99 - Front Diff Questions and Concerns

[uzj100]

Guys,

I had a 99 and I broke the front diff climbing a very steep hill. Now I have a different 99 but this one at least this one has a rear locker. I am now a little bit diff shy. Does using the rear locker help to take the stress off the front diff?

Are all 99s front diffs failing in extreme use? Did Toyota start using 4 pinion diffs before 2000, maybe on some later build 99s? Would you wheel the crap out of it and let it break or go ahead and replace it with a ARB locker up there? ARe there places you can send your diff, they set it up and send it back? Raleigh is very limited on locker install places.

This all is coming up because I went to Uwharrie wheeling yesterday and I parked the 100 and rode in a modified 80 with 3 inches of lift, 35s and front and rear lockers. These trucks were basically unstoppable. If I was up there in the 100, I do not think I would be working it as hard with the 99 front diff issue and that on my mind as I wheeled. I feel like I would take it easy on the 100 because of the front diff issue and because I broke one before. Basically being a sissy about it.

Solution
Next Mod - Replace front diff with ARB and then wheel the crap out of it.
Mod after that - sliders
Mod after that - lift

Thanks for the insight.

uzj100

 

[spressomon]

Many threads on this including a recent one that ATS4x4 added some valuable information regarding the proper way to set-up the ARB front locker: PM me and I will forward his e-mail to you with his instructions.

I am getting ready to put an ARB locker in the front of my '99...and considering whether or not I can afford 4.88's at the same time (along with the rear of course). With a diff refresh at over $1,000 + the towing bill when the thing fails it just doesn't make sense to procrastinate installing the front ARB...even if you never use the locker portion...the additional strength alone IMO is worth it. So I would say if you wheel a 100 off-road (and some here have blown the front diffs on very light duty type trails) it just makes sense (from $ point of view as well as trail worthiness) to install the front ARB as soon as possible!!!

 

[LEXUSBEN]

I had the same dilemma you did. Mine is a 98 and I didn't want to wheel it very hard until I put the ARB in. Here's the deal. If you blow the one up that is in there, you have to buy a new 4 pinion diff and the arb as well. If you put the arb in first you don't have to buy the diff you didn't break. Or you can buy Schotts' old 4 pinion carrier and install that - not very cost effective but stronger than what is in there.

I just installed my arb a couple of weeks ago and tested it on the chinamen run we did last weekend. Love it. Can't wait for moab.

As far as installation, I know alot of people don't like to do gear setups. There not bad just have to have a couple of special tools (press and in/lb torque wrench). Arb's people don't like drilling holes in the diff housing. I don't know what kind of shops you have in your area. Slee is out here, I also will offer up to do it (I'm a 10yr toyota, 5yr lexus master tech) I can also probably get a decent price on the ARB itself for you (brother is a toyota parts/arb dealer). Whoever you have do it, the ring and pinion are the same as a high pinion 80 diff, so order a solid spacer for the pinion (replaces factory crush sleve) and you will probably never have to take the diff apart again. Very strong set up. I did this in mine. Don't usually do spacers in the front but this is full time 4wd so it kind of makes it worth it.

Good luck, ben

I'm with spresso, put the arb in now.

 

[cruiser4life]

FWIW, my 98 has the rear locker and I wheel it very hard without much concern for the front diff. Uwharrie, Tellico, Cullowhee, etc. - I don't shy away from any challenge the other guys in 80's, 60's and 40's are attempting.

I feel like I've pushed it to the limit having been stuck and winched out 3 or 4 times in the last few months. I give it hell before giving up and going the winch route.

Knock on wood, but I haven't had any issues. If it does happen to break, I will deal with it then but I've beat on it pretty damn good and things seem to be fine.

I guess I'm in the minority because the way I see it, there's no reason to spend the money until it breaks IMO...

 

[LEXUSBEN]

FWIW, my 98 has the rear locker and I wheel it very hard without much concern for the front diff. Uwharrie, Tellico, Cullowhee, etc. - I don't shy away from any challenge the other guys in 80's, 60's and 40's are attempting.

I feel like I've pushed it to the limit having been stuck and winched out 3 or 4 times in the last few months. I give it hell before giving up and going the winch route.

Knock on wood, but I haven't had any issues. If it does happen to break, I will deal with it then but I've beat on it pretty damn good and things seem to be fine.

I guess I'm in the minority because the way I see it, there's no reason to spend the money until it breaks IMO...

I will add that when I worked at Toyota in LA in the tech services dept, we had 30 front diffs ready to send out to any toy/lex dealer who submitted a warranty claim on these 2 pinion front diffs. The ones sent out were the 4 pinion style. Hind sight I wish I would have grabbed one before I left. Also Motorsports was building up a 99 LC for Ivan Stewart to pre run the baja 1000 that year, his lc also got the updated 4 pinion style. I've also talked to a few people around here and I guess a few years ago there was a huge snow storm in march (about 3 ft overnight) and 3-4 lx's came in with blown front diffs.
Personal opinion - you can wheel them pretty hard its when one of the front wheels comes off the ground and comes back down you have to worry. As long as all the wheels are on the ground its all good. Also this last weekend at chinamen one of the other guys had a 99 100 with the 2 pinion and on one of the obstacles (whale rock) he gunned it. Lots of noise and wheels off the ground and he didn't break. Myself, I fix cars for a living, I don't want to fix mine in the middle of nowhere if I can prevent it.

ben

 

[uzj100]

I want it fixed before it breaks.

Need to order
ARB RD92 front diff - $750
ARB mini compressor - for lockers only - @$150
Solid spacer for the pinion- Where can I order this? and what is the price?

What else do I need for this install?

Thank you,

uzj100

 

[LEXUSBEN]

I want it fixed before it breaks.

Need to order
ARB RD92 front diff - $750
ARB mini compressor - for lockers only - @$150
Solid spacer for the pinion- Where can I order this? and what is the price?

What else do I need for this install?

Thank you,

uzj100

Cheapest place for the spacer is usually Marlin Crawler. You want the one for v6/high pinion. Pinion seal, pinion nut, Optional - main pinion bearing, other pinion bearing, and 1 side bearing (other one comes with arb). Bearings are up to you. I personally did not replace, I run synthetics and bearings showed no signs of wear.

ben

 

[spressomon]

I want it fixed before it breaks.

Need to order
ARB RD92 front diff - $750
ARB mini compressor - for lockers only - @$150
Solid spacer for the pinion- Where can I order this? and what is the price?

What else do I need for this install?

Thank you,

uzj100

You will probably want to replace bearings too. The pinion spacer, according to Darren, is something they machine specifically to this install for the best overall durability. I, with the information I e-mailed to you, would have this conversation with whomever is going to do your install to see if they 'are on the same wavelength'...and if not you may want to look elsewhere for someone that will want to do the job properly...again per Darren.

 

[ShottsUZJ100]

I want it fixed before it breaks.

Need to order
ARB RD92 front diff - $750
ARB mini compressor - for lockers only - @$150
Solid spacer for the pinion- Where can I order this? and what is the price?

What else do I need for this install?

Thank you,

uzj100

Triple locked...your 100 will be unstopable too. I'd not wait until it's too late.

 

[Campfire]

Lock up the front or at least replace the 2 pinion with the 4 pinion. See my nightmare at A Forum Near You! After replacing the front diff, I've had no problem in the mud, snow, or climbing. But I do plan on a locker after the daughter gets out of college...