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possible rear engine seal leaking oil

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Darryl.Richman
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possible rear engine seal leaking oil

Post by Darryl.Richman »

$500 doesn't sound outrageous to me to replace a rear main and oil pump O-ring. Your dealer probably charges in the $75/hour range for service (it's more expensive here in the bay area!), and this sounds like he's charging for about 6 hours of labor.

I don't quite understand why the dealer thinks the cost should double if you need a clutch, when it takes essentially the same labor to get to the rear main seal.

You can do this job yourself, if you're mechanically inclined, in a weekend. If you don't already have it, you should consider getting a Haynes manual for your bike. Then you can read through it and decide whether you want to take this on.

If you don't notice the clutch slipping, you may not need one. I see that Max BMW offers them for $125 (they have a great online parts fiche).
--Darryl Richman

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schrader7032
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possible rear engine seal leaking oil

Post by schrader7032 »

It's mostly big pieces, so it's definitely something that's doable at home. A few suggestions or cautions:

- block the crankshaft from moving forward. It's pretty easy to do and could save from having to disassemble the engine.
- relieving the pressure of the clutch spring is something of a trick but simple when you think about it. The aftermarket manuals probably have examples. There are six screws that squeezes the parts together. After removing three of the screws, insert long threaded bolts with nuts and washers. This lets you hold the pressure while the last three screws are removed and permits a gradual release of the spring pressure.
- observe how the various seals are installed once the flywheel and oil pump cover are removed. You'll need to put the seals back on to the same depth. I think some use some PVC pipe as a drift to get the rear main seal installed evenly.
- probably should consider replacing the seal on the input shaft to the transmission. You're there and this would be the time to replace it. Rear main seals probably don't contaminate the clutch, unless it gets real bad. A leaky tranny input seal or oil migrating forward on the clutch rod are more prone to oil up a clutch.

The flywheel bolts take some pretty good torque IIRC, so you'll need a good torque wrench. Probably some blue loctite might be called for on some of these bolts. The last thing you want is for them to back out at a later date.

That's it! Well, sort of, but it's doable... :)

Kurt in S.A.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

khill
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possible rear engine seal leaking oil

Post by khill »

I think the service manager was thinking of replacing all the clutch
components including the pressure plate but I'm not real sure. Now for
the new update on the leaking rear seal. I took it out for about a 20 mile
ride and was riding at 70 mph a big part of the time so to keep the rpms
up and when I got back home I put the bike on the center stand and it
took about 5 to 10 minutes before I witnessed any oil dropping to the
floor. I think the oil pressure sending unit did a big part of the job
but there is still a little bit coming down the back side of the shelf. I'm pretty mechanically inclined but I only have some of the tools. I have
found a guy who has been recommended over in Lubbock, Tx and he
said I could watch and ask questions while he works and possibly even
assist. This would be great for me but I still have to take my bike approximately 400 miles to do so. This person was at the ride in at
Deming a few months ago so you might know him Darryl but I'm not
sure. He seems to have a lot of experience working on the old airheads
and he owns a newer oilhead. Now that the amount of oil ;leaking seems to have dimished it might be prudent to wait for a little while longer but
I don't really like even one drop of oil on the floor. I don't think the clutch
is slipping at all but I'm sure it has some wear on it. Possibly just replacing disc would do the trick if this is proper protocol on the older
beemers. I will have to say after riding the bonneville classic I didn't
realize how much vibration my R65 has. I guess it's the technology
change.

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schrader7032
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possible rear engine seal leaking oil

Post by schrader7032 »

Darryl can speak to the vibration levels on an R65...they did tend to be buzzy, IIRC.

You can have some of the pieces measured in the clutch to see what needs replacing. But if you're having someone else to it, you'll need to have all parts on hand, just in case. Plus sometimes it could be penny wise, pound foolish to not change everything. Once you're in there, it probably would be best to change it. But then, I just went through this on my R69S with 30K miles on it...I just roughed up the clutch plate and reused everything, but everything looked fine. If you watch and see how things are done, maybe then, if you decide to change things later, you could then do it yourself.

Kurt in S.A.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

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Darryl.Richman
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possible rear engine seal leaking oil

Post by Darryl.Richman »

The R65 had a reputation for being buzzy around 4000 rpm, which corresponds to freeway speed in 5th gear. Frankly, I never noticed it, but I was a total n00b then, and nobody told me it was supposed be smoother than that. Sort of like Wile E. Coyote, who can keep on running until the clouds dissipate under his feet and only then does he realize he's standing on a 1,000 feet of air. Anyway, I "ran" on air for 56,000 miles.

I do recall that there was a "fix" that was published in the BMW MOA magazine, wherein the front engine spacer was replaced by a slightly modified engine mount for some Chevy. The mount had a steel inner sleeve bonded to a rubber bushing. The idea was to partly rubber mount the engine and not transmit quite so much vibration to the frame. I have no idea if this worked or was even a good idea.

