Kerr

Guys i need help..

I have a 01 2500 burb with the auto, 2wd, 4hi, and 4lo trasfercase...

When i push the button it shift to the correct setting but i dont always get power to the front wheels when needed.

Last night a tree fell across the driveway. I tried to pull it to one side so we could get home. In 4 hi and 4 low the truck works, you can hear and feel the tries gripping.. But when you apply power to it in 4ed nothing happens... the front tires dont do crap.. This has happend to many a few times in the snow, twice in the mud then again yesterday... Its like the T case is slipping under a load...

So any way to fix this or replace it with a regular 2wd, 4hi 4low case..

TieRod

It might be the actuator in the front differential is bad.

Neil 6.0

I'll bet the transfer case is toast, the clutches anyway. You will know for sure if the t-case fluid is black. For some reason those 2500 autotrac cases aren't worth a crap. If you plan on keeping the burb for a while, I'd definitely consider a floor-shift replacement or maybe even a pushbutton non-autotrac t-case out of a 2500HD 6.0/4L80E truck. There will be some programming issues to deal with and you might have to change the axle actuator out, can't remember if they engage differently.

Kerr

thanks guys.... i guess im going to start with the encoder moter? they said it send a signal to slide something in the trasfer case... if it goes bad it will not lock in all the way.

Ive never even used that auto 4hi so doing a swap to a naormal one would be fine with me.. also the dealer told me there are no clutches in these, its driver off a plantiary gear set?


Tierod... any new stuff of the turbo truck.

Neil 6.0

Encoder motor is a possibility...but the dealer is wrong about no clutches.

http://www.chevyavalanchefanclub.com...opic=41895.new

"During normal driving situations, the transfer case can operate in the Auto
4WD mode. In the Auto 4WD mode, the transfer case shift control module
monitors rear wheel slip speed, based on the inputs from both the front and
rear propshaft speed sensors. When the vehicle experiences a rear wheel slip
condition, the transfer case shift control module sends a pulse width
modulated (PWM) signal to an electronic motor, which is the transfer case
encoder motor. This motor rotates the transfer case control actuator lever
shaft, applying a clutch pack. This clutch pack is designed to deliver a
variable amount of torque, normally delivered to the rear wheels, and
transfers it to the front wheels. Torque is ramped up to the front wheels
until the front propshaft speed sensor matches that of the rear propshaft
speed sensor. Torque is ramped down to the front wheels. The process would
repeat if rear wheel slip is detected again."

Hope the encoder fixes it.

Kerr

Neal you are correct... we did the encoder motor last night...

All wheels turn on the lift but if you apply the brake the front wheels and drive shaft stop and the rear wheels keep turning. same goes if you give it gas and brake..

Do you know anything swaping to a regular t case.. out 04 2500 has 2WD 4Hi and 4Lo...

if i killed the clutches with a stock 8.1 im sure they will not live long with the cam, headwork, and whipple on top.