View Full Version : Volvo MD11C oil leak

Jim Chorey
09-02-2008, 11:43 PM
"I'm suspicious that my 1976 MD-11C with approx 2700 hours has developed a rear main seal oil leak. There are oil drips under the engine in the drip pan at the rear and it is not the clean oil in the MS reverse gear. I can "almost easily" get to the rear of the engine and am tempted to consider replacing this rear main seal if this checks out to be the problem. I'm pretty sure I can pull the MS reverse gear easily enough and should have enough working room. Would anyone offer any advice about if it is reasonable to consider replacing this seal without pulling the engine? Any suggestions. Other than the oil leak, this has been a very reliable engine. Thanks in advance for your time and thoughts."

09-03-2008, 09:17 AM
11C does not have a rear seal. Only gasket on rear gear case. Check gasket where MS bolts up or leaking above and running down case.

09-08-2008, 07:40 AM
"I am interested as to where you find the oil leak. I have a similar leak on my MD11C. I intend to tackle it this winter. I think I can get to the timing cover without removing the engine. I also have a piece broken off the Timing Cover casting at the port lower motor mount tapped hole. I have to decide whether there is enough left to use a stud, to repair it or find a used one. If anybody has one laying around we could work a deal.
On another subject. Has anybody looked at filtering the crankcase vent? I have an annoying drip from the aft air cleaner/can which gets a lot worse at high rpm in rough weather. I was considering air sep or Racor CCV820"

11-17-2008, 01:27 PM
"Thanks DickV for that golden piece of information re no rear main seal. (How does the oil get retained in the crank case?)
I have two MD11Cs on the bench, one destined for installation, which according to the previous owner, may have an oil leak of the type suspected by Jim Chorey. However, I see problems with the timing cover gasket (a home-made cork one) and the valve cover gaskets, both of which could be dribbling oil downwards. Tearing the engine rear area apart to get at the "seal" or bell housing joints is a major, major ugly proposition, (and Graham, it wouldn't even be possible to do in-situ) so I'm likely going to just replace the aforementioned gaskets and hope for the best. Graham, I may be scrapping/parting out my old engine, which has a chewed up crankshaft pin, so I may be able to mail you a timing cover.

11-19-2008, 10:20 AM
Yeah when the mechanic went to pull my trannsmission for repair low and behold oil poured out everywhere. He didn't know either about the lack of an oil seal aft. Then they charged me t & m to clean up the oil. f__ks