Norridgewockian
New member
I have a 2001 4runner and the rear axle is building up pressure and making the fill nut leak the fluid out, also the axle is whining when you step on the gas. Any thoughts would be greatly appreciated.
Rear Axle leak and whine.
- Thread starter Norridgewockian
- Start date
Register to hide this ad
RedDragonATL
New member
Your breather must be clogged. It is the little nipple on top of the diff.
Not sure about the whine, but I would assume your bearings (1 side or both) are bad. If your breather gets clogged, it can force gear oil past the axle seals and "foul" your bearings.
There is a great write-up on here re: axle seal replacement.
Not sure about the whine, but I would assume your bearings (1 side or both) are bad. If your breather gets clogged, it can force gear oil past the axle seals and "foul" your bearings.
There is a great write-up on here re: axle seal replacement.
Qyota
New member
Foul the bearings? They are submersed (at least partially) in gear oil all the time. A clogged breather CAN force gear oil past both axle seals and out at the hub, coating the drum and back of tire.
OP - can you describe the whine for us...in detail?
RedDragonATL
New member
Well, maybe foul was a bad choice of words. The gear oil is much more viscous than the grease (not oil) that the bearings are packed in. The gear oil WILL wash out that grease if enough gets in there. If your seals go, bearings are recommended to be replaced. This is from experience, as well as from talking to mechanics.
tbst
New member
So then why did Toyota design it so the greased and oil are in constant contact?
PitbullRescuer
New member
They're not, the seal us suppose to seal the bearing from the gear oil.
RedDragonATL
New member
Yep, what he said. That's what the oil seals are for...to keep the diff gear oil in the diff and axle.
Norridgewockian
New member
I will check for the vent and see if it is clogged. QYOTA, the whine is constant when you step on the gas and will stop as soon as you let your foot of the gas, even if you push the gas very lightly it will whine. I did look for a vent the other day and couldnt seem to find anything, is it right in top or off to a side? Thanks so far for the input!!
004Gunner
New member
I wouldn't go chasing down the whine. It's probably worn gears or bearings and tracking it down could be very expensive and unnecessary.
Gear oil getting in contact with the bearings will foul them up pretty quickly. It's easy to check the bearing once the axle is pulled. If it gets coated in gear oil it's most likely shot so it should be replaced. Machine shops have extensive experience with our axles and are much cheaper than a dealer if you need to have a new bearing pressed on.
badattitude
Member
Going to guess pinion gear on the whine noise. Check diff breather it is likely rusted closed and not venting. You may need new axle seals if your drums have gear oil on them.
The diff breather is on the top center of the axle. It is off to the driver side a little. You should be able to grab the top and move it a little. if it dosen't move easy it is too rusted to vent.
The diff breather is on the top center of the axle. It is off to the driver side a little. You should be able to grab the top and move it a little. if it dosen't move easy it is too rusted to vent.
Qyota
New member
OHHHH, you're talking about WHEEL bearings. My bad. I thought you meant diff bearings.
But yeah, wheel bearings don't typically whine as much as they groan or rumble.
Diagnosing Drivetrain Noise
Norridgewockian
New member
Thanks for the input!! The vent was rusted shut, so I took it off and soaked it in Sea Foam Deep Creep for 10 min and then was able to free it up with some pliers , it is now working great. I will do the vent tube mod that I read about on here so that doesn't happen again. Neither side of my axle seals are leaking so I am guessing that the whine is from the pinion bearing, any body ever replaced that on your own?
A.Wilson013
New member
Norridgewockian
New member
Were did you buy the new union and breather?
A.Wilson013
New member
I have not done it yet, haha. I bought my stuff from the dealer for twice as much as some other friends paid at Autozone.
