Toyota third set up

CarolinaCrawler1 · Aug 30, 2017

I'm getting a rear axle together for my rig and was wondering if yall know any tricks to setting up a 8" or 9.5" third for hard use? My rig is a trailer queen so no need for high speed worries (it is a toyota after all). Ive always heard a properly set up diff will brake 30 spline RCV's. What do you do to get it like that? Is anything to do to help it hold up when you are pushing the limits?

BUG-E J · Aug 30, 2017

CarolinaCrawler1 said:
I'm getting a rear axle together for my rig and was wondering if yall know any tricks to setting up a 8" or 9.5" third for hard use? My rig is a trailer queen so no need for high speed worries (it is a toyota after all). Ive always heard a properly set up diff will brake 30 spline RCV's. What do you do to get it like that? Is anything to do to help it hold up when you are pushing the limits?

Have the gears heat treated and cryoed. Use an install kit with new bearings. Pay somebody that knows how to set up gears to do it. I beat the hell out of 5.29s and 39.5 iroks

84mallcrawl · Aug 30, 2017

solid pinion spacer

clemsonjeep · Aug 30, 2017

What BUG-E-J said is right on. If you set them up just get the backlash on the tight side and the depth a little deeper than a daily driver. You just want to make sure youre taking full advantage of as much of the gear tooth surfaces as you can. The use of a solid spacer on the pinion is a no brainier.

The cryo and heat treatment may seem questionable but just do it.

TBItoy · Aug 30, 2017

solid pinion spacer, good bearings, LOTS of carrier bearing pre-load, touch deep on the drive side with minimal backlash.

Run V6 drop outs for the stronger casting and bigger bearings. or a HP in the front preferably.

You'll break 30 spline chromo birf, rear shafts, and twist the actual pinion shaft off next.

I hear that ECGS builds a good strong Toyota diff, especially if you tell them its for crawler/offroad only use.

karatejosh · Aug 30, 2017

Re:

Ecgs did mine and dared me to brake them no failure yet with a turbo 4 banger and 37 reds last month i blew the diff clean out of the axle and nothing broke other then every studd on the diff lol

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BUG-E J · Aug 30, 2017

I ran a v6 chunk in the front and a taco rear. And yeah I didn't mention the solid but that's a must

alscott · Aug 30, 2017

The best thing you can do if you can afford it is have ECGS set it up and get the 5 year warranty deal. I broke my ECGS 3rd four times and they fixed it every single time no questions asked. All I had to do was pay shipping to them.

dwa2469 · Sep 5, 2017

BUG-E J said:
Have the gears heat treated and cryoed.

Where would one have this done?

mashyermotor · Sep 5, 2017

Re: Re: Toyota third set up

dwa2469 said:
Where would one have this done?

RCV

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clemsonjeep · Sep 5, 2017

TBItoy said:
LOTS of carrier bearing pre-load

Exactly...I remember reading up on gears prior to setting my the yota 3rds in my rig. Previously I had only worked on Dana style axles. I came across one guy online...can't remember his site or name, but the thing that stuck in my head was him saying over and over that you could not physically get the pinion nut too tight with the solid spacer. If I remember correctly he had a picture of his 3rd in a mount with a really long cheater on a wrench with him standing on it.

BUG-E J · Sep 5, 2017

clemsonjeep said:
Exactly...I remember reading up on gears prior to setting my the yota 3rds in my rig. Previously I had only worked on Dana style axles. I came across one guy online...can't remember his site or name, but the thing that stuck in my head was him saying over and over that you could not physically get the pinion nut too tight with the solid spacer. If I remember correctly he had a picture of his 3rd in a mount with a really long cheater on a wrench with him standing on it.

I busted one with a half inch impact

TBItoy · Sep 5, 2017

clemsonjeep said:
Exactly...I remember reading up on gears prior to setting my the yota 3rds in my rig. Previously I had only worked on Dana style axles. I came across one guy online...can't remember his site or name, but the thing that stuck in my head was him saying over and over that you could not physically get the pinion nut too tight with the solid spacer. If I remember correctly he had a picture of his 3rd in a mount with a really long cheater on a wrench with him standing on it.

ZUK gearinstalls.com

side spanners for the carrier is what I was referring to, I put 250+ ft-lbs on the side spanners on a v6 third

, but yeah, with a solid spacer in the pinion you can just tighten the **** out of it. Red or green loctite and then stake it. It just make the inner races of the pinion bearings a set distance.

Supposedly a crush sleeve can "crush a little more" when you shock load the gears... that doesnt' really make sense, and in reality I don't think it makes a damn, as long as the pinion nut doesn't move. I've replaced junkyard 4.10s with no crush sleeve, just set the pinion bearing preload then tack weld the nut on the end of the pinion. All a crush sleeve is for is for building diffs at the factory. Slap it in and torque to a #.

CarolinaCrawler1 · Sep 5, 2017

TBItoy said:
solid pinion spacer, good bearings, LOTS of carrier bearing pre-load, touch deep on the drive side with minimal backlash.

What's considered minimal backlash? Do these recommendations also hold true with the 9.5" diff?

TBItoy · Sep 5, 2017

CarolinaCrawler1 said:
What's considered minimal backlash? Do these recommendations also hold true with the 9.5" diff?

.001 for an offroad only rig... Or even zero.

Backlash is for gear noise and heat expansion (gears aren't perfect, so they wont' have a perfect mating surface until broken in)