Oil leaks on 1982 R65

[Sava66]

Greetings, all. I was wondering if someone could help identify the source of some oil leaks. Also, if you have had experience with some of these leaks, or level of mechanical ability would it take to fix? The first leak is coming from the engine. The second leak is coming from the drive shaft. If anyone could help me, I'd gladly buy them a beer next time they're in stuttgart, or dig around for some cheap parts. Thanks.

[Barry]

In the first pic it looks like you have a leak from the cylinder base joint. A little bit of misting here is nothing to worry about and not worth the hassle of removing the exhaust, cylinder head and barrel to replace the large cylinder O ring (and of course you would also have to replace all of the other seals, head gasket and pushrod tube seals). If you do want to do all that it's recommended that you also use a thin smear of liquid gasket like Permatex or Yamabond on the jointing surfaces.


The oil on the final drive is coming from the breather. Usually that would only happen if the oil level is too high so that would be the first thing to check.

[Julio A.]

+1 on Barry advice on the leak at the final drive breather.
Check the oil level, Usually if it did not do that before, oil may be travelling from the driveshaft and gearbox and ending up in the final drive.

The leak from the cylinder head would require you pulling the head and installing new seals. Just be careful of putting too much liquid gasket as there are very fine oil passaged there.

[montmil]

You may want to check the torque on the cylinder studs... carefully. Excessive torque can strip the threads in the engine block and then it's cryin' time. 22-23 lbs max and use a calibrated wrench. Do you have shop manuals?

Drain the rear drive and measure the volume of oil that comes out. Replace with the spec amount but no more. Checking the oil level plug at the rear of the drive case is often "iffy". Remove the fill/vent , wash out and check for free air flow while the gear oil is draining.

With some of my old junk, if there's no drips, I wonder if I'm out of oil.

Most thirty-year-old stuff will occasionally drip fluids... man or machine.

[Bob_Roller]

I might add an observation on the final drive top plug .

It acts like a vent to let air out when it gets up to operating temperature .

Just my interpretation of the photo, but it looks like the top 'mushroom' part, is pushed down, if it is, it blocks off the venting feature  .

There is supposed to be a small gap (5mm) between the top part and the wrenching flats

One of our members here Suecanada, found this on her '82 LS a few years ago .

My recently acquired LS's, both had the same problem, looked like a previous owner(s), tapped the top part down with a hammer .

[Sava66]

Barry, I think with my level of mechanical ability, and the fact that I live on base housing, without a garage, it would not be feasible to dismantle the engine to replace the seal. Unfortunately, it's not only a question of looking ugly, it's leaving little puddles of oil (very small wherever I park it).  I recently purchased this bike last month and I dropped it on the third day. I dropped it on the left side and the leak is on the right. Could this seal have been dislodged during the accident? I was only going about 20 KMH. The only other damage was a scraped rocker cover, mirror and turn signal. It'd be helpful to know if this was a prior existing condition or if I caused it.
Montmil, I have the Haynes manual but reading it is like a puzzle because I have to find all the R65 specific stuff. I saw someone on this site had posted some other manuals but I only got access today so I haven't dug them up. What are the manuals that I need as a minimum? Which ones are most helpful?
Bob, I understand where you are coming from on that nut. How would i pry that mushroom upwards to get the 5 mm clearance? How did you fix this with your LS's? I need to read the manual to find out how to drain the driveshaft oil. The most annoying thing about this bike is that I don't really have a list of when the last time any maintenance was done.
thanks everyone so far. I am not going to hit and run. I will keep everyone up to date on my issues and take pictures for future generations of R65 owners.

[nhmaf]

The rear drive vent plug is basically a top "mushroom cap" piece of metal that is just tack welded onto the top of a thin walled metal tube that is inserted into the threaded metal plug that screws into the top of the drive housing.   Rather than trying to pry the cap upward with the plug in place - which OFTEN can result in breaking the cap off and ruining it, it is best to carefully unscrew the threaded base of the vent assembly from the final drive, removing the whole affair.   You can then clean out the vent cap with some brake cleaner or degreaser of your choice (be careful of fluid squirting into your eyes!)    I'd then hold the vent cap/plug upside down, rest the  threaded base part on the jaws of a vise or something to support it, and gently tap downward on the inside tube with a drift or dowel to push the vent tube downward (upward when turned right way around).   The base of the mushroom cap edge should be about 4-5mm up from the threaded "nut"/base of the assembly.  Use compressed air or your mouth to verify that there is airflow through the small punched holes inside the head of the cap to the outside mushroom cap edge.    Then you can just pour your measured amount (I think it is ~ 230cc?, better check) of gear oil into the final drive and replace the vent cap. Just snug up the vent cap assembly and do not overtighten, or you risk stripped the threads in the alloy drive housing.

