'37-4D
Well Known Member
I'm in Canada. Some one said I can still find it on our shelves here, however it's not advertised!?
Rear main seal leak??
- Thread starter RCE1962
- Start date
'37-4D
Well Known Member
I have been building these engines for twenty five years or more and have never had one that didn’t develop a leak at the rear main seal. I know I’m doing everything correct. Even with the stroker crank I have oil dripping occasionally out of the dust cover hole. I don’t pay any attention to it anymore. Hell a little snot doesn’t hurt anything. That’s what the hole in the dust cover is for.
Mine leaves a mark, kinda like an old Harley.
chuckl
Well Known Member
I have a 56 Chevy with a warmed up 61 348, with a similar rear seal leak down through dust cover. No oil coming through the draft tube nor is oil/vapor/pressure coming through the oil filler tube. Most of the oil comes out after the engine is shut down, while some drips while running. I am running Rotella 15W-40, with Shell Zinc additive.
I can remove the oil pan easily. I have photo and video evidence of installing (correctly) the rear seal and the small rubber tabs under the rear main cap. Can these items be replaced with the engine in the car, by taking the rear cap off (possibly one more cap), removing the tabs and rotating the two halves of the rear seal out of their grooves. It will be a major PIA to remove the engine, as I have power steering, A/C, power disc brakes, custom shroud, etc.--all is CLOSE proximity. Any recommendations for sealer under the caps?
I can remove the oil pan easily. I have photo and video evidence of installing (correctly) the rear seal and the small rubber tabs under the rear main cap. Can these items be replaced with the engine in the car, by taking the rear cap off (possibly one more cap), removing the tabs and rotating the two halves of the rear seal out of their grooves. It will be a major PIA to remove the engine, as I have power steering, A/C, power disc brakes, custom shroud, etc.--all is CLOSE proximity. Any recommendations for sealer under the caps?
Yes you can replace the seal by removing the rear main cap.
I use the ultra black sealer. You should stagger the end gap on the seal so the parting line is not inline with the cap.
I use the ultra black sealer. You should stagger the end gap on the seal so the parting line is not inline with the cap.
chuckl
Well Known Member
Should the very ends of the seal lip mating surface receive any sealer/RTV? Both sides of the rubber tabs and under the cap itself?
I don't use any on the seal.
I do use a small amount on the tabs, I don't like to get any between the cap mating surface.
I do use a small amount on the tabs, I don't like to get any between the cap mating surface.
I do that.
A word on the oil seal conditioner additives, the way they work is to soften the rubber of the sealing lip to better conform,the down side is it also wears quicker so if the rig gets driven a lot the leak will return eventually and will require replacement.But for an occasionally driven car it would be a good way to avoid seal replacement for a long time,if it works.For a while the hot ticket on 1 piece rear main seals was the blue silicone rubber seal,but I haven't heard much about them for a while and I don't think I ever saw them in 2 piece seals,they didn't tend to harden up after a while like regular rubber seals.
Hey guys i have an oil leak on my 348 w. Its a fresh rebuild and not installed yet. I put an auxillary pump on it to pressure up the system and my rear cam plug is lking. Not terribly but is lking. Tried two cam plugs since and same problem. Once i tried permatex and again with rtv. I'm building 70-80 lbs on the aux pump. Am i expecting too good of a seal from the cam plug? I'm sure some rear seals have been changed expecting to fx a leak coming frm the cam plug. Thanks
It should hold oil pressure, did you inspect the bore to make sure it didn't have any gouges ?