Engine oil inside Trans underpan
Thread Starter
Instructor
Joined: Nov 2011
Posts: 212
Likes: 18
From: Bucks County, PA
Engine oil inside Trans underpan
Hi all,
I was replacing my starter on my 1980 auto transmission car do day and was looking at the many leaks while I had it up in the air. The starter was covered in greasy grime! There is usually a drip of oil hanging out on the drain plug and the underpan just behind it. As a a newbie to these cars & engines I did not realize that there was actually a hole in the bottom of the underpan. I wiped away the hanging drip of oil from the underpan and quite a bit came out of what I found out was the hole. I had thought that the oil was coming from an old oil pan gasket or the drain plug. Now with oil INSIDE the bell housing/underpan I would think that I need to replace my rear main seal as well? Am I correct in my thinking? I may as well replace both RMS a oil pan gasket while I'm at it.
This will be priority #3 after stoping my power steering and brake caliper fountains. I would just like this thing to stop spewing fluids in my garage!!
I was replacing my starter on my 1980 auto transmission car do day and was looking at the many leaks while I had it up in the air. The starter was covered in greasy grime! There is usually a drip of oil hanging out on the drain plug and the underpan just behind it. As a a newbie to these cars & engines I did not realize that there was actually a hole in the bottom of the underpan. I wiped away the hanging drip of oil from the underpan and quite a bit came out of what I found out was the hole. I had thought that the oil was coming from an old oil pan gasket or the drain plug. Now with oil INSIDE the bell housing/underpan I would think that I need to replace my rear main seal as well? Am I correct in my thinking? I may as well replace both RMS a oil pan gasket while I'm at it.
This will be priority #3 after stoping my power steering and brake caliper fountains. I would just like this thing to stop spewing fluids in my garage!!
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
The underpan you are refering to is merely a dustcover / stone guard for the torque convertor with a weep hole. The question is, what color are the drops coming out? If redish then its likely the front seal on the tranny pump. If its brownish oil, then its likely the rear main seal on the block. Four small bolts and that cover drops down for a closer inspection.
Not too bad a job replacing rear main seal. Many suggestions on this forum. Of course the pan, oil pump and main bearing will have to come out. To drop the pan the idler arms two bolts will have to be removed so the steering linkage drops down for pan clearance. When you install a new rear seal, always "clock it" so the seal gaps are at 8 o clock & 2 o clock instead of lining up with the pan gap (3 oclock & 9 oclock).
A oil soaked starter is likely from the valvecover gaskets, simple fix.
Not too bad a job replacing rear main seal. Many suggestions on this forum. Of course the pan, oil pump and main bearing will have to come out. To drop the pan the idler arms two bolts will have to be removed so the steering linkage drops down for pan clearance. When you install a new rear seal, always "clock it" so the seal gaps are at 8 o clock & 2 o clock instead of lining up with the pan gap (3 oclock & 9 oclock).
A oil soaked starter is likely from the valvecover gaskets, simple fix.
Thread Starter
Instructor
Joined: Nov 2011
Posts: 212
Likes: 18
From: Bucks County, PA
I actually had the valve cover gaskets replaced a little while ago While it was in the shop, so you are spot on!
Le Mans Master
Joined: Mar 2004
Posts: 7,511
Likes: 1,519
From: Little Rock AR
Oil leaking from anywhere will make you think it is the rear main seal or oil pan. Degrease the engine well and hit it with talcum powder then drive for a few miles to see exactly where the oil is actually leaking from. Might save you some work.
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