I had a leaky rear diff on my 2002. Guy welded a cover on. All is well until about 500 miles later I hear some noise from the rear end. I drained the fluid and it was black as tar. AND....only 2 qts came of Amsoil 75w-90 came out.
I refilled with more Amsoil and the noise did not go away. Mechanic said he would make it right. He told me to keep driving it until it got louder as that would help him ID the bearing(s) that were bad.

Here's my question. How should I go about having this repaired properly. Can he just purchase the bad bearing(s)? Do I need to get another rear end? What should I expect?

Replacing any of the differential bearings requires disassembling it which means the backlash and gear pattern has to be redone. So with that being said I would tell the mechanic he owes you a rear differential. If it;s still leaking I would see about souring an entire rear axle with differential.

Leaking fixed. I’m not liking your answer. LOL

He’s had it for almost 2 months. Hasn’t started on it.

2 months and no work, what is he, a building contractor, they're the ones who usually do that to people so they keep working 8 jobs when they should be doing only 1.

I'd feel like he's screwing me around and be big time upset....

Yep, that’s how I feel.

Black gear oil means it's been burnt and can no longer do it's job to lube and cool.

The gears will eventually fail if it was driven with low, crap oil for any length of time.

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Here's my suggestion, get your rig out of that shitty shop.

Next, contact ECGS (East Coast Gear Supply) and order a prebuilt unit. They send it to you, you remove yours and send it back to them to satisfy the core charge. Easy Peasy!

Removing a rear 3rd member isn't hard. I have this video you can use to get it done. If you have an e-locker, you'd want the locker in the locked position before pulling the diff. You can remove the e-locker motor before or after you pull the diff, your choice.




If you wanted to know the amount of work that goes into rebuilding a rear diff, check this video out I made with ECGS.




This is the opportune time to re-gear if you've been considering it. If you want to know what it takes to pull the front diff, watch these two videos. We struggled in Part 1 so we made a Part 2 to showcase some techniques to make the job of pulling and reinstalling the diff much easier.






Finally, if you want to know the work that goes into rebuilding a front diff and installing a locker, check out this video we made with ECGS.

I’m calling ECGS right now. I’m picking up my 4Runner this evening. Great advice mtbtim!!!!

I've bought a few diffs from ECGS, quality operation that warranties their work for 5 years.

Install is pretty straightforward, good opp to clean up your rear axle, brakes, seals, bearings, etc

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It's clearly Halloween themed, I see no issues. If it was December however...

mtbtim, thank you, thank you, infinity....

Just talked with Thomas at ECGS. They are only 2 1/2 hours from me. He took me through the ordering process. I am picking up the 4Runner tonight and will know what ratio I need to order. Thomas was great in explaining everything. Total price out the door including install approx $1350. He said should take about 3 hours and I would be headed home.

I'm gonna let them do the install (will cost about $400 or so) and then have the confidence it was done correctly.

My mechanic had done some other work and just texted me "no charge." He's a great guy. He works out of his home and just couldn't get to the rear diff. I don't know how I feel about me paying for it all. I'll just pray and see how everything unfolds...

Thank all of you! Problem solved!

The mechanic welding the leaking axle housing probably didn’t cause the diff failure, I bet it was already on its way out from being low on oil due to the leak

The leak was just a pinhole at the top of differential. It “never” got low up until the mechanic only put 2 qts in after the welding job. I know the welder did nothing wrong. The mechanic said I only gave him 2 qts. Obviously, he didn’t check it after attempting to fill it up.

I went back to my case of gear oil in my garage and 3 qts were gone

This is why I always do the work/check the work, people make mistakes, often honestly, but it's still my vehicle.

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Something as simple as putting fluid in diff….

I never would have checked behind “him”.

A chimpanzee with below average intelligence should easily perform this task. Fill til it comes out the hole.


But I trusted this guy. $1300 later. Hmmmm…..

I just got back home. He didn’t even come outside to meet me. He texted and said the keys were over the visor. I’m gonna have a beer or two and watch Tucker Carlson and round it out with a chopped BBQ.

Reflect and try to do the right thing. I’m not sure what the right thing to do is.