96 k1500 4x4 question

[deh1]

My 96 k1500 has push button 4 wheel. when you push either 4 hi or 4 low it shifts into 4 wheel but then shifts back out only a second later. you can hear the relays clicking in and out under the dash, you can hear the transfer case engage aswell. I havent been able to check for voltge at the front actuator because it shifts in and back out to quick for me to check by myself, although I only changed it a year ago.
Any ideas would be much appreciated.

[MT-2500]

Originally Posted by deh1

My 96 k1500 has push button 4 wheel. when you push either 4 hi or 4 low it shifts into 4 wheel but then shifts back out only a second later. you can hear the relays clicking in and out under the dash, you can hear the transfer case engage aswell. I havent been able to check for voltge at the front actuator because it shifts in and back out to quick for me to check by myself, although I only changed it a year ago.
Any ideas would be much appreciated.

What transfer case?
Auto matic 4W or 3 button reg shift transfer case?
If old 233/243 - 3 button you can ground pin 13 on diagnostic connector and read codes on shift button lights.
Post back codes.

[deh1]

Thanks for the reply.
It is the 3 button 243 transfer case. I tried grounding out pin 13, as soon as it is grounded the light on the 2 hi button goes out and does not flash any codes. Just to be sure pin 13 is 3rd from the right on the bottom, correct?

[MT-2500]

http://www.troublecodes.net/OBD2/

[MT-2500]

With pin 13 grounded key off turn key on and it should flash codes of 1-4.

If no codes next step would be to get a repair flow chart on it and go threw the repair flow chart.

Good luck

[deh1]

Okay so I have checked for codes a few times now and dont get any. After checking for damaged or loose wires I could not find anything out of the ordinary. after repeatedly pressing 4 hi it suddenly locked in and i can switch from 4 hi to 4 lo BUT NOW IT WONT GO BACK INTO 2 HI. when you press 2 hi the light blinks twice , you can hear the shift motor moving but it goes back to 4 hi. Maybe this narrows it down to a weak shift motor?

[tblake]

I had mine stick in 4x4 low one time leaving the lake. I didn't know what to do and didn't want to drive it very far with it in Low.

I backed up while pushing 4x2 and it popped out of 4x4 low. I am not sure why it did it, but it has been fine ever since. Locks in and out normally now.

[deh1]

Well after further troubleshooting I found that the encoder motor did not have enough torque to fully shift the transfer case. I changed the motor only to find the new one did not either. When I had the encoder off i could shift the transfer case with a wrench but it took alot of force to do it so im thinking that their is something wrong inside the transfer case and that I need a rebuild. Crap!

[777stickman]

Originally Posted by deh1

Well after further troubleshooting I found that the encoder motor did not have enough torque to fully shift the transfer case. I changed the motor only to find the new one did not either. When I had the encoder off i could shift the transfer case with a wrench but it took alot of force to do it so im thinking that their is something wrong inside the transfer case and that I need a rebuild. Crap!

You may want to drain the t-case and refill with GM Auto-Trak ll P/N 12378508 fluid and see what happens. It's not cheap stuff but it could save you a rebuild if it works. When you drain it try to use a coffee or paint filter to catch any thing unusual that comes out.