wisdom" Are they "the Gospel"? That's not for me to say.

Hall of Wisdom -> http://advwisdom.hogranch.com/Wisdom/

R12GS Final Drive Fluid Change (From Hall of Wisdom) -> http://advwisdom.hogranch.com/Wisdom...%20Change.html

Final Drive R&R Procedure (From Hall of Wisdom) -> http://advwisdom.hogranch.com/Wisdom...ive%20R&R.html

[GAS GUY]

You can run 75w90 or 80w90 or the 140 weight in syn or dino.

Just make sure it is a good quality oil with gl5 rating.

The most important thing is to make sure not to overfill your FD.

[zitro79]

Yes, make sure that it is GL-5!

[manfromthestix]

Originally Posted by GAS GUY

You can run 75w90 or 80w90 or the 140 weight in syn or dino.

Just make sure it is a good quality oil with gl5 rating.

The most important thing is to make sure not to overfill your FD.

+1 on the above, with one comment. When I lived in Wyoming where it was much cooler, I ran lighter gear oil (same in both tranny and FD) than I do in Virginia. I've run full synthetic for years and never had any issues on three different BMWs so far. I've had two crown seal failures, but both were on bikes with 45K to 50K miles, just wear items. I changed my GS crown seal recently and did a photodoc on it in case you're interested:

http://www.advrider.com/forums/showthread.php?t=806193

The comment - I'm not sure how you overfill the FD unit. IIRC, the manual says fill to the bottom of the threads and that's just about as much as you can get in there without it drooling out. If you were somehow able to overfill it, it's vented and would likely just blow out, right?

Don't overthink this, it's the easiest service you can do on your BMW. I change my gear oils every other oil change, and do oil changes (also full synthetic) about every 5000 to 6000 miles.

Since you're new to the BMW service world, here are a couple more links to things that might be of interest. I've wrenched for decades on my bikes, but I admit to being rather intimidated by the thought of tearing into the BMWs. As it turns out, they are really rather easy to service compared to some other bikes I've had, and you can save BIG money doing it yourself, especially swapping tires:

http://www.advrider.com/forums/showthread.php?t=148614

Check your brake lines!!!

http://www.advrider.com/forums/showthread.php?t=825120


Welcome to ADVrider!

Doug

[kantuckid]

OK, I give . I'll let this go for awhile until you hear from someone that is willing to spend time digging up the "hearsay". In the meantime I'll run dino in my BMW FD to avoid seeping.

[manfromthestix]

Oh yeah, there's one other thing about synthetic - if you get a colored one like Royal Purple or Redline it's really easy to tell if you have a leak!



I've heard of people putting two different colors in the tranny and FD unit so that if one develops a leak they'll know which it was, but that seems like a bit much to me.

Take care!

Doug

[manfromthestix]

Originally Posted by kantuckid

OK, I give . I'll let this go for awhile until you hear from someone that is willing to spend time digging up the "hearsay". In the meantime I'll run dino in my BMW FD to avoid seeping.

If it's seeping, the seal is worn and needs to be replaced. Running synthetic won't make a good seal leak. It's less than $25 and an hour of your time to replace that crown seal. It might be better to do that than worry about it seeping or having it blow out when you're 1000 miles from home.

Doug

[GSA GIRL]

Originally Posted by manfromthestix

The comment - I'm not sure how you overfill the FD unit. IIRC, the manual says fill to the bottom of the threads and that's just about as much as you can get in there without it drooling out. If you were somehow able to overfill it, it's vented and would likely just blow out, right?
Doug

My 2010 GSA does not have a vented final drive. It does not have a fill hole to fill to until it gets to the threads. My R1100GS did but this one is made entirely different. On This model you have to measure out I think it is 300 ml's and fill at a weird angle with a funnel after removing the rear wheel!