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Now that I have replaced the rear main seal, oil pump cover and cover o-ring, it’s time to clean up the leaking pan gasket. I have the engine out of the frame, so I’m just going to tip it on it’s side to get at the pan and bolts holding it to the engine block.
Engine on Side to Remove Dirty Oil Pan
Removing the Oil Pan
There are 14 10mm bolts. I loosened them in a cross-wise pattern and was careful that the pan didn’t fall to the ground and ding the edge of the pan. This exposes the inside of the engine.
Oil Pan Removed Showing Inside of Engine
The large screen is attached to the oil pickup that goes to the oil pump. Just behind it you can see the camshaft which connects to the oil pump on one the left end and to the points on the right end.
Cleaning the Pan, Loosening the Pan Gasket
Now, time to clean the grunge off everything and to remove the old pan gasket. I took the pan to the parts washer and started removing the crusty layers of crud.
Cleaning Grunge Off Oil Pan in Parts Washer
When I removed the pan, the gasket stayed in one piece and was attached to the top of the pan. I applied a liberal amount of Permatex Gasket Remover to the gasket and let it soak in. In about 30 minutes, I added a second application after it had partially soaked in and let it sit for another 30 minutes.
Permatex Gasket Remover Soaking In
In the meantime, I removed the oil pickup screen to clean it. I carefully pulled up on the wire retaining bail with pliers so I didn’t bend it and removed the screen. Then I scrubbed the screen in the parts washer and soaked the pan bolts in ChemTool B12 Carburetor cleaner. THIS IS NASTY STUFF. I use gloves whenever I handle it.
Oil Pickup Screen & Pan Bolts in Carb Cleaner
Check Torque on Oil Pickup Bolts
As the pan bolts soaked, I took my INCH/Pound torque wrench and checked that the bolts holding the oil pickup were not loose. After all these years, its a good idea to be sure those bolts are snug and haven’t gotten loose. I set the torque to 72 INCH/pounds and got one to snug just a bit.
Checking Torque (72 INCH/pounds) on Oil Pickup Bolts
Remove Pan Gasket
After an hour of letting the Permatex soak into the pan gasket, I took a 1 inch wide paint scraper and checked to see if I could get it between the gasket and the edge of the oil pan. It slipped in pretty easy and I carefully pushed it around the edge of the pan to get the old gasket off.
Permatex Gasket Remover & Putty Knife Easily Remove Old Gasket
Installing New Pan Gasket
There is still some old glue and gasket on the edge. I added more gasket remover and let it sit for 15 minutes and then carefully scrapped along the edge of the pan with very little pressure to clean the glue and gasket off the pan. I followed this up with “000” steel wool. Then I cleaned it all up with brake cleaner so it shined.
Clean & Polished Pan Mating Surface
I did the same thing to the edge of the engine block so the edge was clean and shiny. I also checked the edges of the pan and the block for any nicks or high spots and found none. Then I put the screen and wire bale back on.
Clean Engine Mating Surface on Engine Block
I removed the bolts from the carburetor cleaner and lightly buffed the threads with my fine wire wheel to be sure they were clean. Time to put the gasket on the pan. It goes one way with the lettering facing you.
New Pan Gasket-Printing Facing You
Torquing Pan Bolts
Then starting in the middle of the pan I threaded bolts in a cross-wise pattern. At each stage of bolt tightening, I continue to do it in the same cross-wise pattern. I finger tightened them so they were all snug and the pan was centered on the gasket. Then, I set the torque wrench to only 20 INCH/Pounds and gently tightened the bolts. Then I increased to 40 INCH/Pounds and finished up at 70 INCH/Pounds. Here is the final product.
Clean Oil Pan with New Pan Gasket
Not quite polished enough to shave in, but nice and clean.
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Brook,
I am trying to remove the oil pan from the engine. It is stuck pretty good and will not release. I hesitate to use a putty knife to pry it loose since I don’t want to damage either surface. Could used some advice here. Thanks.
