Oil leak from rubber gator attached to final drive

[PETDOC]

Yesterday I noticed about a teaspoon of oil on the garage floor below my final drive. I traced it to the rubber gator where it attaches to the final drive. While hunting the source of the oil it became obvious that the zip tie on the rear portion of the gator was missing (have no idea when it left). I everted the rear lip of the gator and no more oil was evident, and none has leaked since (bike sitting for 3 days).
I am assuming that after 30,000 miles a small amount of oil may normally accumulate at this location, and I can replace the zip tie and safely ride to distant locations???
If this assumption is true what is the likely source--final drive or transmission? Is there a pressure related blow off hole from final drive into drive shaft area?

[BubbaZanetti]

it's from the final drive, more likely than not and it's a sign of a bad pinion/bevel gear seal. i've seen a lot of leaks like this on bikes at rallies, etc. you can usually tell by a dark coating of brake dust and gear oil just above where the torque arm connects to the final drive. this is not an emergency situation. mine leaks a bit occasionally, usually just after a final drive fluid change.

[PETDOC]

Derek,
Thanks for the feedback. I usually change my FD fluid every time I change the oil (normally every 6,000 miles) I had just changed it right before a 1000 mile trip to Northern VA and in 2 weeks I am going to Buffalo, NY and back.
Would it be advisable to undue the zip tie every oil change and see if the leak is worsening or can I just totally ignore it?

Dave

[bransan]

Derek,
Thanks for the feedback. I usually change my FD fluid every time I change the oil (normally every 6,000 miles) I had just changed it right before a 1000 mile trip to Northern VA and in 2 weeks I am going to Buffalo, NY and back.
Would it be advisable to undue the zip tie every oil change and see if the leak is worsening or can I just totally ignore it?

Dave

If You change Your fd oil at every oil change, You will start to see some seepage. regular oil will get dirty and some dirt will build up near the seal and prevent oil from seeping past. When it's changed that often the dirt doesn't build up, and as the seal wears it starts to weep. Synthetic oil is much more likely to do this. I change Mine about every other oil change. When I switched to synthetic gear oil it showed a leak soon after. I ignored it and watched the level, it slowed considerably after about 3,000mi. I have just under 30k mi on this bike and just completed the clutch spline lube. I found everything looking good. LOL

[BubbaZanetti]

Derek,
Thanks for the feedback. I usually change my FD fluid every time I change the oil (normally every 6,000 miles) I had just changed it right before a 1000 mile trip to Northern VA and in 2 weeks I am going to Buffalo, NY and back.
Would it be advisable to undue the zip tie every oil change and see if the leak is worsening or can I just totally ignore it?

Dave

i would say it's more a cleanliness issue than anything

chage the final drive fluid every 6K, use 90 or 80/90 weight dino, the 6K check is a great way to keep yourself from being the victim of final drive failure out in the middle of a long trip.

[Andy VH]

I would check for that leak on a regular basis, because if it is the final drive inlet seal you need to change it eventually. But if you keep the fluid up it could go a long time. But if you ignore it and the fluid level gets low you will have final drive bearing problems.

Now, I see no reason to change the rear drive fluid with every, or every other oil change. I mean, you bike, your choice, but a good GL5 80W90 weight oil will last a long time (do NOT use 75W140 thinking it is a better choice). I change my final drive fluid once a season. I do a lot of rain riding. I have used full synthetic GK5 75W90 final drive oil since day one. It never comes out a milky brown color (which would indicate water). No leaks and no grundge. I'm still on the original rear drive bearings, no play indicated.

My 94 R1100RS has 127,000+ miles on it. The only driveline issue I have had is last season I installed a use low miles driveshaft because the original rear u-joint had gotten loose. Oh, and the driveshaft (complete with rear u-joint) from a 1150 WILL fit in place of the shaft/u-joint from a 1100.

[PETDOC]

Now, I see no reason to change the rear drive fluid with every, or every other oil change.

Andy,
I agree with you; however, it is a small amount of oil and by doing it everytime I do engine oil I don't have to wonder when I did it last time. I know a simple record of when I do things would solve that, but it's easier my way--at least for me.

[GrafikFeat]

When you fill up gas do you "top off" or try to round off the numbers to get that last nickel in?
A few drops of gas on rubber in time will look like oil seepage when road dirt is added making it look like an oil leak.
Where does your fuel overflow line terminate? That too could be the culprit.

Jim :whistle

[PETDOC]

Jim,
I do often top it off when going on long trips into nowhere, but this is unquestionably oil (very clean oil I might add), and it came from the zip-tieless gator.

[Wallowa]

I would check for that leak on a regular basis, because if it is the final drive inlet seal you need to change it eventually. But if you keep the fluid up it could go a long time. But if you ignore it and the fluid level gets low you will have final drive bearing problems.

Now, I see no reason to change the rear drive fluid with every, or every other oil change. I mean, you bike, your choice, but a good GL5 80W90 weight oil will last a long time (do NOT use 75W140 thinking it is a better choice). I change my final drive fluid once a season. I do a lot of rain riding. I have used full synthetic GK5 75W90 final drive oil since day one. It never comes out a milky brown color (which would indicate water). No leaks and no grundge. I'm still on the original rear drive bearings, no play indicated.

My 94 R1100RS has 127,000+ miles on it. The only driveline issue I have had is last season I installed a use low miles driveshaft because the original rear u-joint had gotten loose. Oh, and the driveshaft (complete with rear u-joint) from a 1150 WILL fit in place of the shaft/u-joint from a 1100.

Do not want to start an "oil war" but that is a strong statement...what happened to cause you to make that "do not use" statement? I assume a failure while using 75w140?

Thanks..always trying to learn from others experiences!

[GrafikFeat]

Aye sir... Just a suggestion... What is it that you ride?

[PETDOC]

Aye sir... Just a suggestion... What is it that you ride?

'04 1150 GS

[Andy VH]

The comment about 75W140 is based on another lenghty thread about final rive fluids and failures. Our local BMW ON gurus suggest not using it because the much heavier fluid may not actually get between the gear teeth and bearing rollers effectively to avoid spalling on the metal surfaces.

The BMW manual for most final drives suggests GL5 spec 75W90 oil.

[awagnon]

On the other hand, many home mechanics and dealers have used GL-5 75W140 in the FD without any problems. I'm not sure there is hard data either way, but rather some people's impression that anything over 90 weight is bad.

A small amount of oil in the boot is pretty common. I haven't done it, but apparently changing the seal to the input of the final drive isn't easy. Therefore, I believe many people just put up with a small leak. Keep an eye on the FD oil level or pull the boot every so often to be sure. If you can, look up into the paralever to be sure the oil isn't running down from the output shaft of the tranny.