[slammed 57]

i havea 383 wit a rear main seal leak , i replaced it and itstill leaks, someone said i should have applied some grease on the inner seal where the crank sits, is this true and could this be the reason its still leaking since did not pre grese it. any help would be appriciated

[oldbogie]

Originally Posted by slammed 57

i havea 383 wit a rear main seal leak , i replaced it and itstill leaks, someone said i should have applied some grease on the inner seal where the crank sits, is this true and could this be the reason its still leaking since did not pre grese it. any help would be appriciated

One or two piece seal?

Bogie

[cobalt327]

Originally Posted by slammed 57

i havea 383 wit a rear main seal leak , i replaced it and itstill leaks, someone said i should have applied some grease on the inner seal where the crank sits, is this true and could this be the reason its still leaking since did not pre grese it. any help would be appriciated

The reason the seal is lubed prior to starting the engine, is so there's enough lubrication to keep the seal from getting hot from friction before there's oil thrown onto by the running engine. If the seal gets too hot, it will deform the sealing lip or out right wear it down to the point that it no longer is able to do its job.

Oil can also go past the joint of a 2-piece seal. Judicious use of RTV usually is sufficient to prevent this, though. The rear main cap also needs a dab of sealer on both sides.

HERE is the procedure for a 2-piece seal.

[slammed 57]

its a two peice seal and i did use rtv sealant, but no lube . do you think i should look at another posibility why its leaking, the motor only has 500 miles on it since completly rebuild. this is driving me nuts

[roadhogg]

i had the same trouble so put a one piece gasket by mr.gasket and that stop it.the front and rear seal oil pan gasket or all one piece

[S10 Racer]

You need to check the crank at the seal also. If it's the original crank, there may be a groove worn in it where the seal "rides" on it. This also happens on the harmonic balancer where the front seal "rides". You may not think that rubber could wear into cast but it does. You may also have a crankcase ventilation problem and pressure in the crankcase is forcing oil past the seal.

[staleg]

Remember to twist the seal a little so it not ends up with the seal joints on the same two places as where the rear main cap connects to the block.