Project traction

[Jowett Engineering]

Let's face it, the Tundra has an issue with getting the power down to the terra. It's really no surprise with the power it has stock, never mind the supercharger (which is really the catalyst for me to find something as I'll be installing te TRD SC in the coming weeks). As most know, traction devices for the rear differential are non existent. Calls have been made, and if we are very lucky something MIGHT come along in about a year... Too long for me.

Soooo, what to do? Well, Toyota has already solved it for us... maybe. The Tundra is based on the 200 series Land Cruiser which comes with an AWD/full time transfer case (the Sequoia also has a version). This 200 series case may bolt into the Tundra with minor complications... GAME ON! I have a unit on the way.

Hmmmm, 500 hp and AWD going through a lockable Torsen center differential with 40/60 front to rear torque split...

Additionally, maneuvering this beast in tight places while in 4WD will be easier. For instance, while plowing the truck frequenty runs on and off previously cleared or dry pavement, this causes wind up and the inevitable bind/ tire dragging and larger turning radius.

Thoughts good and bad welcome....

[Austin Aggie]

My thoughts are - I hope that it works! I'm optomistic. It would seemingly be a fairly easy switch. Is the overall width of that third member the same as the Tundra (either the Sequoia or Land Rover)? I'm full-on tuned into this.

[jgonzales]

I'll be following this one too... count me in as interested.

[thumbster]

I'm curious how the front diff comes into the equation - the ECM might be pissed off about not having full control of the transfer case.

[Jowett Engineering]

The width of the 200 and Tundra diffs should be the same. Though that may not matter as the stock front differential could potentially be retained by locking the ADD sleeve.

Right now it appears as though the the electronic shift actuator on the 200 series case will plug right into the Tundra harness and possibly use the Tundra 4WD ecu. The actuator on both vehicles work in nearly identicle ways... the difference lies in what the first function does, on the Tundra it shifts the case from 2WD to 4WD, on the 200 it locks the center diff. A quick run through the manuals for both vehicles shows the same wires and signals are used to show 4WD in the Tundra and center diff lock in the 200. Basically the stock t-case switch on the dash would work like this 2WD = AWD, 4HI = center diff lock (with resulting light on the dash), and 4LO = 4LO.

The significant problems I see right now are what to do with the front ADD actuator and the resulting signals it sends to the ECU.... and what will the truck's traction control and stability systems do when power is flowing up front and potentially causing wheel spin when it thinks it is in RWD?

[RONE]

Wow, good luck! That would make for a very impressive beast.

[Jowett Engineering]

The case has arrived. It dosn't look a whole lot different on the outside, the only noteworthy change is a large grouping of cooling fins cast into the front side and bottom of the case.


Front diff... no differential disconnect.


Inside things are quite different. The center Torsen Differential is a T3 3rd generation piece. It is rear drive axle biased and can supply up to 70% of the torque to rear wheels... that means less understeer.

Center Torsen differential, Torsen is now owned by Toyota.

[rangerbrown]

looking forward to how this will turn out.

[THUNDERA]

I would *LOVE* to have AWD in this truck I wonder how it would effect power and fuel economy...

[Jowett Engineering]

Toyota rates the Land Cruiser at 13/18. Power... it will probably feel the same or better in many instances.

[OTR]

Will this decrease towing abilities for any reason???

[Jowett Engineering]

There should be no reduction in towing abilities... if anything ability would be better due to the traction and handling benefits of AWD.

[VX_R-V8]

Not to be negative in anyway, i believe this is a great idea once you've got it on and going. However, i do believe that you will encounter another problem in addition to the ones you have mentioned; Tundra has an excellent turning radius (best in class i believe), and you should be sacrificing that due to awd... Hope it works out for you though.. goodluck n keep us updated

[TundraBay]

Leaving rear axle as is for the time being?

And all this can be had for a mere what - - 10 G?

[Jowett Engineering]

The center differential should prevent any increase in turning radius. Additionally it will allow traction on surfaces like grass while minimizing tire impacts to it that regular 4WD wind up would cause while dragging a tire.