The reason to replace the rest of the clutch pack is because it has been overheated and it's warped, or the diaphram spring is old and weak. Oil will ruin the clutch disk friction material, but all you have to do is clean off the other pieces with brake cleaner.
--Darryl Richman

khill
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possible rear engine seal leaking oil

Post by khill »

This vibration was at lower rpms and perhaps I was lugging the engine
a little to much. We were at slower speeds (about 35 I think) and I noticed I was around 3000 rpms which might be to low and I might have
been really lugging the engine to much. another thing that I am being
told often and by oilhead riders and BMW service managers is I should
really think a lot about taking longer rides on such a older bike. I was
looking at other brands because to my knowledge BMW doesn't make
a newer bike that has a low enough seat height for me except possibly
the F650. Since I do mostly street/interstate riding I really don't want
a dual purpose bike. I guess it all depends on how many of the old parts
have been replaced on my bike. A friend of mine rode down into the
heart of Mexico on his R80 only to get back in town and the next
day the diode board gave out. He now has his bike up for sale. maybe
newer bikes have some of these same problems. I guess the alternator
rotor is another big problem spot for older airheads.

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schrader7032
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possible rear engine seal leaking oil

Post by schrader7032 »

Sounds like you're really at a crossroad with your bike. It's got some things that you like but there are still the unknowns about it. How much farther do you keep investing? Maybe the next couple of "fixes" makes the bike a reliable machine...or maybe it's quite a few more "fixes"....you just never know. There's always some detractor no matter what type of bike you own...it's just more of a problem with something that's a bit older. The good news is that the vintage BMW you have is just about infinitely repairable, given the time, resources, and skills. You can't say that about many things these days. Sure rotors fail, but there's usually some signs but you can still go down the road a while with it that way. I've heard about people buying car batteries and strapping them to the back seat, turning off every unnecessary electrical device (mainly the headlight) and run for miles...they get home. People who are a little worried about that carry a spare rotor if they're taking a long trip. I carry spare spark plugs and have the parts to convert back to a points ignition system if my electronic system fails. It happened to me once, so now I'm prepared.

It's a tough call on these old girls... There's a series of posts on the vintage board about someone who's looking to buy a rolling basket case R69S. The real dilemma is does he try and get the "bucket o' parts" for cheap and then spend big bucks fixing it up to be a runner? Or does he find a different bike that's already a runner but needs some basic attention. Either way, you probably spend something close to the same amount but with one you wrench THEN ride while on the other you can ride now and wrench as you go. Not your case, I know, but there's going to be money involved. If you buy a newer model, well, there's the money you would have spent fixing the other up...maybe more.

These bikes are more of a passion and do require some attention. Just because it's a BMW doesn't mean it'll run forever or never needs any TLC. As you grow with it, you get more confident that when things do go wrong, you know where to turn to decide how much you can fix and how much you can't.

It's clear that in a bigger town or with other Airheads located closer, you'd have a better support group. But we're out here and can help...to a degree. No doubt, there's a learning curve here...sometimes the bike makes it steeper than it needs to be.

Kurt in S.A.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

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Darryl.Richman
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possible rear engine seal leaking oil

Post by Darryl.Richman »

I'm pretty mechanically inclined but I only have some of the tools. I have
found a guy who has been recommended over in Lubbock, Tx and he
said I could watch and ask questions while he works and possibly even
assist. This would be great for me but I still have to take my bike approximately 400 miles to do so. This person was at the ride in at
Deming a few months ago so you might know him Darryl but I'm not
sure. He seems to have a lot of experience working on the old airheads
and he owns a newer oilhead.

I don't recall this fellow, but I sent an email off to Don, and this is his reply: "One of the previous owners of High Plains BMW in Lubbock is extremely knowledgable about airheads. His name is Jim." It sounds like you've already hooked up with him. Don is the former owner of Deming Cycle Center, which used to be a BMW dealership (under Don's stewardship), and I would trust his opinion of the mechanic.
--Darryl Richman

khill
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bmw mechanics

Post by khill »

Hi Darryl,

I think I talked to him in the past and his name is Jim Davison if I remember correctly the guy I'm now talking about is Johnny Williams
and I think that Jim (who used to own the dealership) told me about him.
Jim will do some light work but not real involved stuff as he is making more off his new line of work. After I was told a price of $500 to put in
a new rear engine seal and including the oil pump O ring I decided to call
the BMW dealer in Bentonville, Arkansas and get a price for the same work. They were about $300 less than the dealer in Santa Fe. I know the
hourly rate is less back there but not all that much less. Maybe New Mexico is high because of little or no competition. I wish I trusted the old
R65 to ride back there to Arkansas and maybe it would make it just fine.

bombard4101
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possible rear engine seal leaking oil

Post by bombard4101 »

Just for grins, you may want to take a look at this article:
http://w6rec.com/duane/bmw/trans/index.htm

I know it's for an older bike, but the theory is the same.
If this is your problem, and the tranny front seal leaking, it's an easy job. As long as you consider pulling most of the rear of the bike apart easy. You can do it in a day.

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