Skynyrd

I think I have a rear main seal leaking which has gotten worse.
440 motor. Noticed the pressure going down to around 40 right back to 70 or 80 ,rev a little goes up back to idle & drops to 40,50 or so . It never lost pressure but not acting normal.
Can a rear seal leaking effect pressure like that? I,m thinking yes. Normal for this motor is 80 at startup then around 70 after it warms.

440 30 over ,race motor newly rebuilt . It has been steady until now and the leak has gotten
Worse..... thanks

Coronet 500

Rear seal no pressure, two plugs in photo have pump pressure.

https://moparforums.com/forums/f62/o...k-440-a-16627/

Skynyrd

Thanks , Coronet 500.
Good info. So there isn't pump pressure at the rear main...
Then it has to be something other than main....because of the oil pressure mechanical gage moving around . I will check this out....

moe7404

date 8-31-14. i just found 2 permatex sites that show #2. and autozone and advanced auto show it to. it be unameracan to not have #2. i would put JB-weld on the plug. and brass on the water plugs. and dont forget anti-seize compound on all ext bolts and all bolts on the bottom of the truck.

Skynyrd

Ok. What about the oil pan itself? Any pressure there because this leak may possibly be

Coming from oil pan, the bolts were loose especially the rear ones.
One seems stripped.... helicoil. Or tap?
Oil covered pan and everything around. Bottom of pan around the stripped bolt was dripping.
Going to try and tighten the pan. Anyone know what's best for this bolt that's stripped?
Thanks.

Mr.4spd

Helicoil, good stuff. 80psi @ idle is way more than necessary, 15 is plenty. I would venture a guess that the engine is breaking in and the tolerances are loosening up, hence the oil pressure reduction. I personally wouldn't worry about it. Could even be that the oil is diluted with fuel, when was the last oil change?

Skynyrd

, Last oil change was about two weeks ago. The reason for frequent changes is to check it out.

Newly rebuilt with just a dozen or so passes .

Skynyrd

Found the leak.......a bunch of bolts had vibrated loose around oil pan.
Everything back to normal, I hope..

440roadrunner

Rear seal and pan bolts have nothing at all to do with oil pressure, unless you lost so much oil that the oil level is "that low."

Might be a cracked pickup tube

Please do not start any more new threads on this.

https://moparforums.com/forums/f81/440-oil-pump-17765/

Makes things too damn difficult to follow............

Skynyrd

Lol, you got it.