Motor oil in gear box

[Guest]

My friend has discovered motor oil in the gear box and is looking for some insight into how to approach this. He is considering pulling the engine and splitting the case to see what is wrong. Are there any less drastic things he can do before he resorts to this?

[recycled64]

Your thread begs a couple of questions-is the bike in question yours, or his, and if it's his, what bike is it?

[Tamara]

Your thread begs a couple of questions-is the bike in question yours, or his, and if it's his, what bike is it?

It's his. His is an '82 GS1100L shafty.

[Steve]

It should have GEAR oil in the secondary drive area, if that is what you are calling "gear box".

The term can be a bit confusing because "gear box" is also used to describe the transmission, which is, indeed, lubircated with the same engine oil from the crankcase.

The secondary drive area (which is a separate reservoir) and the final drive (at the rear wheel) should have gear oil, which could be called "hypoid" oil or GL5.

Now this raises another question: does he know for sure that only gear oil was installed there? Or is he draining it and finding that engine oil is in there? Does it appear to be a mix or oils or does he suspect that engine oil is migrating into the secondary drive area?

.

[Tamara]

It should have GEAR oil in the secondary drive area, if that is what you are calling "gear box".

The term can be a bit confusing because "gear box" is also used to describe the transmission, which is, indeed, lubircated with the same engine oil from the crankcase.

The secondary drive area (which is a separate reservoir) and the final drive (at the rear wheel) should have gear oil, which could be called "hypoid" oil or GL5.

Now this raises another question: does he know for sure that only gear oil was installed there? Or is he draining it and finding that engine oil is in there? Does it appear to be a mix or oils or does he suspect that engine oil is migrating into the secondary drive area?

.

He drained and replaced all the fluids when he bought the bike back in April. He said what he found in the secondary drive was definitely motor oil mixed with the gear oil. He's a pretty good mechanic and is pretty sure that one of the seals has gone bad. I just wanted to run it by you guys in case there is something simpler causing the issue.

[Nessism]

Going to have to split the cases if the two oils are intermixing. Good bit of work there, but fun.

[matt1100]

Been there, done that, did a thread about it. Lotta work, you can do it with the top end still on, check bearings while your in there. Be careful indexing the gear clips when reinstalling the cam dog. I got to do it twice due to this

[tkent02]

Before doing all of that I would make sure, by draining it all and refilling it. Ride it and see if it intermixes again. Just to make absolutely sure someone (maybe even me) didn't accidently pour some of the wrong stuff in the wrong hole.
Been there, done that, too.

[Tamara]

Thanks to everyone for their insight on this!

[bbjumper]

Tamara,

Tell your buddy, I feel your pain my man.

I went through that just last June. I was not looking forward to a complete engine teardown and like you I would have rather had a root canal that do that work. I had just done a top end refresh the year before and with the exception of the secondary drive seal problem the Zook was tip top mechanically. I ride my GS, allot, over the last three years I've ridden it 25k or so, and that was while I was pretty much doing a rolling restoration.

I documented my work here,

http://www.thegsresources.com/_forum/showthread.php?t=209765

I admit once I got down to it I really enjoyed the experience. Although these old GS's are amazing motorcycles I don't think the designers had any idea there would be such a cult following after thirty plus years and this many bikes still on the road. With a good amount of TLC they will virtually last forever. To do that you will eventually need to replace "all" of the rubber parts in the engine, seals, o-rings, gaskets and such. After so many heat cycles they eventually just break down.

I couldn't be happier with the results, the bike runs like new, I figure it will last longer than I will now. I just did another round trip to see family in San Diego two weeks ago, 900 mi in three days, traveled through undoubtedly the worst weather I have ever ridden a bike through, thunderstorms, lightning, rock slides, flash floods, rained so hard I could see maybe 30 feet in front of me at times. I took this once I got on the other side of it.

The Zook never missed a beat and ran perfectly.

Once your sure of the problem my recommendation would be to tell your Buddy to bite the bullet and do the work, what you end up with is a truly classic ride that you can ride anywhere with confidence.

Cheers

[Tamara]

Gorgeous picture! He's going to bite the bullet and do the work. He loves his bike and wants to do right by it.

Tamara,

Tell your buddy, I feel your pain my man.

I went through that just last June. I was not looking forward to a complete engine teardown and like you I would have rather had a root canal that do that work. I had just done a top end refresh the year before and with the exception of the secondary drive seal problem the Zook was tip top mechanically. I ride my GS, allot, over the last three years I've ridden it 25k or so, and that was while I was pretty much doing a rolling restoration.

I documented my work here,

http://www.thegsresources.com/_forum/showthread.php?t=209765

I admit once I got down to it I really enjoyed the experience. Although these old GS's are amazing motorcycles I don't think the designers had any idea there would be such a cult following after thirty plus years and this many bikes still on the road. With a good amount of TLC they will virtually last forever. To do that you will eventually need to replace "all" of the rubber parts in the engine, seals, o-rings, gaskets and such. After so many heat cycles they eventually just break down.

I couldn't be happier with the results, the bike runs like new, I figure it will last longer than I will now. I just did another round trip to see family in San Diego two weeks ago, 900 mi in three days, traveled through undoubtedly the worst weather I have ever ridden a bike through, thunderstorms, lightning, rock slides, flash floods, rained so hard I could see maybe 30 feet in front of me at times. I took this once I got on the other side of it.

The Zook never missed a beat and ran perfectly.

Once your sure of the problem my recommendation would be to tell your Buddy to bite the bullet and do the work, what you end up with is a truly classic ride that you can ride anywhere with confidence.

Cheers

[Tamara]

Wish us luck! We're cracking the case on the 1100 tomorrow to see what's what with the oil going where it shouldn't.