Rear diff help

[Allclock]

Hi All, I am new to the diff world and am looking for a little help. I have a 98 4runner with 260,000 miles and started getting a howling noise a few months ago. I changed the gear oil to mobile 1 syn and it has been ok for a while. No leaks that I have noticed. I will be giving it a much closer inspection as soon as I get it into my garage.
Last week as I was coming home from work (30 miles) I heard the tire scratch the street as pulled into my drive way. I parked it, had dinner, and about an hour of cool off time I checked it out. Seemed to back out of driveway ok, drove around the block ok, and reverse ok??
I drove to work again the next day and it screeches the tire as I make a left turn into work parking lot.

Rear tire seems to be locking up when it gets hot. Seems worse while making a turn.

My guess is Diff is cooked and needs replacement. Any trouble shooting suggestions? I have heard wheel bearing suggestion also. I will check for play in the wheels, but I am pretty sure its the carrier.

Thanks, "FNG"

PS Thanks for helping me get through the "pink milkshake"


EDIT- 98 limited 3.4, auto, e-locker, not sure ratio yet. As From factory with towing package

 

[badattitude]

I bet your synthetic diff oil leaked out the axel seal and is making your rear drums sticky. You should look at your rear brake shoes for signs of gear oil.

Have you ever replaced your axle seals?

Have you checked your diff breather, maybe it's rusted or otherwised clogged causing pressure to build in the diff.

The holwing could be the pinion bearing going bad. It is the first sign if you have run low on gear oil, becasue it is leaking out the axle seals.

I would call East Coast Gear Supply if I needed a new diff. Get a new one with a True Trac installed.

just my .02

 

[Jon]

Welcome to the club! All good things to check.

If it ends up being a wheel bearing I highly suggest getting one from NAPA, it's the original part, cheaper and has lasted the longest for me compared to junk from AAP, AZ, or O'reily.

If it's rear brakes....I'd replace all hardware, shoes, wheel cylinders and get the drums turned or new ones. I just did a full rebuild with new parts all Duralast, surprised by the good quality.

Next time you go for a drive 10min or more check that wheel for heat. That will be a dead give away for brake or bearing failure. The diff is going to be hot/warm no matter what.

Check the door jam for gear ratio, more than likely a 4.30.



Good luck.

 

[nevada]

i doubt its in the diff.
probably a wheel bearing, or brakes as mentioned above.

 

[Allclock]

Thanks for the quick reply. I will inspect fluid level in the diff and look for signs on the drums. Last time I looked it didn't look like rear seals were leaking. I will definitely check again.

Any advice on how to tell the difference between needing wheel bearing or new third member?

 

[Allclock]

Thanks for all the replies!

 

[Jon]

Jack the rear up at the diff so both wheels are off the ground. Stick it in neutral and try to spin the tire by hand. It should free spin with no noise, besides minor drum/shoe contact, MINOR. Then grab the tire at the top and shake in and out to check for wobble, indicating bearing ware.

Here's what the bearing being torn to shreds sounds like Blown rear bearing Toyota 4Runner - YouTube