View Full Version : How to disable 4WD
Envoy Fan
10-16-2005, 01:31 PM
How would one totally disable 4WD on the TB or Envoy. I would like to do some testing on the Envoy, and I don't want the 4WD to accidently kick in at any time or mode. A fuse removal or ?
Blulytes
10-16-2005, 04:21 PM
Don't you have a 2wd setting? That should prevent the 4wd from engaging at all... I know in this setting my tires will just sit there and spin away!
Envoy Fan
10-16-2005, 05:10 PM
Don't you have a 2wd setting? That should prevent the 4wd from engaging at all... I know in this setting my tires will just sit there and spin away!
Yes, but if I have it put on a dyno, I want to make sure it cannot in any way go into 4 wheel drive.
DouglasEsh
10-16-2005, 05:25 PM
Yes, but if I have it put on a dyno, I want to make sure it cannot in any way go into 4 wheel drive.
What would just disconnecting the switch from the back do? If it kicks it into 2WD you can be sure that they won't be able to acidentally put it into 4WD.
If it "accidently" goes in to the 4wd, either you got too close to the switch or there is a problem with your Trailblazer.
FattyTBEXT
10-16-2005, 09:58 PM
What would just disconnecting the switch from the back do? If it kicks it into 2WD you can be sure that they won't be able to acidentally put it into 4WD.
Not a bad idea. I had the switch unhooked from the back, but I didn't start it until I hooked the switch back up. :undecided
So you are saying there exists a possibility of engagement of 4WD. On a dyno I can see the concern!:eek:
For the peace of mind, I would spend ten minutes and remove the front drive shaft. I have not looked at it, but should be four bolts and your are good to go. That's what I would do. :m2:
blandmiller
10-17-2005, 03:10 PM
Bill, do the Envoy's come with the full-time 4WD like the Bravadas? I would be careful unhooking any driveline components before you investigate the PCM diagnostics and faults. The computer is pretty smart. It may have a problem if it is trying to engage the front axle and it sees that it is not turning. We spend 1/2 a day trying to disable a Hummer 4WD before we gave up. Try to locate a 4WD dyno and you will not have any problems.
One word of caution, do not apply your brakes at any time while you are on the dyno. Let the dyno operator stop your wheels whith the dyno brake. If you do, the computer will throw an ABS failure code and start doing strange things with the transmission. I told you the computer was smart......
ScarabEpic22
10-17-2005, 10:03 PM
Bill, do the Envoy's come with the full-time 4WD like the Bravadas?
No, the TB/Envoys are only available with 4WD, not AWD like the Bravadas. I think another GMT-360 uses the Bravada AWD system, but I dont know which other one it is. (P.S. The TB SS uses a different AWD system than the Bravada, it is beefier to handle the extra HP & TQ.)