1 piece vs 4 piece oil pank gaskets

[Erik the Awful]

Good points, BOOT, on cleanliness and pan straightness.

I, too like the pea-sized dabs of silicone in the corners, but I put absolutely nothing on the pan side of the one-piece gasket.

 

[Pinger]

I have a vague memory of regret for not removing the starter motor and dipstick tube.....

 

[Erik the Awful]

I have a vague memory of regret for not removing the starter motor and dipstick tube.....

Pull the dipstick halfway out before reinstallation. I believe I left my starter in place. My biggest issue was that the pan moves in and out easy without pulling the bolts out of the motor mounts. The aftermarket replacement pan, that looked identical, wouldn't pass the crossmember. I had to raise the motor.

 

[Pinger]

Pull the dipstick halfway out before reinstallation. I believe I left my starter in place. My biggest issue was that the pan moves in and out easy without pulling the bolts out of the motor mounts. The aftermarket replacement pan, that looked identical, wouldn't pass the crossmember. I had to raise the motor.

I pulled the dipstick out but was reluctant to remove the starter for some reason. It and some cooler lines IIRC caused me to have to tilt the pan sideways to clear them - which put it out of synch with the plastic mandrels I was using. Still, being able to remove and refit a pan without even having to use a jack isn't anything to complain about. I get the feeling that 4WD complicates things a bit though.

 

[HotWheelsBurban]

Pan warping is why they started using the steel rails on the outside of the pan flanges, they act like big washers to spread out the load. Very definitely needed on Chevy oil pan.

 

[Frank Enstein]

For 2 piece rear main blocks FEL-OS34510T is the part number I always recommend.

Clean the gasket surfaces squeaky clean. Like brake cleaner on white paper towel clean. If the paper towel isn't white after wiping the surface it's still dirty. Silicone will not stick to an oily surface (right stuff is more tolarent of this but it's still best practice).

I use Gasgasinch (EDL-9300) to hold the gasket to the block and pan. A bead of silicone in the 4 corners top and bottom as wide as the gasket
and fill in the dipstick hole on whatever side you aren't putting the dipstick on.

Don't let the silicone "skin over" but assemble immediately. Tighten the bolts finger tight only.

Go do something else for a while to let the silicone cure. After it cures tighten the bolts to spec.

This applies to one piece seals as well except for the dipstick part.

This basically glues the pan on and when you tighten the bolts you will put pressure on the seal.

It wont leak after that!

The part numbers above are at Summit Racing Equipment.

 

[Steve A]

No way would I ever use a 4 pc oil pan gasket again if I could help it. FEL-PRO OS34510T is a 1 pc replacement for the early models, just make sure all the bolt holes have the metal sleeves (torque limiters) in them. I would use the reinforcement rails on the pan (if possible) as well as making sure the pan rail holes weren't dimpled.
Oil Pan Rail Reinforcement 12553058 (LH) 12553059 (RH)