1998 3.4 4x4 Bad Differential... 3.91 gears WTD

I bought my 1998 tacoma back in 2018 with the 3.4, 4x4, 5 speed and 3.91 gears sitting on 33x12.50s. It had 155k miles on the dash and I was stoked to find one with low miles in the south (no rust issues). It now sits with 225k miles when low and behold, the rear diff decided to shit the bed. Initially for about 70k miles the truck would have a "clicking" that only happened while turning; I replaced my ujoints and would grease quite frequently. More recently I was making a tight turn in a parking lot when I heard a pop and now she sounds like an empty shopping cart going down the road. Its sitting over at my local shop who has diagnosed it as a bad differential, "Chipped Gears". Unfortunately I have come to find out how hard it is to track down a 4x4 rear end with 3.91 gears for these first gen Tacomas... Anybody else been down this road before?? Looking for advice... Should I pickup new gears and regear my current axle?? What could've gone bad in my diff?? Thx in advance...

 

Any tips/ideas? Not sure what can go wrong in a differential and I don't want to buy a new set of gears only for the Diff to still be bad... Not sure what goes "Bad" in a diff... Any insight greatly appreciated.

 

Just buy new gears.

Match your current rear end, or order for both the front and rear and regear.

 

3.91's with 33's?!

Most folks are running 4.56's or even 4.88's with 33's...

I have 4.10's and 32's which is adequate, but I'll probably go to 4.56 when I get 33's.

 

a tooth on a differential gear being chipped is one thing, a chipped tooth on a ring/pinion is another. If there is damage inside the carrier where the differential side gear rides, then yes, the gear carrier has to be replaced. This is caused by excessive spinning of one wheel. Techs want to do the “whole” job, i.e. replace the assembly as opposed to just putting in differential gears. Yukon makes a diff gear kit, it isn’t cheap, just under $300 or if you can find a used diff just use the diff gears out of that.

 

Haha yeah she runs about 3100rpm Doing 70- 75 mph. I guess it wouldn't be a bad idea to re-gear.

 

This is what I was concerned about, unsure if it's a differential gear that's chipped or something inside the carrier. I do recall the shop mentioning something with my ring and pinion but I will have to wait for them to open backup from holiday so I can clarify what exactly went wrong in my diff aside from "Bad Diff, Chipped gear, ring and pinion" Thank you for your insight I will Update this thread as I go