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Oil Leak Thru Rear Seal?

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J

Jimmy74

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On my newly rebuilt 1275 engine I have engine oil leaking out the drain hole in the transmission. TWO questions :

Where 'other' than the rear seal might this oile be coming from.

Can the rear seal be service with the engine in the car and the oil pan removed?

Thanks for your comments!
 
There are are two scroll seals "in" the bell housing, one on the rear of the engine and one on the front of the transmission. If the leak goes away when the nose of the car is up then it is the transmission, if the leak gets worse when the engine is running it is the scroll seal on the engine. Make sure the engine is vented properly since crankcase pressure will make the engine leak bad here. Did you disrupt the top of the scroll seal (three bolts on a half circle) when you rebuilt the engine and if so how did you reposition it back in place?
 
I'm not sure about the 1275, but on my 1500 there is a copper crush washer under the bottom bell housing bolt. I had a bad oil leak there due to someone putting a split ring lock washer there. May be the case in yours. Good luck
 
How about the oil pump cover?
 
Jimmy:
As Chris mentioned you need to make certain the engine is properly vented so back pressure doesn't build up and cause the oil to leak through the rear seal. There are threads on the formum that discuss various ways to make certain the engine is properly vented by use of a vented rocker arm cover and PCV valve. You will have to remove the engine transmission to correct placement of the rear scroll etc. so check out the venting first....and make certain the engine or tansmission aren't overfilled.
Good luck!
Roy :cheers:
 
During the rebuild I requested that the welsch plugs in the oil galleys be removed and replaced with grub screws. The end result was that two of the 4 were leaking after rebuild. The front passenger side and rear passenger side plugs were guilty. oil was running down the inside if the engine back plate and when it reached the cut out for the crank it traversed over the rear "eye brow" (top of scroll seal) and conveniently dropped into the bell housing. I am pleased to report that the cotter pin in the bottom of the tranny worked flawlessly and deposited copious amount of oil in my and my aqaintances driveways!

The machine shop did not bore the galley holes, they only tapped them. Has anyone had this done b4? Didja have a leak. Should I smack my machinist?

Thanks for your replies fellas.
 
Smack machinist, any compatant engine builder or machinest should know how to do that job.
 
I just noticed oil under my car when tieing it down on thr trailer last week. I need more vaccum on the engine as I could also smell a bit of blowby when I romp on the gas, so it must be blowing out the rear seal. The weber hose to the breather just is not getting it done. I need a hose into the intake like other motors have. I am going to make a spacer block to insulate and raise the carb a bit and also put a port into it to tie the vent hose to and get more vaccum to the crankcase and stop the rear main from leaking.
 
Is this the common method? Spacer with a port? My Opel had a port on the intake for this, going to the valve cover "metered" port, very tiny some vacuum, not too much.
 
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