Cummins V504C leaks a lot of oil from transmission end at high RPM

Are you just hoping for an answer other than the rear main seal?

It could be a lot of things besides rear main seal.

But the rear main seal is still the most likely place . There are other possibilities , are there any oil lines in that area ? A cracked fitting could open up under higher oil pressure .

Is there any place in the oil lines where you can add a known good oil pressure gauge? I suspect the the pressure regulator in the oil pump is stuck closed, so excess pressure can be bypassed back to the sump.

Paul

I sincerely hope you find something else, something simple and cheap!

I think so. How about an oil passage plug leaking?

This just in:

I have a sunburn on my chest today. 'Tis good that I had only a little bit of TIGgin' to do, as it went right through my shirt. Methinks I'll be wearing the leather apron next time, despite the heat.

We spent some time investigating today.

One place that was leaking was in the oil pan gasket.

Also the air compressor in front.

I also noticed, but did not investigate, that the reported oil pressure was kind of high. I am purposely not posting numbers, as I first want to ascertain what is going on.

HaHa!

"Sorry, can't talk about that" will be my reply next time somebody asks me about a pressure reading.

Sorry. I forgot the numbers and did not want to guess. It goes up to

By the way, I just came across an advert selling a rebuilt V504C... for $10,000 :-)

My best guage experience was one that was attached to some small crappy compressor that vibrated so bad the hand actually broke off. The counterweight part of the aluminum stamping was still there on the small shaft- just the pointing part broke right off.

Oh, and the guage was new and broke in a matter of minutes.