Athansinis

Hello All,

I finally took my truck to a mechanic for a noise that has been bothering me. Turns out it is the rear differential. The quoted price is approximately $700 for labor (which, as I understand it, would be a full rebuild of the differential, so this could go down a bit) + parts (including both axle seals and the parts needed for the rebuild). It sounds like the estimate on parts could be as much as $1,200. I've heard this shop does quality work but I'm wondering if anyone can suggest other options?

Is there a reputable place that will build or rebuild a differential? I was looking at Marlin Crawler, but I can't afford (time or money) to redo the front gearing and it looks like they don't have a stock gearing option for my T100.

My plan for this truck is to turn it into a mildly modified expedition vehicle (33-ish” tires, sliders, winch, rear locker, etc.). So a reputable place that would rebuild my differential with quality parts and a locker would be great.

Finally, I'm fairly mechanically-minded and I have most basic tools. I have no intention of trying to rebuild the differential myself but are there any special tools I would need to remove it and reinstall it if I sent it out?

Thank you very much for the help.

millball

Pulling the 3rd member is fairly simple and requires no special tools.
You ought to be able to source a good used 3rd for a couple hundred bucks.

250000_yota

I see your in Colorado Springs. Head up to denver and check out yota Jim's or the yota yard. Either will have a new third member that will work for you. As millball said, pulling your third is fairly easy. Pull it out, figure your gear ratio out. You can get it busy counting the teeth if the ring gear, and divide it by the number if teeth on the pinion gear.

Athansinis

Thanks, I will definitely look into that, but I am a bit worried about putting something used back in and I'm also not sure what to look for in used differential/third member. I'm starting my doctorate at UCLA in October so I am not going to have much time to fix anything that breaks (and what time I do have I'd rather be out exploring). For that reason, I'm hoping to get everything in very good running order before then. Any ideas for sending it off for a rebuild if I go that route?

On the subject, are you happy with the Truetrac? I'm interested in going with one but I have heard slightly mixed reviews on the durability of the Eatons. Also wondering how it does in snow and ice?

Thanks again to both of you.

scuba

ECGS probably has 4.10's for the t100.

dropzone

iTrader: (6)

Looks like you have other stuff to drive. Consider shipping your third to Zuk at gearinstalls.com

You can get your rear third out in less than an hour.

250000_yota

My Trutrac has put up with everything I've thrown at it, and trust me, I'm not exactly nice. I have zero complaints about it. It is very forgiving I slick conditions, which is one of the reasons I picked it over your standard LSD or locker.

Athansinis

Thanks for the suggestion. I got in touch with Zuk and I think I am going this direction. Hoping to get it out this weekend.

Another question for anyone.... I'm not positive if I have the 4.10 or 4.30 axle ratio, so I'll count once it's out. Nitro makes the 4.10 ring and pinion, but the only 4.30 I've found has been an OEM good condition used from justdifferentials.com. Anyone have any idea where I might be able to find them new?

Thanks again, all.

250000_yota

Have you checked eastcoastgearsupply.com or Randy's ring and pinion?

-edit- never mind. Just looked. Looks like either 4.10 or 4.56.

noahrexion

If you have an auto, you've 4.30 if you have a 5speed manual then you have the 4.10

I too just replaced my third with a unit from East Coast gear supply - it took about 2 weeks to get but I'm very happy with their service overall. I ALMOST had them add a truetrac, don't make that mistake (do it).

Athansinis

I'm a week behind but I finally got the third pulled. I discussed some options with Zuk (gearinstalls.com) and decided to go with the Kazuma TRD limited slip differential. For my use, I think it will be pretty perfect and for $299, the price was right.

My T100 is an automatic, but it appears I have the 4.10 gears. I bought the truck with about 65,000 miles so I can't imagine that it wasn't original, but who knows?

ZUK

iTrader: (1)

This thread is now officially in danger of being a picture intensive monster. Dial up is not recommended. ZUK

Athansinis

I'll start with a few photos. Unfortunately I did not take any photos while pulling the third. So here's the truck as it sits now. I'm trying to slip under the HOA's radar, so I put it back together with the hope that they won't notice it's actually on jackstands (rear tires are hovering about 1/2 inch above the asphalt.







