So I've got a 95 4Runner 4WD Auto with the 3VZE. I've figured out that it sounds like the spider gear or something in the rear diff/3rd member is worn and going bad. Axle bearings seem good as I spun the axles with the drums off and could feel a "clunk clunk" from the 3rd member. Anyways, I pulled the 3rd member off my other 95 4Runner (2WD parts truck now, the one that got me started on the yota addiction). Going off the differential codes on the door, that one is a 3.90 whereas the one on my current rig is a 4.88.

My question is will the front diff in the IFS be a 4.88 also? It came from the factory with 31" tires. I've read elsewhere that the differential in the IFS is usually a 4.10 gearing. What, if any, problem would I run into if the gearing is different in the front and rear (obviously when the 4WD is engaged)?

I ask this only because I want to have the gears changed out of the donor 3rd member to a 4.10 since I run 235/75R15 tires right now and don't plan to go bigger since it's a daily driver that only sees light, very occasional off-roading (farm roads, dirt roads, the occasional on road trips to Colorado). I'm the kind of guy who likes to have the replacement part on hand so I can do the swap in a day since I don't have real weekends or can be without my vehicle for more than a day.

Hopefully that wasn't too confusing. Thanks in advance for any info the collective can give me!

Ron

 

they will both be 4.88 in the front and back. and if u try and run it in 4wd it will want to lock up and pop. due to the tires moving at different speeds, also if the 2wd is a 4cly then that diff wont be the right one to go into a v6 housing.

 

Thanks Justin. That's kinda what I was expecting. The 4Runner I pulled the 3rd member from was a V6 and has the same number of "fins" on it too, so I should be all good getting that re-geared.

 

fins as in teeth? if the teeth count are the same then u should be fine with just putting the one from the 2wd in and just bolt it all back together and go.

 

Fins on the outside of the diff casing.

 

4.88 is not stock gearing. V6 auto trannies usually had 4:30 gearing.

 

I thought with the 31" tires they had 4.56 gears?

 

I dunno about that. Are you certain?

:wabbit2:

 

It depends on the Manual vs Auto and 28" vs 31" option packages. It is not dependent upon 4cyl vs V6.

Tranny / Tire 28" 31"
Manual 4.10 4.56
Automatic 4.30 4.88

http://www.4crawler.com/4x4/4R_TechInfo.shtml

I only know because we were in a heated debate on this just the other day...

 

That doesn't explain my factory 4.56s behind my factory automatic that came from the factory with 31s...hmmm.

 

Uhh...no. There were a multitude of gearing options available, 4.88s included, depending on engine, transmission, and tire size.

 

if you can rely on the axle code, you should be able to read the body ID plate. the G144 is the 4.88:1, 4 pinion diff. that was in the '90s trucks with the tire package option.

if you can't rely on the code, get out the floor jack and spin the wheel while counting the d-shaft rotations. THAT'S MY PREFERRED METHOD TO BE ABSOLUTELY SURE something else hasn't been swapped in.

good info here: http://home.4x4wire.com/erik/diffs/#ratios
and the axle code ID chart here: http://www.off-road.com/trucks-4x4/t...ion-18588.html

 

It's a 4.88 since it did have the 31" option. Believe me, I scoured all the links and references I found on here (including 4crawler) trying to figure everything out. I do appreciate the additional education and info. Now, what would be a fair price for a shop to do the regearing on the 3rd member I pulled including all the parts?

Thanks again for all the info.

Ron

 

Yup, those are the links I used and cross-referencing the differential codes from 2 different sites. I will do the spin the wheel while counting the drive shaft rotations as a final check to be sure.

Thanks again!

 

Just because it came with 31s doesn't mean it came with 4.88s. My '90 (sig) came with 31s and 4.56s.

x2 on spinning the driveline to be certain if you haven't already.

 

there is a shop here in seattle area that wants 495.00 i think it was to rebuild the diffs, i think that if u read up on it and get the right tools u could do it your self. its all a matter of finding the specs and staying with in them.

 

Setting up gears is something that should be left to the pros or those who are very mechanically inclined and have the equipment to do it right. Just my $.02.

 

I'm the bringer of bad news....that oem 488 cannot be re-geared....can't use after-market thick 488 rings in your 'differential housing'(3rd) ...the reason being the pinion bore hole is offset closer to the thin factory 488 ring gear. Gotta start looking for a 410 V6 3rd and re-gear that....

 

actually,

after re-reading the O.P., he says he wants to go to 4.10.

so he needs donor diffs front and back that are 4.10, from a v6 so the rear is 4-pinion.

maybe he can trade that front 4.88 for them. anyone?

 

So just to clear things up since things have gotten a little confused since I last checked this thread...

I pulled the 3rd member out of my old 2WD 95 4Runner that's been sitting in my driveway, dead. According to the differential code it's a 3.90, which did come factory on the 2WD autos.

Now, I have my 95 4Runner that's a 4WD auto. The differential code shows that it's a 4.88. 4.88 was one of the ratios that the factory paired with 31" stock tires. Again, I'll be putting it up in the air and do the spin and count to be sure, but unless the previous owner changed out both front and rear diffs (and it was bone stock), it should be 4.88 that's in there now.

So, will that 3.90 3rd that I pulled out of my 2WD be able to be regeared to 4.88? I only threw out the 4.10 regear so I could stay with the smaller tire (cost, etc...)

I do appreciate all the help and comments on this one. Does anyone know of a place that could regear that 3.90 (if it's possible) for me here in the DFW area?

Thanks again!