Leaks Under Load

[Ptothej]

I recently started to find my leaks under all of the gunk build up on mostly the t-case. I cleaned it off and found there to be hardly any leaks, and it stayed quite dry for the most part until... I loaded up my 5000lb boat and took off for the lake at 100km/h hitting one major hill in fifth gets my egts hot and nets me about 25psi I checked my leaks after the round trip and yep its started to leak decently between the tranny and then not the output shaft seals but the inspection plate? plus fill and drain plugs. Yes its a one owner and dude claims the clutch has never been done aka nothing has ever been apart, so seals are getting old at a million km's give or take, but like I said it seems to stay dry until I load her up, am I overheating the drivetrain, is the vent hose not venting possibly? Ideas? Has anyone come across this?

[KTA]

Probably your bearings are worn enough that under load it deflects the shafts enough to cause the seals to leak from to much run out.

[Ptothej]

Ill take that answer.. thanks!

[ciamcoop]

My rear diff does that. Normal daily driving it's clean n dry, hook 10k lbs to it and drive 50 miles and it's dripping from the pinion. Vent tube is clean, has 238k miles on it.

[93DodgeCummins]

I think i have a similar problem... I pulled my 9000 pound camper 600 miles round trip and when i got down there. There did not appear to be any oil dripping on the ground from the Getrag. When i got back home i let my pickup sit for a few days and i noticed there was oil on the ground from the transmission area. So i got under and looked and there was oil everwhere under there. It looked like it might have came from the output on the getrag. I checked all my fluids and they were fine which kinda lost me. Is it hard to replace those seals or do i need to? I am kinda wondering if the leak will stop when i dont pull anything.