Rear Main Seal cross member
 

This is post is actually a continuation of a previous post but for some reason I cannot access my old post.

Anyway small block 350 on chevy c10, oil leak all the usual suspects are ok which bring to the two possible suspects.

1 rear oil pan seal
2 rear main seal

1st time I had a refutable garage replace rear oil pan ( three piece style, on the rear oil pan seal I used also RTV) and also replaced the rear main seal(rubber style)but when checking after driving oil is still on the dust cover and starter.

2nd time I did it myself but I used one piece oil pan gasket ( on the rear oil pan seal part I did not put any RTV) and rear main seal was Fluoroelastomer material. After checking same oil leak problem is still there.

After removing oil pump etc and looking at the rear main seal seemed nice and dry.

Now I have heard different opinions on what is best oil pan gasket thats why I tried both. Now my theory is there is a problem with the (see pic) bracket( between main bearing cap and oil pump) that connects to oil pump is pitted so where the rear oil pan gasket goes into the slot its leaking from there. Could those pits cause that problem?

Another thing can the oil pan be removed without pulling the engine? I ask this because I can get the oil pan down of course but not fully removed because it will not slide across the cross member. I would like to get it down so I can put the oil pan gasket on while its down and see how the oil pan gasket is setting in the pan and the oil pump bracket.

Re: Rear Main Seal cross member
 

I am no expert, just throwing it out there, but on the rear main seal are you pushing it 3/8" up into the slot so the seam isn't lined up with the cap? Can you get another one of those caps so it isn't pitted?

Re: Rear Main Seal cross member
 

yes I tired both the first time it was plush and the second installation of rear main seal I offset it 3/8". I don't think I can get another one I was thinking to take it to machine shop and have them smooth it out, but I was waiting on advice as to not waste time and money.

Re: Rear Main Seal cross member
 

Nothing wrong with that cap, likely your oil pan is slightly out of shape.
Lift the motor up about 4 inches in the front and rotate the crank enough to slide the pan out.
Put the pan on with no gasket after you get it all cleaned up.
Put a flashlight in the pan (turn it on!!) and look at the gap on the curved seal area. If it looks squished in one area you'll need to fix it. Not hard to see with the light inside.
Once you fix it put the pan back on with no sealer on the cap.

Re: Rear Main Seal cross member
 

Just a thought has happened to me, do not get mad but check back of valve cover gasket and also oil pressure sending unit on back top of block .. I only say this cause it can look like you have bad oil leak at pan.

Re: Rear Main Seal cross member
 

Maybe crazy question but novice here but can it be raised of course via hoist but without removing motor mounts, etc.....?

Re: Rear Main Seal cross member
 

Thanks and for sure not getting mad i checked those and I don't see any oil coming down from there, I mean I should see something flowing or dropping down but its dry from those two areas coming downwards.

Re: Rear Main Seal cross member
 

Just unbolt the motor mount from the tower. One bolt accessible from underneath. Lift the motor up and put a 2x4 in between the mount and tower. Watch for anything else that might hang up when you lift it. Like rad hoses or dizzy cap.