Oil leaking from rear tires/ loud whining

My truck is leaking oil from rear tires and making a loud whining noise... We've replaced bearings, twice....Any thoughts on what it could be?

 

Welcome to TacomaWorld
Didi you replace the differential vent?

 

last time i had oil coming out of my tires the axle seal was non existent

 

Did you have a shop replace the bearings, or did you do it yourself?

If it was a shop, then it's time for a new shop.

There are several little nuances when replacing the bearings, retainers, and axle seals, which if done incorrectly will result in repeated seal failure.

 

With oil on the rear tires, it is surely your rear axle seals. And the sound you are hearing is your bearings. Both need to be replaced (again, it seems).

Not sure the process you used before, but here's a write-up that goes over all the tools and parts you need to make it a "reasonably straight forward" job. The write-up also talks through some of the "gotchas" and "tips" to make the job more successful.

Step-by-Step Replacing Rear Axle Seal & Bearing w/ABS (1st gen Tacoma or 3rd gen 4Runner)

and here are photos of the process, in action, twice:

• Replacing My Rear Axle Seals & Bearings on a Toyota 4Runner (also Tacoma)
• Rear Axle Seals – This Time on the Tacoma

​

 

If you replaced your bearings but NOT the seals, there's your problem.

They can be easy to screw up, from what I've heard, but @turbodb knows a thing or two, so he's got a good write up.

 

You sure it’s not a wheel cylinder.

 

Check your brake fluid level. Although the whining sound says bearings.

 

Sounds like rear axle seals. They not only need to be changed when doing bearings, but have to be very careful not to screw up the new seal when reinserting the axle shaft. Had the same thing on mine. Resulted in brake chattering as well.

 

ABS axle?
I’ve run into this problem twice now, there should a small spacer between the abs tone ring and the bearing retainer, about 1/4 thick or so. If it’s left out when doing the bearings the tone ring and it’s retainer are pushed to far down the axle and the retainer that is supposed to contact the inner seal doesn’t. Remove the ABS sensors and look in to see if the tone ring is centered in the hole, if it’s not that’s probably your problem. Took us a while to figure it out the first time, truck had been to two shops before us.

 

How sure are you the whin is coming from the wheel bearing. It's very common and often overlook is the carrier and pinion bearing that whin. As far as the oil leak, you sure you don't have a bend housing or shaft?

 

spin the wheel and make sure your axle isnt bent, i had that issue on mine and wouldnt stop leaking.