1 year so I had the pinion seal in my rear differential replaced. About a week ago it started to leak again. By day two I noticed a humming sound coming from the rear of my truck. It happens in Between 45-55 mph, and during Hill climbs at any speed. Is this my differential main bearing? The guy might have over torqued the flange nut any help is greatly appreciated!

 

If he over torqued it, it should have failed long ago. It probably wouldn't have lasted a year.

It could be leaking because the flange may have a groove worn in it, the seal was not a high quality one and isn't sealing anymore or your pinion bearings are failing or loose.

If it's making noise stop driving it. Does it still have oil in it? Pull the drain plug and see if there is metal shavings on the magnet. Is the oil very metallic looking?

 

gear oil looks good I just replaced it about 2000 miles ago. When I changed it I didn't notice any shavings. It's very intermittent. On flat land drives it humms for a split second every now and then. But up Hills or hard acceleration it's quite till 45-55 mph then silent. After 55mph I hear it hum when I press the gas. As soon as it reaches speed after hitting the gas it stops.

 

anyone else have this?

 

have you looked at the ujoints? drop the driveshaft and see how they feel, do they rotate cleanly... is the driveshaft damaged in any way.

when he did the seal, there should have been no torquing of the nut required, you simply put it back exactly as it was.

 

I just dropped the axle and drained the pan. My bottom oil plug was full of metal chunks! The oil was full of shavings as well. Still have that hum in the rear end aroun 45-55 and up hills. So now im guessing ill have to take the differential apart?

 

So i noticed metal shaving in my gear oil after a leaky pinion seal, Took the seal off and the pinion was wallering around, i took off the bearing, and in my hand it seems fine, barely any play at all. Same for the rear bearing, but in the case it wallers around, like the flange nut wasnt pulling the pinion bearings forward into the races. any takers?

 

"full of metal chunks" doesn't sound good, but it's a subjective observation, we can't see what you are seeing.

if you gotta pull it for a visual... i like to scrub the middle of the axle housing/third before pulling the third, to keep the crap from falling down into the gearset when the third is pulled... may not matter, if the gearset is hosed.

check those ujoints first.

 

what does this mean? are you asking how to measure free play when it's already disassembled?

did you count the number of turns that it took to unscrew the pinion nut?

 

I did not. However I did take a mental note of how many threads were exposed past the end of the flange nut and where was staked. and yes I'm talking about free play with the flange nut off

 

the only measurements that i know about are when it's assembled, driveshaft disconnected... rotational play and in/out play.

you could check the race/bearing for scoring.

 

So the bearings and races turned out to be completely fine companion flange nut however was extremely over torqued I retorqued tospec. there is no hum at 45 -55 however there is a slight hum 35 for a brief second. There was a lot of metal shavings on the magnet. I'll take it as it goes and check it in a few thousand miles

 

thanks for letting us know what you found.

probably time to start looking for another third, just in case.