AWD Reprogramming?

[PJC]

All,

Let me start this by admitting my gross lack of experience and just middlin' brains. Having said that, I tend to a whimsical imagination. So here goes:

We all know the differences between AWD and selectable 4WD. Since I am stuck with a GM AWD that lacks the human control of lockable Front-Rear Diffs and selectable 2-4 Hi and Lo; I am left to imagineering a computer reprogram of the AWD system I have inherited; vice re-fitting the drive system. Seems possible to send 100% power to front or rear by over-ruling the on-board chip(s) electronically.

Can this be done? Are there any commercial products to do so? Anybody tried it?

Any thoughts?



Crazy Paul

 

[gmcpimpin]

What type of vehicle?

 

[PJC]

2002 Escalade EXT AWD...or anything with computer-controlled AWD...


Paul

 

[shortbus4x4]

I have never heard of any aftermarket product to do that. To do it yourself and to do it right would be a monumental undertaking.

 

[Cody1771]

are you a computer programmer? in theory it should be doable, after all it is a program. has it been done before? likely not.

 

[AirForceOne]

It would easier to swap the AWD transfer case for an autotrac unit. It is close to a direct swap.

 

[shortbus4x4]

It would easier to swap the AWD transfer case for an autotrac unit. It is close to a direct swap.

This might work for an 02. I swapped a two speed case into a 00 Astrovan, took a bit of work for the speed sensors to work and the AWD light is on all the time now.

 

[1stDeuce]

PJC: To answer your question shortly: NO. The AWD t-case in your Escalade is not computer controlled at all. It's a viscous coupling t-case. I think there's a torque split differential in there too, so that there's a 40/60 split Front/Rear, and the viscous coupling serves to limit the differential action to a low speed delta, so that the front and rear will spin at relatively the same speed, probably up to a torque limit on the front. (So you can get 100% ish to the rear, but likely only 75% or so to the front.

On modern computer controlled t-cases (the ones with "auto" setting), it's not so much about controlling torque as speed... The rear is constantly driven, and the front is clutch engaged. The clutch can engage firm enough to force them to the same speed, which technically means you could put 100% torque to the front if the clutch will transmit that much torque, but only if the rear tires don't have traction. Otherwise, the directly driven rears handle whatever torque they can and the fronts get the rest, so to speak... If you think about turning, the t-case is driving the rear wheels, and the front ones have to spin slightly faster (bigger arc that they follow) which means for a "auto" t-case to send power to the front wheels in a turn, the rears must slip. This is the major downfall of an "auto" t-case in a RWD platform. It works much better in FWD platforms, where the fronts pull all the time and the rears can get clutched power but not quite have to spin as fast... More stable. Oops, I'm off course.

Sorry about your luck, but there's nothing you can do with your stock Escalade T-case. You can swap it for a normal t-case from a 1500 though.
Chris

 

[IdaSHO]

As far as non-electronic AWD, a viscous coupling t-case is the best you can get IMO.

Simple and reliable, with no BS. It is in fact a "full time 4wd" system. But just like any 4x4 with open diffs, if you lift ONE tire, you will find yourself with traction problems, as most if not all the available power will go to that one lifted tire. Spin, Spin.

If you are having traction problems I wouldnt point you towards a t-case upgrade.
Instead, start looking for a traction aide in the form of a selectable rear locker.

 

[PJC]

Chris

Many thanks for that Basic Training....

and IdaSHO,

so an ARB air locker can be an option for the rear?


Thanks to all for the comments, this is a great site

Paul

 

[1stDeuce]

Before you get excited about adding a selectable rear, check your glovebox for G80 code. If it's there, you should have GM's automatic locker, which works really sweet if not broken. You're still missing low range, but if you don't need low, and your truck isn't G80 equipped, a rear locker will indeed do wonders for mobility!
C

 

[86cj]

Or

"Works really sweet until it eventually breaks"


They don't call the Gov-bombs for nothing

The average SUV owner should not worry about having a Bomb in the rear axle. I have two GM Gov Locks, a 1998' 10.5" and 2000 8.5" both have worked fine since new.

Admittedly the Gov-Lock would be low on my list if I bought a new locker for off-road...."If you have a bumper sticker that says watch this.....". You will be able to break the Gov Lock.