Rear Differential Problem

[RockstarCondoms]

I have a 2000 4Runner SR5 Sport (hood scoop opened), 5-speed manual transmission with TRD supercharger, TRD supercharger belt tensioner, TRD cat-back exhaust, TRD air filter (air box opened), and TRD brake pads. I have Toyo Proxes S/T tires (+ 1 size) on 16" five spoke OEM rims.

I have over 325 hp and over 350 ft

 

[OUTRNNR]

Of course TRD is going to disagree with you so they don't have to foot the bill. If you are really running the numbers you say I'd say you are simply overloading the system and the rear diff seems to be the weak point. Apparently you have exploited the weaknesses in the Toyota rear ends at least for your year and model. Although they are fine for stock power applications, Toyota rear ends (or any stock rear end for that matter) just aren't built for a 50% increase in torque.

I have a friend who dropped a Chevy 350 into his old Land Cruiser and threw 33's on there. When we were up on a trail he snapped the pinion gear into little pieces. Not saying this is comparable to your situation, he probably double or tripled the torque that the diff was designed to handle, but it was the weak point.

Sounds to me like you are going to need to upgrade that rear end. I'd talk to the 3rd gen guys to get some good advice

 

[Expat]

Is that a 911 turbo I see in the background? (Me a Porsche enthusiast).

Can't your master tech guy recommend a solution?

I'd check with the rockcrawling crowd. They break plenty of stuff so they may know whats tough enough to stand up to your torque numbers.

Don't know if the pre-runner (desert racer) guys do rear end mods too?

 

[Koz]

I have a 98 PreRunner with the TRD blower with about 90K miles and BEAT THE PISS OUT OF IT since new, with no problems at all. I've run it several times at English Town Raceway (Drag Racing) and light the tires on a regular basis, again no problems at all. I do have the TRD off-road 4:10 locking rear.

Koz

 

[LT5]

The 8" rear axle in your 4Runner is quite stout. It is same basic differential assembly as the 4th Gen 4Runner.

I have seen many survive V8's with twin transfer case setups and 35+ tires.

Verify with your tech that you indeed have the "V6" 4 pinion case installed. I have read and heard, what should be installed is not always the situation.

Ask what parts are failing. Pinion bearings, carrier bearings, ring & pinion gears or parts within the differential case. That would make a difference in your solution. If the case or parts within are failing then you could move to a stronger case.. ARB or Detroit. Gears, then stronger aftermarkets are available.If the bearings are failing ,try a premium synthetic oil. Perhaps the preload setup needs tweaking.

Check out the Toyota 4X4 vendors that sell complete third members or a shop that specializes in gear setups.

Visit the Pirate4x4 site. Many knowledgeable " gear " folks over there.

Everything has a breaking point and if it becomes a problem then there is an easy solution. Spend money. Ford 9" or Dana 60 custom rear comes to mind.