Hopefully the plastic wrap will keep dirt out of the housing.



Getting ready to ship it off to Zuk!





I apparently forgot to take a photo of it packed and ready to go, so I will leave it at that.

ZUK

iTrader: (1)

Good news Athansinis....the ring/pinion is still in great shape and the pinion flange is also very
reusable. I have not received the master kit/solid collar/Kazuma LSD yet but I understand they
will be here tomorrow afternoon.
You said in your email the shop diagnosed the noise as coming from the 3rd member. Well, I don't
see enough going on here to really cause much of a noise. Granted, all 4 bearings seem to have
alot of wear and tear on them but nothing is outright wobbly. Describe your noise a little more?






...................




wow....nice job making sure the gear oil did not leak.



Pinion preload check....no preload and it turns real easy but is not wobbly. Bearings are old
and that is expected.



carrier bearing preload check.....none found. No preload left after so many years and so many
miles but at least it was not wobbly.




backlash check.....wow....looks good. I measure about .006" around the ring gear. Not bad at all.




pattern check---DRIVE----a little shallow but that is expected with worn pinion bearings. With a
new bearing the pattern will look great.



Coast side----again, it looks shallow but the worn bearing does that. It will be good as new with new
bearings. No damage to this ring and pinion.



Factory staked nut




Wonder if I can hold it with 2 fingers and the electric impact take it off?




Guess so




Is the flange ok to re-use? Gonna clean the grease off with starting fluid and use WD-40 with some
1000 grit sandpaper and see if the seal surface is still good.



Looks great. What you see in the pic is not a groove of any sort....I cannot feel any marks and it
looks great This flange is AOK.

Athansinis

I'm avoiding studying for a test and decided to check out the forum and look what I found! I'm really happy everything is reusable but I am a bit concerned now what my sound is. The sound is sort of a high-pitched whirring noise. My original guess was wheel bearing, but the shop that I hear is supposed to be so good said differential (both the tech and the owner came to the same conclusion supposedly). I guess I will get it all put together before I get too frustrated though.

Thanks for the photos!

ZUK

iTrader: (1)

What is the total mileage now?....and is the high pitch noise on acceleration or de-accel?
Does the noise change or constant? Speed dependent noise?

Athansinis

Total mileage is 93,000. In the past 4 months I have only driven the truck back and forth to the mechanic (so about 6 miles total), so I am not sure I remember the exact conditions for the sound. I could definitely hear it all the time but I don't remember if it changed with acceleration or deceleration. If I get the third member back in and it's still there, I will definitely figure out exactly what it does and doesn't do. Thanks again for your work!

ZUK

iTrader: (1)

Pretty low mileage for a 1995 model. The bearings feel to me like they saw 200,000 miles....
maybe bad gear oil will do that. Just guessing. Talking about guessing....maybe the small outer
pinion bearing is chunking out and that will cause a whistle. I'll know when I tear into it.
So, today I received the Kazuma. The master kit apparently needed my signature so tomorrow
will be the rest of the stuff.

ZUK

iTrader: (1)

More pics....





chromey look of where the small outer pinion bearing was riding.....hard to see in this digital photo
but the rollers of the BIG pinion bearing had a bluish tint to them indicating heat was involved.....
old bad oil or ran low on oil sometime in the past?



Closer look at the blue rollers of the larger inner bearing. I tried different angles to make
the blue more obvious but it didn't work.




removing the old seal with the special seal remover tool....




The old crush here was cleaned off with starting fluid to look "more presentable"....it had a
black oil on it.....also had a reddish rusty looking goo on the inside. Not sure what that was about.
Note----All the 8.4" diffs come from the factory with a crush and two .032" shims. So maybe that
dispels the rumor that it's "bad" to use shims with a crush




The small outer pinion bearing rollers also showed signs of bluing and heat.

ZUK

iTrader: (1)

Received today.








T100 master kit and a solid collar. This product was from http://justdifferentials.com I'm planning on
being up at 330am to get an early start
on Athansinis's 3rd.
ZUK