The dreaded 99 diff blown

[paflytyer]

I don't know that the 4-pinion is that much stronger. At least not in this case. OP says it's the ring gear, not the spider gears. Unless the spider gears blew chunks that took out the R&P.... My 4-pinion diff broke on an obstacle that wasn't out of this world..... But it was the R&P.

I went with a TJM Pro Locker and have been very happy with it. I don't think you can go wrong with ARB or TJM, but if you plan on going off pavement ever again, fix it right this time.

 

[AimCOtaco]

This has likely been discussed, but has anyone looked at installing one of the various LSD from the late 86.5 - 92 Supra?

An LSD in the front of an all-wheel drive? Never heard of that set up before. Is the late Supra the same diff/R&P?

 

[paflytyer]

An LSD in the front of an all-wheel drive? Never heard of that set up before. Is the late Supra the same diff/R&P?

Wouldn't this make something more likely to break? I don't think I'd want something that essentially "auto-locks" in the front of any vehicle.

 

[bjowett]

The R&P is different, but the diff carrier is the same. A LSD can be run up front in AWD systems, but the selection needs to be appropriate... not too aggressive. The 4 pin clutch pack LSD could work well here, it will reduce shock as some power will always be flowing to both wheels. One of the Torsen diffs could really work well with the A-trac, or it could shock things depending on how aggressive the A-trac needs to be to get the Torsen to activate when a wheel is in the air. Will either be better at preventing breakage than a full on ARB locker? I can't to say at this point. I had decent results with the clutch pack LSD in a high pinion 80 series front axle. My long winded ramblings here are to suggest a less expensive alternative might be readily available.

 

[REDrum]

An LSD in the front of an all-wheel drive? Never heard of that set up before.

Yup, no prob, been running them up front in Subies for over a decade (both plate and viscus).

I'm leaning towards a Kaiser in the front of my UZJ100. $850, drop in, no pumping. First need to take my buddies out in some snow and see how much, if any, understeer it invokes.

 

[Letsgomoreplaces]

Yes it will fit, we actually stock these units but I would strongly advise against an LSD in the front of an AWD, IFS vehicle. What I think is actually cool is you can put an ARB or TJM Locker in a 92 supra or IS300 etc LSD Unit IS300, Supra, Cressida, Crown

TJM Pro Lockers 100 series:
TJM Pro Locker Toyota Land Cruiser 100 Series IFS SPECIAL
TJM Pro Locker Toyota Land Cruiser 100 Series Rear

We also have several good used Take out Open diffs in 2 or 4 pinion. We actually have one on its way here 99 stock tires, got stuck in the snow and boom.
The front 100 series diffs break pretty easily for a few reasons:
-the 4.7 is very quiet and is difficult to realize the wheels are spinning rapidly
-IFS has less travel, allowing 1 wheel to leave the ground and loose traction more easily, then the spinning wheel gains traction and boom.
-OEM diffs are often setup from the factory with very little carrier bearing preload, which allows deflection and breakage of Ring & Pinion.
-OEM carrier, whether 2 or 4 pinion allows more deflection.

Spider gears break most often due to a rapidly spinning wheel which finally gets traction. And yes the 2 and 4 pinion both break fairly often.
Ring & Pinions break most often due to deflection or chunks from other parts like spider gears going through them.
An ARB or TJM Locker helps overcome these issues by offering stronger internals, in a much more rigid diff case which acts as a strong backbone for the Ring & pinion, and helps control deflection. Also, if you have the front end locked prior to doing a huge "1 wheel peal" it will be less likely to have a spinning wheel come back down and break things.

This has likely been discussed, but has anyone looked at installing one of the various LSD from the late 86.5 - 92 Supra?

 

[REDrum]

but I would strongly advise against an LSD in the front of an AWD, IFS vehicle.

Why?

 

[Letsgomoreplaces]

A traction device will have a much greater effect on handling in the front vs. rear. Example. If you drive an AWD LC with the rear locker locked in an average scenario, it drives pretty decent really, although barks rear tires on corners. Now take the same vehicle and lock the front locker while the rear is open and you hardly can steer. The LSD will have similar effect, but is not 100% locked. It will also put more added strain in terms of wear on CV's etc. I've driven EVERY imaginable combination in nearly any vehicle out there, and this is just not a good idea. That said I do like LSD units and they have there time and place, but not in the front of an AWD, IFS, LC. I've run them in part time 4wd's many times, while they drive ok on slick surfaces, they will limit your overall speed on snow/ice highway driving, and would be unnacceptable for daily driving. The front is the steering end, and there is much greater differentiation requirements as the arcs each wheel travel in a corner are even greater. In the rear an LSD or locker can give feedback when driving, but not to the steering wheel.

