71 R50/5 stuck oil pan

[jdvorchak]

I was trying drop the oil pan on the R50 and noticed that one of the bolts, front left, was missing. Also right rear bolt stripped. Now to the real problem. No matter what I've tried I can't get the pan off the bike. Of course I've removed all 14 of the bolts and drained the old oil. I tried hitting the sides of the oil pan with a rubber dead blow hammer. I've tried a couple of times soaking the gasket area with PB Blaster, let it sit and hour and start hitting the pan again. Downward blows with the rubber dead blow. Before I do something stupid like try to force a screwdriver tip between the crank case and the pan I thought I'd ask. After about 2 hours of trying to get the pan off I decided to put the bolts back in, fill with oil and new filter and try my test run and first startup in about 20 to 30 years. I'm hoping that a few heat cool cycles will help loosen it but I'm don't have much confidence in that tact. Eventually I have to get the pan off to repair the stripped bolt and see if the left front is just missing or broken off flush with the crank case surface. I don't know why I didn't just try to install one of the removed bolts into the missing bolt hole...senior moment....

I had thought about using a propane torch to heat the pan but having an open flame near a motorcycle engine just doesn't settle well with me. But I suppose if I de-grease the lower engine parts it would be ok.

any tricks?

[George Ryals]

It sounds like some misinformed person used something like "yellow death" (on both sides of the gasket) weather stripping cement to ensure a no leak seal. A sharp edged 1" wide putty knife should be able to split the gasket and get the pan off.

[jdvorchak]

Ok thanks.. I'll sharpen a putty knife and give it a try. At least I have wire brushes and the case bottom is easy to get to for final surface clean. I'm pretty sure those gaskets go on dry. Correct me if I'm wrong.

[jagarra]

Could you use a wooden dowel through the dip stick hole and nudge it from there?

[CVA-42]

When you get the pan off and get it all sorted out, I would replace all of those old bolts with new ones. When you re-install the pan, be very careful when tightening the bolts as the bolt holes in the bottom of the engine are very, very easy to strip out. Don't use a torque wrench or a micro-torque wrench of any kind. Just feel them in with a small ratchet or wrench...

[Bamboo812]

...and put some kind of sealant on the bolt that goes all the way through the case (it's one of the ones near the oil filter cover).

[ME 109]

The trick to getting it off is to heat just the front of the pan with a heat gun and then give it a whack with a hammer and block of wood.
I was skeptical re heating just the front, but this has been a successful method to a few stuck sump inquiries over on ADV.

[jdvorchak]

All good suggestions. I was using my heat gun on the side of the pan. I'll try the front. Also thanks for the tip on the bolt that goes all the way trough. I thought that was funny that oil dripped out of that bolt when I removed it.

[Duane Ausherman]

Someone must have glued it on. They come off easily otherwise. I like the putty knife insertion, as that probably won't mark the case.

Once off, you will find the pan surface distorted at each bolt hole. Use a hammer to flatten it out again. As mentioned, use great care in tightening those bolts. I ONLY use a screwdriver with a socket to tighten and even then not very tight.

Make sure that each hole that goes through is totally clean and use some sealant on the bolts so that oil doesn't creep down the threads and out the bottom.

After a couple of hundred miles, go around and check the torque of each bolt.

Those bolts are not known to fall out.

[jdvorchak]

Thank you Duane. I figured someone had glued it on to try to compensate for the stripped bolt, right rear. Once I get the pan off I have to address the missing bolt, front left (hope it's not broken off) and that stripped bolt. I'm thinking I can use a timecert rather than drill and tap for a larger bolt.

Oh and I am aware of the torque on those bolts and I used my 1/4 inch drive screwdriver handle and socket to snug them up. I can source those bolts from the local BMW dealer and will ask them what they suggest for repairing the stripped bolt. I'm sure they've seen that a lot. Every time I go in there for parts the nice parts lady asks if I want to talk to a mechanic for any needed advice. Gateway BMW in St. Louis, MO is a great place to do business. Besides it is a nice easy 30 minute ride from here and the weather has been perfect for riding lately.