Dan
Hi Dan,
I would try a rubber mallet and see if that will budge the pan off the gasket. You can use a small wood block against the edge of the pan to protect the fins. I think a couple hits should shear the pan from the gasket or gasket from the engine.
Best.
Brook.
Brook,
Thank you for the quick reply. Your site is extremely helpful.
Dan
I can’t get the oil pan off. I’ve heated it, tried a guitar string and nothing is working. It looks like there’s some permatex oozing out of the sides….any suggestions are greatly appreciated!
Hi Longhorn89,
Bummer. Another technique that may work is to very CAREFULLY use a paint scraper blade. You DO NOT want to scratch the pan edge or the engine block edge where the stuck gasket attaches to. Try to split the gasket from the pan surface by holding the blade parallel to the sealing edge of the pan using a gentle tap with a hammer to get the blade to go between the metal pan surface and the gasket. If you get the blade inserted, you can usually pull it along the pan edge to continue to separate the gasket from the pan.
Another idea is to use Permatex Gasket remover,
http://www.permatex.com/products-2/product-categories/gasketing/gasket-removers/permatex-gasket-remover-low-voc-formula-detail
available at most auto parts stores. Apply it the edge of the gasket and let it soak in. Apply more and let it soak in. Apply more and let it soak in. Then use a plastic or rubber hammer and tap the pan along the edge to help shear it off the gasket.
I hope these ideas help.
Best.
Brook.
I finally got it off by heating it up a little and using the 2×4 and mallet method…It took a couple hits harder than I like to hit a 44yr old bike, but she popped right off. Thanks for the helpful site!
Longhorn89,
It’s a good feeling when you finally get a stubborn part apart without smashing your thumb, cutting your knuckle or breaking an adjacent part that costs 10x more than the part you were working on. 🙂
I’m glad the site has been helpful.
Best.
Brook.
Hi Brook,
I just replaced my oil pan gasket this past saturday. Noticed sunday that it was weeping slightly so I wiped off the weepage around the gakset and checked again this morning before riding to work. Looks like it is still weeping oil.
Have you noticed this happen? I was working with a beam style in-lb torque wrench and some of the bolts seemed like they might be partially stripped already. When I removed the bolts they had some non-permanent liquid gasket applied to them it seems.
Wondering if it would be a bad idea to try to check torque on them again (in cross pattern).
Hi Jonathan,
Due to the low torque values for those bolts, I used an INCH/pound wrench not FOOT/pound. I’ve been told that if the torque setting you need is the lower 10% of the range of a wrench, the accuracy and repeatability are not very good and you can end up with over torqued bolts and stripped threads. Also, I’ve read that beam style torque wrenches tend to be less accurate than the clutch style which “click” when you reach the torque setting. This maybe more of an issue with lower torque settings as a bit more grunt on the wrench can cause a large increase in the torque applied.
If you have some stripped threads, then I think helicoil inserts are the proper way to repair them. From what I have read, over tightening the pan bolts happens all too frequently.
I hope this is helpful.
Best.
Brook.
Is it a big fix to repair 75/7swb speedometer. Dial flew off and is under glass. Tach runs ok. Looks like speedo drive is all over the place. Any suggestions would b of help Don/Canada
Hi Don,
Thanks for visiting.
In the back of my mind, I’ve seen a blog on fixing the speedometer needle, but I didn’t save the link. Perhaps some google searching will surface it for you.
My suggestion is to post your question to the airheads forum.
-> [email protected]
It’s a very informed group of enthusiasts and professionals with a deep love of BMW airhead bikes.
I have done business with Palo Alto Speedometer for repairs.
-> http://www.paspeedo.com
They are very knowledgeable about BMW speedometers.
I hope this helps.
Best.
Brook.
