rear differential possibly bad what replacement should I get?

[K_Labs]

I bought a 4runner with a bad differential or so that's what the seller told me. I pulled the diff drain plug and the oil that came out looked brand new. I'm going to pull the diff now. I was wondering which one I should get to replace it if it needs to be replaced. I know there is a button to the left of the steering wheel that locks the front and rear. How does that work and do I need to buy a specific 3rd member because of it?

EDIT: I pulled the diff. Everything looked fine no damage to any of the teeth on all of the gears ring pinion and I think they are called planetary gears. Put it back in. Gonna focus on the front now.

 

[CruzadoBlanco]

the 4th gen runner have a differential in the transfer case, that button locks that to make it act like a part time 4wd system. the front and rear differentials are standard open with no traction aids build in. the traction control uses the brakes to act as limited slips when that center differential is locked. if the previous owner did not specify which "diff" it was you probably want to check the transfercase oil and see if it will shift in and out of 4wd and if the center diff locks to start with

 

[fdbyrne]

Look at an ECGS complete 3rd member. It should cost less than $700 delivered and people seem to like them.

 

[K_Labs]

It is a very loud and repetitive clunk coming from the back as soon as I start to move. From all of the reading I have been doing it could possibly be a broken ring or pinion gear.

 

[K_Labs]

So it's not the rear. I disconnected the rear drive shaft jacked up the front and put it in drive no movement from the front wheels. Put it back down. When I drop it into 4lo or hit the button on the left of the steering wheel it makes a horrible God awful sound and it's not the front engaging or locking it's something after that sound. I didn't move much maybe a foot or less. Aren't the front wheels supposed to be under power at all times?

 

[NJshadow93]

So it's not the rear. I disconnected the rear drive shaft jacked up the front and put it in drive no movement from the front wheels. Put it back down. When I drop it into 4lo or hit the button on the left of the steering wheel it makes a horrible God awful sound and it's not the front engaging or locking it's something after that sound. I didn't move much maybe a foot or less. Aren't the front wheels supposed to be under power at all times?

V6 or V8? If you disconnected the rear drive shaft but didn't unplug traction control at the master cylinder, the truck will go crazy trying to put power to the rear wheels. In turn, it will not supply much power to the front (if at all). Try unplugging the traction control (gray plug I believe) at the master cylinder and try your test again. This will hold true for V8 all the time or V6 if you put it in 4WD.

 

[K_Labs]

V8 and I didn't unplug the traction control. Nice more fun for tomorrow morning

 

[K_Labs]

My dash is already lit up like a Christmas tree I think I need to do the zero calibration

 

[K_Labs]

OK I pulled a plug still nothing happened. Here is a pic. Also I was able to freely spin the 2 front tires when it was in the air and in park. Is that normal?

 

[K_Labs]

I did the zero point calibration and it did nothing what should I do next? BTW I know it's the front now for sure. Where should I take it in to have it diagnosed? The dealer yotamasters or just start tearing the front end apart and replace whatever I find that is broken?