"High Speed" oil leak

[mikew]

I usually drive my truck around 2200 to 2300 RPM, it runs great and does not leak.

If I push it to 2500 RPM it belches out a big puddle of oil from the engine rear main seal when I shut it down.

I was discussing it with a diesel mechanic friend of mine who said the crankcase pressure was too high at those higher RPMs, and we came up with a list of horrible things that could be going wrong and causing the problem.

I got to thinking about and old 59AB Ford flathead that I have. Ford always advertised their "road draft" tube that evacuated bad stuff from the crankcase, by the venturi effect, when you were going down the road.

The M35 is supposed to have a road draft tube too, but mine was missing.

I replaced the missing rubber tube and cut a bevel on the bottom end, for a little more venturi effect, and guess what...

No more leaks!

 

[bratpackdad]

hmmmm....I don't have that either. Which motor do you have?

 

[wilber]

My friend just brought home an M35A2 and it ran 2700 rpm and the oil pressure was maxing out the gauge.

His real seal leaked during the drive and immediately after shutdown. He does have the tube. He pulled the pressure regulator off the side of the block and didn't see anything wrong with it.

 

[Heavysteven]

I need a road draft tube as well. What's the id 1 1/4"? How long did you make the tube?

 

[mikew]

The engine is a standard turbo multi-fuel.

The tube is 1 1/4" in diameter and I made mine about 33" long.

 

[gimpyrobb]

Wilber, I bet its his transmission leaking. Smell the fluid and see if its gear oil.

 

[m16ty]

Wilber, I bet its his transmission leaking. Smell the fluid and see if its gear oil.

Gimpy, that's what I was thinking.

This is very common on the deuce. Have too much oil in the trans, go fast down the road, and oil pours out of the bellhousing.

 

[wilber]

Thanks Gents, I will definitely have him check.