difficulty disengaging 4hi lock

[HummBebe]

Originally Posted by marin8703

have any of you had difficulty comming out of 4hi lock? it happens to me every time. when I press the button to go from 4hi to 4hi lock, no problem. Then when i press the 4hi button to go from 4hi lock to 4hi, the light moves to the correct button, and i hear a click from under the car. I assume at this point its supposed to have unlocked.

However when i try to make a turn, it gets all difficult to turn and the truck actually stops. Im assuming this is the axles binding from the turn. It will do this for a while, and after clicking between 4hi and 4hi lock several times and going backwards and forwards several times, they will stop binding at some random time, and everything is fine.

Is that how its supposed to happen? Isnt the transition supposed to be instant?

oh and by the way what happens if you force a turn when the front and back are locked ( I didnt force it, just curious), by increasing the throtle/power, is something gona snap or are the wheels gona slip and sync up?

Thanks!

Take it to the dealer....

I will assume you are in neutral when you are making the transition fro 4hi to 4hi lock?

It does in my eperience take a couple of seconds for it to feel freed up after switching, but what you are describing almost sounds like a t-case issue.

[Sewie]

Originally Posted by HummBebe

I will assume you are in neutral when you are making the transition fro 4hi to 4hi lock?

You don't need to be in neutral to switch between 4hi and 4hi-lock.

Mine sometimes takes a minute to switch but I've never had the problems you're describing. BTW, the front and rear don't lock when you put it in 4HL, its the center. And even on pavement, being in 4HL shouldn't cause what you're describing. Get it to the dealer.

[f5fstop]

As a person who was checking out his new transfer case this morning, I have to agree with most. And, it works as my older case did (just not as noisy when braking ).
If you switch from 4lo lock to 4 hi normal, when sitting still and in neutral, it will take a few seconds to be totally unlocked (as Bebe stated). However, disengaging while in neutral and rolling at about 2 mph, it should unlock faster.
This is normal under most conditions and is primarily due to the teeth in the input shaft meshing with the planetary gears. If you are slightly moving, the gears unmesh quicker, if not moving they are meshed together and take a few feet to unmesh. That is one of the clunks you here when engaging.
If they do not disengage, it is usually due to the encoder motor, and you can remove the motor and manually turn the shift cam that the motor is turning.
If the motor is not the fault, you got t/case problems.
Early models did have some TCCM and encoder motor problems, but thanks to BW and GM engineering, these problems have been reduced notably. Not saying one could not break, but chances have been cut significantly.

YOU WILL get the binding of the front wheels if driving on pavement in 4lo or hi lock, even with an open front diff, until the case totally unlocks from 4lo lock. From the owner's manual:
Notice: Driving on pavement in Four-Wheel
High Lock or Four Wheel Low Lock for extended
periods may cause premature wear on your vehicle’s
powertrain and tires. Do not drive in Four-Wheel
High Lock or Four-Wheel Low Lock on pavement for
extended periods.

You also have to be in neutral (or have the clutch engaged) to shift into or out of 4 lo lock. The preferred way is to be moving less than 3 miles per hour, but in neutral. If not in neutral, the TCCM will not (or better not allow) a shift into 4lo lock. You should also remain in neutral until the 4lo lock light stops flashing. I know on mine, if you push the lo lock button, the light flashes and nothing happens.

[HummBebe]

Originally Quoted by Stupid:
You don't need to be in neutral to switch between 4hi and 4hi-lock.

[marin8703]

thanks for all the responses everyone .

To adress some of the comments:

When switching i am in neutral, and rite when i hit the button maybe 3 seconds after i hear a clunk (metal on metal, down from the transfer case, i always assumed this was the disengaging process).

The buttons do not stick, made sure to check that, and the light does move over to the right button.

After switching in neutral and then moving forward slowly does not seem to hurry up the process. I have to try switching and then moving while still on the dirt road to see if that works faster.

I dont go offroad often, today was just a quicky for me, so this wont be a problem till next time i go to my dealer. I just wanted to see if any of you have had this issue, if it is an issue at all, before i go and make an idiot outa myself at the dealer.

Tomorow i will check how long it will take it do disengage without moving back and forth or pressin the buttons. Ill just move straight forward at about 2 mph as someone said. Ill also try on dirt road, or slipery road.

next time at dealer ill ask them to take a look.

Once again thanks for all the quick responses everyone!