i had recently saw gear oil seeping from my passenger rear wheel so i took the axle out and replaced the seal in the housing i was told that the bearing was bad too but i decided to try the seal first cause the bearing is 100 and 75 for labor it only had slack when it wasnt bolted up when bolted up theres barely any slack and doesnt roar but i drove it 10 miles then pulled over to check for leaks didnt see any so i went to take the plug out to make sure it still had oil and when i almost got it out it shot out like a radiator cap oil wasnt hot. what could cause this pressure buildup or is it normal ive never been in a rearend before its on an 87 single cab 4x4 22r 5spd thanks for any help its been tough project went to 5 shops with the axle and half said bearing was fine and half said it was gone. i caught the leak early cause i park on concrete and when i left out i saw the oil and parked it so i dont think the oil ruined the bearing. thanks for the help sorry bout the long post

 

That's probably why you were leaking around the seal. The vent is clogged.

 

Sounds like your differential breather is plugged. Look for a stubby pipe nipple about 1/2 inch in diameter by 1 inch long sticking out of the top of the diff case. It should have a loose fitting but captive cap on it. Carefully unscrew it out of the diff and clean it up so air will flow through it again. This is also the likely cause of your seal leak; the pressure build up forced the oil past the seal.

It's unlikely this episode damaged a bearing unless you lost most of the oil in your diff.

RJR

 

i took the little metal cap off it had a spring in it do they sell them or is it a dealership part and the oil was still full when i put the new seal on so it didnt lose much

 

since you have it off you can always just replace it w/ a nissan barbed hose fitting that screws into the diff housing and extend the breather with some vacuum hose. This option will cost you about $6

or just soak the old breather in some cleaner(hot water and soap works)

or replace the breather w/ a new one. dealer should have it too

 

that is what i did hooked up rubber hose to the top of the bed but the damaged had been done my rearend was full of water and i had a bad bearing on pass side but i found an axle with drum and all picked it up for 30 bucks bolted it on drained and fillled the diff and back on the road ended up spending bout 50 for all instead of paying 75 for new bearing and having it pressed on

 

i also found out today that my radiator cap was 0.9 psi and the oem is 13 psi what damage could this cause im not sure how long its been this way it has a junkyard radiator in it so i figured they just used the cap that was on it i know the radiator was put in bout 2 months ago