Dan,
I have found the very detailed documentation of your work invaluable to my winter teardown and rebuild of my 1988 R100RT. I specifically enjoy the numerous photos and insight into your technique.
A Very Big Thank You for your efforts!
As well as your responses to others in need…THANKS! (in advance)…
Buttering up complete; regarding the oil pan gasket — I didn’t see you use any hylomar/gasket goo on the pan. Is that correct? Did I miss something? I read in the clymer manual to use a gasket sealer. Any thoughts you might have or advice would be greatly appreciated!
Thanks again.
Best,
Stew in Guelph, ON Canada
Hi Stew,
No worries about the confusion on my first name, brake cleaner can do that 🙂
I’m glad this material has helped you over the winter on your project. I’m about ready to start posting on my 1983 R100RS build project, but your 1988 is even newer than this, so there will still be things that differ between the bikes.
The pan goes on dry IIRC. The newer, non-cork versions, have a heat activated glue on the side with the writing on it to help seal the gasket. It is important to have cleaned the pan and engine case so there are no bits of glue, sealer or gasket. I use brake cleaner on the surfaces and blow some inside the holes to make sure everything is nice and clean without any oil.
For a good overview and many details on pan gaskets, see Bob Fleischer’s write-up:
http://bmwmotorcycletech.info/pangasket.htm
I hope this helps Stew.
Best.
Brook.
Brook,
It does help. Every little bit of information you make note of in your writing allows a (47 year old) rookie to have the confidence to complete the task himself.
Thank you for the advice. I look forward to reading your endeavours on the RS. Enjoy your spring!
STEW
Brook,
In your experience and travels, would you say that having an oil pan with a .080 warp requires machining or replacement? Or would the gasket and bolts take up the warp and get a good seal?
the warp is cross corner front to back not side to side. I’m planning to poll the ADVrider inmates, but I also thought to check with you as a educated resource. Many thanks and kind regards,
STEW in Guelph ON
Hi Stew,
Hmmm … I can’t say if this is too much warp or not. I’d advise you to post a note to the micapeak airheads forum as it is frequented by long time airhead mechanics and A-grade owners. I’ve not found ADVrider advice correct on multiple occasions, but YMMV.
http://micapeak.com/mailman/listinfo/AIRHEADS
If you had oil leaks from the pan, and none of the bolts were stripped, then that suggests there maybe too much warp. Again, I can’t vouch that 8-hundreths is too much for the gasket to compensate for.
I hope this helps.
Best.
Brook.
Brook,
As Always, a voice of reason and experience!
Many thanks, I’ll check into Micapeek Forums.
Thank you very much. Happy Wrenching!
STEW in Guelph
Brook – As you indicate, Fleischer has a lot to say about pans and mentions honing a pan with sand paper on a glass plate using a figure 8 motion.
Also, I cant figure out exactly what a “cross-wise pattern” looks like. Would that be starting in the center and moving to the ends? So as to avoid gasket wrinkles?
I am now trying to figure out how to pronounce Guelph!
Hi Michael,
The figure-8 motion helps equalize the removal of material across the edge of the pan so the edges stay flat and don’t get rounded.
Please be sure you use an INCH-POUND torque wrench as the torque value is very low on these bolts and they strip very easily.
A cross-wise pattern of tightening the bolts starts in the middle of the pan. Torque the center bolt on one side, then torque the opposing bolt on the other side. Return to the first side and move forward one bolt and torque it. On the other side torque the opposing bolt. Return to the first side and move one bolt to the rear of the center bolt and torque it. Repeat this pattern of one more bolt forward then one more bolt to the rear until all bolts are torqued. Then, go around to check each one again to ensure they are all at the same torque.
Yes, the idea is to snug the gasket without deforming it.
After riding the bike a 100 miles or so, go back and check the torque on all the bolts and tighten any bolts that have loosened due to gasket compression. I don’t bother to do this in a cross-wise pattern, but no harm if you do so.
I hope this helps.
Best.
Brook.