BTW REDrum, did you happen to see us in your neck of the woods a couple weeks ago? (Rio Bongo

Why?

 

[REDrum]

A traction device will have a much greater effect on handling in the front vs. rear. Example. If you drive an AWD LC with the rear locker locked in an average scenario, it drives pretty decent really, although barks rear tires on corners. Now take the same vehicle and lock the front locker while the rear is open and you hardly can steer. The LSD will have similar effect, but is not 100% locked. It will also put more added strain in terms of wear on CV's etc. I've driven EVERY imaginable combination in nearly any vehicle out there, and this is just not a good idea. That said I do like LSD units and they have there time and place, but not in the front of an AWD, IFS, LC. I've run them in part time 4wd's many times, while they drive ok on slick surfaces, they will limit your overall speed on snow/ice highway driving, and would be unnacceptable for daily driving. The front is the steering end, and there is much greater differentiation requirements as the arcs each wheel travel in a corner are even greater. In the rear an LSD or locker can give feedback when driving, but not to the steering wheel.

OMG....never mind.

 

[AimCOtaco]

Given the choice between a select-able locker and a "non-aggressive" LSD for off-road use I would choose the locker every time. Better control, better crawl with a tire in the air, total no brainier to me. Probably rare that the Subie is crawling rock with a tire in the air... apple != orange.

 

[Letsgomoreplaces]

And here is a 99 in our shop that would not have faired any better if it were 4 pinion oe.

 

[r2m]

I absolutely agree with Just Diff's about lunch box lockers on an LC. I did install them in a '89 Toy PU on both the front and rear. They worked great off road and were not too bad on road, but again, Toyota pickups aren't "All-Wheel-Drive" either.

 

[hoser]

I've driven EVERY imaginable combination in nearly any vehicle out there, and this is just not a good idea. That said I do like LSD units and they have there time and place, but not in the front of an AWD, IFS, LC.

Have you driven a stock Subaru STI? They have LSD front, LSD rear, AWD and IFS.

 

[montegofd3s]

Yes, but doesn't the STi have a clutch type center diff which allows for slippage, and everyone knows the weak point in the STi is the transmission.....somethings gotta give somewhere.

 

[REDrum]

Have you driven a stock Subaru STI? They have LSD front, LSD rear, AWD and IFS.

As do Mitsu Evo and Focus RS and Citroen Zara and every gravel and tarmac AWD rally car on the planet.

Yes, but doesn't the STi have a clutch type center diff which allows for slippage, and everyone knows the weak point in the STi is the transmission.....somethings gotta give somewhere.

Some have/had 20kg viscus most have electro clutch. Subie STI 6speed is a very rugged and proven Porsche design gearbox. A stock one will hold up to 600 Ft/lbs of wTq and requisite driveline shock all day. Far stronger than Mitsu's 6 speed. You may be thinking Subie 5 speed.

There is a huge difference, by design, between an LSD and fulling locking diff. The former being tarmac and dirt-able, the later strictly off road. There is no hard logic not to run an LSD on the street, its what they were designed for.

 

[Letsgomoreplaces]

REDrum, sounds like you should put an lsd unit in the front of your 100 series and see how you like it...

 

[montegofd3s]

As do Mitsu Evo and Focus RS and Citroen Zara and every gravel and tarmac AWD rally car on the planet.



Some have/had 20kg viscus most have electro clutch. Subie STI 6speed is a very rugged and proven Porsche design gearbox. A stock one will hold up to 600 Ft/lbs of wTq and requisite driveline shock all day. Far stronger than Mitsu's 6 speed. You may be thinking Subie 5 speed.

There is a huge difference, by design, between an LSD and fulling locking diff. The former being tarmac and dirt-able, the later strictly off road. There is no hard logic not to run an LSD on the street, its what they were designed for.

Very familiar with the differences. My H2 CRX has a KAAZ clutch type LSD in it. I will let you drive it around town and you let me know if it is very streetable. BTW my 05 STi granaded the transmission at eagles canyon with just an FPgreen upgrade.