100 Series Front Diff Failure - Random Chat

[ga12r1]

I asked this in another thread, but seems more appropriate here:

What’s better? ATRAC with the improved 4 pinion front diff year 2000 and beyond, and add air-lockers if needed? Or is the stock ('98-'99) rear locker good enough and change the 2 pin to 4 later? (Seams valid either way).

Also, I am guessing, that if you have ATRAC, it does it’s magic up and until you press the air locker button.

Meaning that if you have an air locker in the rear, lock it for an obstacle, that ATRAC keeps working in the front (but not rear while air locked), and goes back to normal operation when unlocked. So you have the best of both worlds (if willing to pay for an air locker)?

Then getting back to the ‘98-‘99 stock locker. Is it good enough? But should you replace the front diff to 4 pin instead of the original 2 pin? Seems like you need to spend $ either way, and you get onboard air, if you go the ATRAC route, and add an air locker (if all my above operational assumptions are correct).

TBH they both suck. I wouldn't shop for 100 based on 2 vs 4 pinion. If you find a 98-99 you like get it. If you find a 2000+ you like get it. Simple

 

[CameraCruiser]

TBH they both suck. I wouldn't shop for 100 based on 2 vs 4 pinion. If you find a 98-99 you like get it. If you find a 2000+ you like get it. Simple

I’ve pretty much come to that conclusion. If I get a 2000+, then I’ll just add air and a locker if my wheeling grows in that direction. Obviously it will take some fateful trip that will make me wish I had it sooner.

 

[kevgentile]

TBH they both suck. I wouldn't shop for 100 based on 2 vs 4 pinion. If you find a 98-99 you like get it. If you find a 2000+ you like get it. Simple

Agreed 100%

I wanted a later 5 spd but came upon a clean '99 with a super clean rust free chassis for $4k. Haven't had a moment of regret.

 

[Blue Phoenix]

I guess I'll add myself to the registry. 2006 LC, mods in SIG

Situation: slurry of snowmelt/ ice combined with fairly deep pebble bed. If I had to guess, after the truck lost momentum and my right foot reacted accordingly I was probably running between 3-4k RPM when my glorious TOYO MT caught traction on the ice shelf ahead of me.

Damage: Ring and pinion

@cruiseroutfit I've actually been looking at your website and pondering my next step while I stare at my old diff in the garage. I'm trying to convince myself I don't need a front locker (or rear for that matter). I'm also looking at how much sheet metal I'd have to cut to fit 38's like @benc , so there's that.

 

[SaturnAscends]

I’ve pretty much come to that conclusion. If I get a 2000+, then I’ll just add air and a locker if my wheeling grows in that direction. Obviously it will take some fateful trip that will make me wish I had it sooner.

I've done a bit of research and the consensus seems to be that the ring a pinion are simply too small for a truck of this size and weight. I’m not sure adding a locker would help much, since these parts would be reused. I suppose a 98-99 would be more likely to break the ring gear, but this doesn’t appear to be the most common point of failure (I could be wrong here).

I’m just speculating here, but Toyota may have switched to 4-pinion in 2000 to help the front diff cope with the added stresses of ATRAC. Perhaps they underestimated how much it could shock load the ring and pinion however. See the case above: I wouldn’t say it being 4-pinion helped in that case.

 

[Zjohnsonua]

Most recent diff pop we received was interesting in that it looks to have been an OE build, 300k miles, and the preload washer plate slid right out. Zero pressure. 2002 model.

Kurt's guys provided the pieces to repair. It'll go back in with a bit more preload this time.

 

[plainjanefjc]

Does a locker seems to be making these last longer?

 

[cruiseroutfit]

Does a locker seems to be making these last longer?

Yes!