The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Jim_Rillie_R65LS on July 03, 2007, 09:15:06 PM
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Hi all,
First, as one may notice from my ID the bike is an OCT 81 manufactured German bike, once owned by Sue (Canada). Now by me since 2003, from Sean Doran who probably bought the bike from the guy who bought he/she from Sue, who got he/she/it from a Canadian dealer as a trade in. I could be wrong, but I think that is the history of this one, here.
My rear end looks like it needs to be replaced to me, and I'd love a second opinion.
That end leaks outside and inside on the brake shoes.
All or most of the oil seals in the area have been replaced by my mechanic with my assistance.
The 4 O Rings for the brake shaft have been replaced several times per year with various placements of the big washer (in or out)
No change, it still leaks. I get about 700 kM before the back brake shoes start to slip again due to lube, and the garage floor and rear tire get drops per night, a good 1.5" spread in about 3 or 4 days..
I determined that there is no migration of gear lube from the drive shaft to the rear end.
Any ideas ? I would dearly love a simple fix , but what are the real options to solve this?
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A lot of the time leaks like this are aggravated by a groove worn into whatever the seal rides against in the spot contacted by the seal. Just replacing the seal puts it riding in the same groove with the same leak. I have never really looked at the final drive seals but most of these type seals (timing chain cover crank seal on car motors comes to mind) can be re-seated to a different depth upon re-installation causing the seal lip to ride on a "fresh" surface.
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Oh my poor baby bike is dribbling in his old age! Ownership chain: I bought it in a private sale from the first owner who was a young German fellow, Ulrich Rademacher, who actually brought the bike with him upon coming to Canada. He wanted to return to Germany so wanted $$$$ and sold the bike to me for $5900.00 CDN back in 1984. The bike was spotless and had a neat German language owner's manual which took some doing to work with. I don't think I even dickered on the price as I was so smitten with the styling and red with white wheels look. I sold the bike to Hugh Morrison and he sold to Sean Doran who sold to Jim.
Jim, I have no ideas for you...just that I get the final drive oil flung about on my rear wheel during longer hot fast rides. I see you keep changing those O-rings on the brake actuating arm as well. There is a tube thingy we can retrofit over that arm I understand but don't know much about...I read it on Boxerworks or airheads probably. I don't get dripping oil as the bike sits though.
Can you ascertain the source or even drip point for the outside leak?
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Jim , you only mention the brake shaft seals. Has the output shaft oil seal on the rear drive cover been replaced yet ? You may want to try looking the cover plate over with a 10 power magnifying glass to check for cracks.
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This may be a dumb question but is there a "vent" on the top of the rear drive of that bike? Is there a way to see if it is blocked? If it is blocked then the rear drive maybe pressurizing as it gets hot and causing leaks? :(
Just a thought.
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I've been trying to sus-out the same problem, but so far haven't figured it eihter. Just went to Duane Ausherman's site (http://w6rec.com/duane/bmw/finaldrive/index.htm) He talks about a weep hole next to the drain plug, apparently that gets blocked. Anybody tried that one/had any success with clearing it?
Course that wouldn't solve the excess oil getting in there...Urg. Late night logic...
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Aparently the drain hole is only on the early (rounded) rear drives the The square/ribbed ones of the '81+ models aparently don't have this hole. (?)
Funny thing is I have the drain hole but my rear drive doesn't leak. (Yesh!)
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This may be a dumb question but is there a "vent" on the top of the rear drive of that bike? Is there a way to see if it is blocked? If it is blocked then the rear drive maybe pressurizing as it gets hot and causing leaks? :(
Just a thought.
The filler cap is also the vent. You should be able to blow through it with your mouth when you take it off.
I think you would be right about pressurizing if it was blocked.
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Grumble... and now MY rear end is starting to dribble oil, in empathy, or perhaps it is catching....
:o
Well, at least my bike just started doing this AFTER I bolted in the rebuilt clutch and tranny, but BEFORE
I bolted the driveshaft onto the output flange on the transmission - so at least it managed to time
this incident pretty well. Since I'm heading off to the West Bend rally this week, it'll be yet another week
before I can look into it, and get her back on the road !
::)
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The filler cap is also the vent. You should be able to blow through it with your mouth when you take it off.
I think you would be right about pressurizing if it was blocked.[/quote]
That tastes gross. But it's a quick easy test.
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Only if you are running synthetic.
Now if you are still using, dino, maybe a nice blend of 75-90, what could be better... ;D
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All vents are OK, and the Cardan seal was replaced last year with no appreciable difference. There is also no migration from the
driveshaft to the rear end.
Jim
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Only if you are running synthetic.
Now if you are still using, dino, maybe a nice blend of 75-90, what could be better... ;D
Oops! Guilty. Amsoil for me.
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All vents are OK, and the Cardan seal was replaced last year with no appreciable difference. There is also no migration from the
driveshaft to the rear end.
Jim
So Jim, all your leaks are definitely only from the brake actuator shaft? Any wear in the bore where the O-rings reside? Would wrapping a bit of thin wire in the O-ring grooves first before rolling in the O-rings provide more pressure? Get a machine shop to add an extra O-ring groove? (My '81 G/S originally only had 2 grooves, I had more put in)
The problem is, it was previously owned by Sue, and I have seen a picture of her on her bike (Can-Am) in her youth. She probably used all the brakes to maximum potential while in her tear-away youth. [smiley=undecided.gif]
Chris
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If you have confirmed that the brake shaft seals are causing the problem, you could try getting thicker o-rings in place of the OEM seals. Most auto parts stores have a selection of o-rings, and they should all be oil compatible.
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Nhmaf and Jim Rillie: Did either of you figure out where the leak was coming from and what did you do to fix it? Since I was at the West Bend Rally as was Nhmaf, I forgot to follow this thread. Now I see that there was no solution. I get oil on the wheel rim on the rear when on long hot runs. I never thought of using a wider brake actuating arm Orings or having another Oring groove cut by a machinist. Hmmm. Guess I better deal with all the seals anyway.