Hey guys I just recently noticed gear oil leak in my driveway. While taking a peak under the truck I noticed quite a bit of splashed oil on the underside of the truck bed, a closer look the differential housing is dry, it appears as if its somewhere in the driveshaft U joint (There's a 1/2" hole and its very wet inside on the yolk shaft section. I snapped some pictures unfortunately I was not able to get a close up of the U joint in the way. I don't suspect the front pinion seal is the cause being the pumpkin is bone dry. Is there a seal in the drive shaft? Looking for some help with possibly anyone that has had a simliar issue. Thanks
Here you can see some of the splash of oil it's casusing
Hopefully someone chines in. That is a head scratcher. When my pinion bearing went, it never leaked strangely. Mechanic found the slop when he was repairing my junk e brake pads after they delmainated. It almost looks like it was flinging grease from the U joint. Was the puddle of fluid at the diff? Are you sure it was from your truck?
It looked like yours. You'd be surprised how far gear oil gets flung when the driveshaft is turning. I just put up with it because my lease was almost up. It started showing up at about 60k miles in the back and about 70k at the front.
I'm going to bet it's leaking through the pinion nut. I'd take it off, clean it up, polish surface seal, put a new pinion seal, grey silicone or aerobic sealant on the threads of the nut, and tighten her up back to spec.
Thanks for the replies guys. I crawled under the truck again today and noticed there's theres some up and down play at the yolk. Is the yolk supposed to have any play?
Is the play at the u joint or at the diff? If the play is at the the part where the u joint enters the diff, the pinion bearing is bad. If the play is in the u joint you need a new u joint.
No need to replace pinion unless you hear gear noise or wanting to reratio. At that point, you may as well replace carrier bearings, axle bearings, and axle seals while it's out.
They gotta come out anyway. You basically need to rebuild the whole axle minus gears and carrier....as long as the gears aren't chunked.
It's actually not as hard as it seems.
This definitely has to be from axle seals. I had the same areas splashed as a result. Oddly enough I also had the rear differential issue too. The seals just kind of all of a sudden started leaking and got worse fast.
I have the same issue as the OP - mine looks exactly like the photos. Everytime after hauling a heavy load, I have a puddle under my truck and can see it is leaking between the U-joint plate and the plate of the pinion. I have pulled the driveshaft off and the cavity around the pinion nut is full of gear oil. I don't have any sign of leaking around the pinion seal.
I noticed a little seepage from my axle seal after towing my trailer. I pulled the plug to check fluid and there was a lot of pressure from my breather being clogged. I replaced the breather cleaned off the gear oil and 6 months later still no leaks. I’m guessing from towing and building up pressure it pushed the oil past the seal.