In case you don't have a printed version, here is a link to a PDF of the R65 owners manual, that may help you out.
http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1271881232

Note that there is a drain plug at the bottom of the silver alloy final drive housing (6 oclock position), and a check/fill plug at the back edge (9 oclock position) AND the vent at the top (12 oclock position).   You drain the oil out the bottom and can fill it either from the top vent or from the 9 oclock plug.   The oil level is full when it reaches the bottom threads on the 9 oclock check/fill plug with the bike on level surface on its centerstand.     THERE IS ALSO A SEPARATE OIL DRAIN AND FILL PLUG PAIR FOR THE DRIVESHAFT - THESE ARE ON THE FRONT SIDE OF THE  alloy final drive housing in front of the shock absorber mount where it bolts up to the black metal swingarm flange.   IT uses the same type of oil that the final drive and transmission use, and while you are doing the final drive oil change you may as well do the driveshaft as well. drain plug is at the bottom, fill plug at the top of course.  Total volume of oil to be put in this location should be between 130cc and 150cc - but I think 150cc is too much.  You can check for the proper level by inserting a small screwdriver tip straightdown into the top fill plug - it will come into contact with the top surface of the drive shaft inside.   The oil level in the driveshaft is "full" when
there is ~1mm of oil on the tip of the screwdriver when inserted from above.

Welcome aboard!

[Bob_Roller]

If you can't get anything between the mushroom top and wrenching flats, remove the plug and see if you can use a punch and hammer to get it to move from the backside .

To drain the drive shaft oil, look at the bottom of the final drive housing at the forward part, there is a drain plug, remove it and the driveshaft housing oil will drain out .

A word of caution on the final drive drain and fill plugs, not too uncommon to find one stripped by previous owner(s) .

Especially the small overflow plug at the back of the final drive housing .

It would be a good idea to replace the crush washer/seals on the plugs when you drain and refill the fluids the first time .

[steve hawkins]

Clean your engine down, especially underneath and then ride it and find out where the oil is actually coming from.  

You could have a leak from your pushrod tube seals  - underneath the cyclinders close to the engine block.

If the oil is coming from the engine gearbox join, and is engine oil (not gearbox oil) then it could be your rear main seal - which will be a gearbox removal job.

Look at the rubber boot on your swing arm, etc.

These are the most common culprits.

Alternatively take a bit of card with you to place under the bike every where you park it.  Or pretend it is a British bike and forget about it.

I repleced my pushrod rubber seals and it still leaks.  But not enough to be bothered with.

Rev Light.

[Johnster]

Is there no "Auto Hobby Shop" at the base where you are ?  every large base in the states has one (run by the AAFES people) and in every one, there is a small staff of hardcore machine fixers that are normally very helpful (but probably not many airhead guys...).

-Tsgt John

[Sava66]

Johnster, You are right. There is an auto-hobby shop on a different base close by. The oil leak from the crankcase seems to have stopped for now. I cleaned up the one coming from the drive shaft and that hasn't been acting up either. When I dropped the bike, it was because a guy cut me off. Now his insurance company sent me a questionairre, so I think there's a chance of getting some money. So I am going to wait, and maybe get it fixed for free. There's a place near hear called Siebenrock. Anyone ever heard of it? It's supposed to be a "Mecca" for airheads (parts, customization, service)

[Sava66]

Thanks for all your advice, I'm going to print all this good info and take it down to the hobby shop and mess around with it. Also, i'm in a holding pattern until I find out if the insurance will cover some of this stuff. In the meantime, it's not physically dripping oil. Do leaks ever just solve themselves? LOL on the British bike snipe:)

NHMAF, you rule! Thanks for your detailed descriptions. I know it probably seems like all of that is obvious, but it was news to me that there is a final drive fill and a drive shaft fill. What I worry about most now are the gaskets/washers/o-rings etc that I need to replace. I am scared to unscrew anything. Does anyone have a list of parts numbers for changing final drive/driveshaft oil?

And that owner's manual is a godsend.

[tvrla]

Siebenrock is very well known. Let us know what you think of the place.

Gaskets and seals will leak when the bike sits for long periods but will seal back up when returned to service. If the bike sits for too long, the seals can harden and go bad, in which case if they continue to leak or suddenly start leaking, they'll need replacing.

[nhmaf]

There are some simple-looking soft metal/aluminum "crush" washers under all the drain plugs on these beasts.  It is BMW's recommendation to replace/use new ones every time, but you can usually get away with re-using the old one unless it is severely deformed.  Sometimes, flipping it the other way around helps.  They are inexpensive (about 11 cents each last time I bought some) and you can find something similar at a local hardware store if you can't find a BMW dealer nearby.  In a pinch, you could use a copper washer of same size.   There are some places that you REALLY do want to use new washers (up inside the bottom of the fork sliders, for instance) because if you re-use one there and it leaks, it is a major nuisance to get back in and re-do the job - but these on the final drive are easy to get to, if you do have to replace them.

[Barry]

I've don't think  I ever had a crush washer leak.  I have the same one on my car sump for the last 19 years. I might of annealed it once but usually just clean it and put it back. The mating surfaces should be intimate by now. I know they are cheap and I should get some but  for me getting to someplace they sell one isn't.

On the airhead washers that just keep the oil in are usually no trouble.  The fork drain screws for example don't need to be metal washers as there is no mechanical load involved. In fact I think the fact that they are metal as stock leads to some stripped threads. Fibre washers would be fine in that application. I've even used O rings with the screws very lightly tightened. No leaks and very little stress on the threads.

As nhmaf alluded I think the big damper rod screws up under the bottom of the forks are amongst the worst culprits because they combine a sealing function with high mechanical load. They stop your forks falling off so have to be quite tight which tends to distort the soft alloy washer.  I think copper would be a better choice than alloy for that reason or perhaps better still a dowty washer which does both jobs better.