replacing 350 oil pan gasket with engine still installed

[zacharywest34]

I have a 1971 c20 with a 350 and the oil pan gasket is leaking pretty bad, ive read a couple other posts and they say you can change the gasket without removing the engine which is what im trying to do. Does anyone have any tips or suggestions with this, anything would help, thanks.

[Jurassic-1]

On a 2 wheel drive it is much easier due to more room at rear of engine. You will need to remove motor mount bolts and unbolt your fan shroud to allow engine to clear fan. . Jack up engine in front. Place a block of wood under the balancer and lift up. If you have an engine hoist you can use it. The engine needs to be high enough to clear the oil pump pickup it will need to be lifted about 6 inches or so. Clean the pan and install a new gasket. I recommend changing the rear main seal if you are already in the bottom end. I have a Felpro 1 piece pan gasket on my 70 C10. I think it is worth the extra few dollars.

[slikside]

Originally Posted by Jurassic-1

On a 2 wheel drive it is much easier due to more room at rear of engine. You will need to remove motor mount bolts and unbolt your fan shroud to allow engine to clear fan. . Jack up engine in front. Place a block of wood under the balancer and lift up. If you have an engine hoist you can use it. The engine needs to be high enough to clear the oil pump pickup it will need to be lifted about 6 inches or so. Clean the pan and install a new gasket. I recommend changing the rear main seal if you are already in the bottom end. I have a Felpro 1 piece pan gasket on my 70 C10. I think it is worth the extra few dollars.

I have never performed the pan gasket replacement, but I did do a motor mount once, a loooong time ago. Not being critical, but if you're going to raise the engine that much, shouldn't you also loosen up or remove the 2 transmission mounting bolts to the crossmember? Seems like a lot less stress on the engine-transmission assembly that way.

[tcrist]

You can brace it by the balancer if you are very careful but it is better to brace it between the motor mount and the mount bracket. Just be sure that you have enough room between the block and the motor to remove the pan. Although sometimes you have to remove the motor mount to remove the pan. Just depends on the mount design.

Note that it is better to use something other than a 2X4. I have had them crush if they are not new.

Oh yea, don't forget that it is best to remove the cap and maybe even the rotor from the distributor so you do not damage them.

[zacharywest34]

Ok thank you I plan on doing it tomorrow we'll see how it goes

[Money_pit]

X2 on the fel pro 1 piece. They give you these little plastic studs to hold it all up while you get your bolts started

[70STOVEBOLT]

DO NOT prop the engine up under the damper! You may regret it.
X2 on the rear seal, unless it is completely dry. If any wetness at all replace it. Oil leaks do not go away on their own.

[Mmorgan32]

So you definitely have to jack the engine up? I pulled my engine not long ago and like a dumbass didn't replace the rear main on now it leaks like a mother

[trac209]

Originally Posted by Mmorgan32

So you definitely have to jack the engine up? I pulled my engine not long ago and like a dumbass didn't replace the rear main on now it leaks like a mother

I've done it without jacking engine but crank has to be in proper spot to get pan off

[Mmorgan32]

Putting the mount bolts back were a *****. Not fun at all I struggled with it for over an hour each side

[69pickupnyc]

OIL pan gasket replacement 69 pickup sbc. Can I remove the bolts from the engine mount , then jack up the engine by using a gas station jack with a piece of wood under the oil pan? I will also loosen the the transmission cross member bolts. Once the engine is jacked up put a piece of 2x4 between the engine mounts and the engine . Lower the engine Jack and then pull the oil pan out and replace the seal. I will also watch that I don't crush/crack the distributor when pushing up the engine.

[Steeveedee]

This thread is so old that the OP's pan gasket is probably leaking again, if he even still has the truck. As a first try, clean all around the pan/block interface and schmear #2 Permatex on it and let it cure. If you don't have serious blow-by, that should do the trick. If the crankshaft seals are leaking, this ain't gonna help. It won't be pretty, though.

[CCCC]

Not going to fly in the face of all of the engine-raise advice here, but am feeling rather certain that, with my 72 C20 Longhorn 2wd, I removed the pan, worked on the lower end and resealed everything without raising the engine. It is a BB 402. Is the engine lift necessary for only SBs?

[vics stuff]

You will need to unhook the exhaust pipe at the first connection and drive shaft.
I would also consider replacing the oil pump while in there. Just did mine a couple of years ago.
Vic

[toolboxchev]

That is always a pain, no offense just pull the motor, putting in a rear main seal upside down, 2 piece your looking at a 50/50 shot to get it right the first time.

The one piece pan gasket you may more success with. I hate doing work like that.

[BigBird05]

It takes like 20 min to pull a small block chevy. Pull the engine and do all of the gaskets and seals. Do it right the first time and you won't have to do it over.

[Steeveedee]

Originally Posted by BigBird05

It takes like 20 min to pull a small block chevy. Pull the engine and do all of the gaskets and seals. Do it right the first time and you won't have to do it over.

With a Sawzall and a torch, maybe. Please enlighten us all on how you got that engine out in 20 minutes. My record is 45 minutes, but I didn't use a torch or a Sawzall. It was a '64 Impala with manual steering and brakes, and a Muncie 4-speed. I pulled the front hood hinge bolts and rotated the hood back onto the windshield with a towel as padding, so that I didn't have to remove the hood.

[BigBird05]

When you work flat rate at a chevy dealer you learn to work fast.

[Happy_dan]

But most of us don't work at a Chevy dealer at flat rate. So it's more than 20 minutes for most of u.

I plan on pulling mine this winter. I am fortunate to have a heated shop and lift, but not the know how (yet). I'll figure it out.

[CCCC]

Is there a standard thread on the Forum or an FAQ item on this topic - maybe with some photos? I'd like to know more about the stated necessity to undo mounts and raise the engine in order to drop the pan of a small block in a C20 - before I start the task. Thanks for any help.