Final drive leak

[evilkevin]

Curious as to what I should look into. As noted on picture a leak(pool) of gear oil(?) on drain screw. The oil gathers and drips from the drain screw, I have found approximately 1tsp of oil dripped out of accordian boot, also clear. I have checked tire and do not notice any play at 9&3 or 6&12. It does not look like gear oil level has gone down noticeably either. 
This amount of build up has been from yesterday. Went for a ride and when I got home, cleaned area as there was build up of oil, so this is from sitting. 
I do not use synthetic gear oil. 

[dirtrider]

14 minutes ago, evilkevin said:

Curious as to what I should look into. As noted on picture a leak(pool) of gear oil(?) on drain screw. The oil gathers and drips from the drain screw, I have found approximately 1tsp of oil dripped out of accordian boot, also clear. I have checked tire and do not notice any play at 9&3 or 6&12. It does not look like gear oil level has gone down noticeably either. 
This amount of build up has been from yesterday. Went for a ride and when I got home, cleaned area as there was build up of oil, so this is from sitting. 
I do not use synthetic gear oil. 

 

 

Morning  evilkevin

 

What motorcycle are you working on? 

 

Your first task should be to determine positively WHERE the gear oil is coming from. 

 

I does sound like you have a pinion seal seep, those do seem to seep a bit on some 1100/1150 bikes (especially when the bike sits parked for a month of more). 

 

Your oil leak could be from that pinion seal leaking into the boot, then seeping down the housing & dripping off of the drain plug. Or some from the pinion seal & some from somewhere else, like the drain plug gasket. Or even from the crown bearing seal then running down & dripping from the drain plug area.

 

Also look to see if some gear oil is blowing out of the top housing vent (that can happen if overfilled, or in cold weather as the thick gear oil bridges the vent hole inside the drive then gets forced out).

 

Clean it up then ride it & look for  where the gear oil is coming from. It sometimes helps to spray on some foot powder as that makes tracing oil leaks more visible. 

 

The pinion seal replacement is a big job on the BMW 1100/1150 motorcycles, doable at home but takes some special tools & some mechanical talent.  

 

[evilkevin]

Forgot to add that it is a 96 R11RT with 44k miles. That is the problem I am having, trying to determine where. 
I find trace amounts between black plastic and metal housing behind accordian boot. Is it from that seal or from inside boot where there is build up of oil and leaking out from there. 
Dirtrider, thanks for the help with the rear master cylinder questions from a month ago. Everyone on this site has been super helpful with novice questions. 

[dirtrider]

1 minute ago, evilkevin said:

Forgot to add that it is a 96 R11RT with 44k miles. That is the problem I am having, trying to determine where. 
I find trace amounts between black plastic and metal housing behind accordian boot. Is it from that seal or from inside boot where there is build up of oil and leaking out from there. 
Dirtrider, thanks for the help with the rear master cylinder questions from a month ago. Everyone on this site has been super helpful with novice questions. 

 

Morning  evilkevin

 

You need to clean it up real good then keep checking after every ride. As mentioned above sometimes spray foot powder can help show the oil traces.

 

If you just can't find it, you can get a bottle of leak detector from  your auto parts store (shows up under a black light) then put a little of that in the final drive gear oil, then check it with a black light after every ride.

 

If you aren't sure it is gear oil then it could even be transmission oil running down the inside of the swing arm coming from the rear  transmission seal. 

[evilkevin]

I would have Hap's Cycle do that job. I can do basic maintenance, I do not have the tools, talent or patience for a big job. 
I will take for a spin and report back in a couple of days. 
Thanks. 

[dirtrider]

16 minutes ago, evilkevin said:

I would have Hap's Cycle do that job. I can do basic maintenance, I do not have the tools, talent or patience for a big job. 
I will take for a spin and report back in a couple of days. 
Thanks. 

 

Afternoon evilkevin

 

If your motorcycle has been sitting or stored for while then the oil seep might go away when you Strat riding it regularly again.