350 rear main

[pat]

Has anyone here changed out a leaky rear main with the engine still in the truck? Mine is leaking and I'm about to tackle that job. Was just looking for any info to make the job easier. Truck has a 350 and 700r4

 

[firebane]

1 piece will not be easy.
2 piece is easy peasy.

 

[MadOgre]

84 will be a 2 piece unless the motor has been swapped to a late 85/86 block.

I have done it. Its fairly straight forward in a k truck, with the c im thinking you have to lift the engine out of the mounts to drop the oil pan if I remember correctly.

Once you have the oil pan and transmission inspection cover off you remove the rear main bearing cap and oil pump pull out the old seal with out nicking any thing and replace with the new one and reinstall the main cap, Oil pump, reinstall the oil pan(I like the felpro blue rubber one piece perma gasket), reinstall the inspection cover and reinstall engine mount bolts.

There is a little more to it then that but that gives you a ball park idea of what your in for.

Double check that the oil sender is not leaking before starting as I have seen guys think their rear seal was leaking only to find out later that it was actually the oil sending unit that was leaking

 

[rich weyand]

... Double check that the oil sender is not leaking before starting as I have seen guys think their rear seal was leaking only to find out later that it was actually the oil sending unit that was leaking

Yeah, or the power steering pump. P/S fluid just has to show up on the bottom of the dipstick. Overfill it and you can be pushing it out the filler past the gasket.

 

[pat]

Cool. I wasn't sure if anything was in the way of getting the pan out or not. No biggie. It's not the oil sender.

 

[pat]

The engine is a gmpp crate motor. It's a later model 350.

 

[MadOgre]

Oh well its probably a one piece rear seal in which case the tranny has to come out! Sorry

 

[MadOgre]

Definitely make sure which one it is before starting anything.

 

[MadOgre]

The engine is a gmpp crate motor. It's a later model 350.

does it have 4 bolts in the center of the valve covers? if so its a one piece

 

[pat]

Well damn. it does have 4 bolts in the valve covers. Well, looks like I'll have to pull the trans out.

 

[pat]

Anyone know the part number for the one piece seal?

 

[MadOgre]

You have to pull the flex plate off to get at the seal. starter comes off too obviously

 

[pat]

Yea I know. I've done them before. Just never with the engine in the truck. Ive been trying to find the seal for it online. I need a part number to take up to the parts store. Seeing as I can't just tell them the make and model to get it. The guys that work there are usually to incompetent enough to be much help.

 

[MadOgre]

I guess you don't have any info for the engine ? Gm should be able to tell you what you need seeing as it is a crate motor.

 

[pat]

I ended up getting everything I needed. I'm working on it now. Not to bad. Just took it to the auto shop on base. They have lifts I've been busting my ass on this truck. so working on it in a professional shop is like being spoiled.