Repair or replace rear differential in '02 4Runner? (1 Viewer)

[marcfj60]

I finally got around to trying to diagnose the howling noise in that '02 4Runner a picked up several months ago. I need to get it fixed and running so that Colin has something to drive to CNM/UNM once we move to the new house in Sandia Park in January. The PO towed a trailer that was way too large with this 4Runner for too long and it already got a new transmission and transfer case. I knew about the possible rear diff replacement when I bought it which is why I paid $1,500 for it.

I pulled the rear diff drain plug and discovered some metal flakes stuck to the magnet in the drain plug. My dad was helping and he's a retired mechanic so he added to the diagnosis (and hindered productivity with his commentary). The appearance of the flakes indicates spalling of gear faces. What I need to figure out now is the best route for repair. I'm not in the mood to pull the differential and try to rebuild it myself. I wondered if there is a resource in town for purchasing rebuilt complete third members, if I should order one from JustDiffereantials (or elsewhere) or just go super cheap and get one with unknown history from the salvage yard. Or should I go see what I can get with the MUD discount at AmToy?

 

[pappy]

Finding a diff at the upull is tough.

Can you pull it, and take it to U-Joints for repair? Kurt at Cruiser Outfitters can sell you the parts (ring, pinion, install kit).

 

[yotamotive]

The 3rd will have to get taken out regardless, unless of course you can find a complete axle in good shape. You could remove it and ship it to Zuk. He would get it set up right. gearinstalls.com

 

[Tank5]

I have a ring and pinion set for a toyota 8" diff that came out of a tundra. I need to check the gear ratio. I also have a complete carrier for it too. If you can use it you can have it for a 6 pack.

 

[marcfj60]

The 3rd will have to get taken out regardless, unless of course you can find a complete axle in good shape. You could remove it and ship it to Zuk. He would get it set up right. gearinstalls.com

The biggest complication right now is that I'm doing this in the dirt, outside. So I'm reluctant to remove parts and then leave a hole (even if it's covered and taped) for an extended period of time. But if that's the best route, that's what I'll have to do.

 

[marcfj60]

Finding a diff at the upull is tough.

Can you pull it, and take it to U-Joints for repair? Kurt at Cruiser Outfitters can sell you the parts (ring, pinion, install kit).

If you've got experience and confidence with U-joints, then this seems like a decent option, leaving the hole in the axle housing covered for as little time as possible, short of just buying a $1,000 rebuilt unit from JustDifferentials or something similar.

 

[marcfj60]

I'm assuming this is also a great time to replace axle seals.

 

[pappy]

FYI, there is a 2002 and a 2004 4Runner in the boneyard. Both have been there 3 months, so probably picked over.

 

[Montijo505]

I don’t know how you feel about eBay but a quick search turned up several complete rear diffs for under $500. Good luck!

 

[marcfj60]

I guess now I just need to figure out what axle ratio my 4R has. The axle code says A02A which so far seems to be 3.91 gears based a limited web search. Too bad there are so many different opinions on the various web forums.

 

[Chompers]

FWIW, when I destroyed my front diff, I found all sorts of conflicting ratio info on the web. My sure way do find out what I had was to count teeth! My solution was Ebay, I didn't have the desire to go spend hours at U-pull. Good Luck and happy wrenching

 

[SteveLCetc]

Chock the front tires, raise a back tire, put it in neutral and count the revolutions of the driveshaft for, e.g. 5 revolutions of the tire. Then divide by the e.g. 5, and multiply by 2 because only one tire is turning...

 

[marcfj60]

I haven't called U-joints yet but wondered if anyone has experience with TRANCO. They list differential repair on their website.

 

[pappy]

I'm familiar with Tranco, but have no experience with them. I drive by their shop several time a month. Their shop from the outside appears to be well organized and uncluttered.

U-Joints built the diffs in the FJ40, and the diffs in my 4Runner. They also did the diffs in my 1985 xcab. I've never had a problem.

 

[marcfj60]

I'm familiar with Tranco, but have no experience with them. I drive by their shop several time a month. Their shop from the outside appears to be well organized and uncluttered.

U-Joints built the diffs in the FJ40, and the diffs in my 4Runner. They also did the diffs in my 1985 xcab. I've never had a problem.

With that level of experience and satisfaction, I can't see a reason to go anywhere else.

 

[LX450JC]

There are a couple of 4runners being parted out on Facebook.I would reach out and see if they have the correct gear ratio and just buy the third member to swap.

 

[alia176]

There's a complete 2002 4runner body that someone is selling completely intact. He is using the rest for a rock crawler project.