Has anyone had a problem with the 4 wheel drive not unlocking.

We have one w/less than 1,000 miles that the dealer has not been able to resolve the problem. The event occurs when 4 WL or 4WH is selected. Then to disengage, the dial is turned to 2 WH, the light goes out, but the lock-up remains.

All tricks have been tried, nuetral transmission, back-up, throttle blip, to no avail. Then without ryme or reason it goes from low to high 4 wheel drive, then maybe 2 wheel high ?

Tire pressures are at spec.....My opinion has a rear to front axle ratio imbalance, transfer case ratio imbalance, weak shift solenoid or electrical circuit problem.

Older 4x4 designs had similar problems that were usually tire pressure/circumfrance related. The user solution was to back the vehicle up until the wrap up nuetralized, thereby allowing the shift to be made.

Try another dealer or carry it to the same dealer that cant fix it and invoke the lemon law. 1,000 on a vehicle shouldnt be causing headaches already. Is no code showing up or no check light?

It sounds like the 4x4 actuator that engages the front transfer case has gone south. It's just a solenoid and an actuator I believe. It's about a $150 part.

That vehicle should be under warranty, find another dealer.

Wannabe

GM is thought to have started a case file. Meanwile, I am anticipating the response and possible proposed options.

The Denali is a beutiful unit, but as with most Engineering, perhaps there is always a better solution. Anticipation includes options, such as Lemon Law, Finding the problem, supported by maximum extended warrantee or trade for a current like for like model.

Perhaps you guys can add insight by comparing the 2011 to 2012 or 2013 ? Such as improvements or complications after the 2011.

Thanks for your suggestions !

How is the Chris Cat running ?

Running great, had Tyler Crockett put new heads, roller cams on them. Old heads were shot.

Wannabe

Do you have auto on the switch? if so then the front drive shaft always turns even if its in 2wd..every one with auto 4x4 that i have seen has a locked front drive shaft...now if you dont have auto 4x4 and the front drive shaft is locked then maybe they installed the wrong transfercase from the factory which will also result in a wireing issue between the encoder motors that lock it into FWD..

My 08 did the same thing, I had to turn the truck off let it set a few mins and then tried it again and it came out of 4x4.. Took it to the dealer and they did a software update on it and no problems since.

Thanks guys, for your suggestions.

The report includes:

1) Code change, new code installed.

2) Possibly a sticking rear axle brake puck or caliper, holding a load on the posi-traction, then effectively inducing drive line wrap up.

3) A intermittant switch or electrical circuit.

Interestingly, there is said to be a service bulletin for shim changing the transfer case angle. However, the shim is said to effect ride quality.

This vehicle has +/- 3,500 # on the 5th wheel ball, when pulling the Motion and +/- 1,000# when pulling the pontoon boat. In doing the math, the 1,000# over hung load on the bumper hitch opproachs the 3,500# 5th wheel lever arm.

Point being, the problem occurs when either boat is pulled. (The Skater has not been pulled with this pick-up)

Either boat puts the springs on or near the overload springs and certainly changes drive line/axle angles. The shim solution was first introduced for heavy oil field hot shotters. The Tech explained, without the shim solution, after 4 WD low, the shift may require manuevering not explained in the owners manual. The Tech went on to say, the code change did reduce owner complaints.

Does any one have suggestions for obtaining an extended warrantee for at least a discounted price ?

Automotive News printed an interview with Mark Ruess, CEO, GM about customer satisfaction/retention. When I requested a complimentary extended warrantee, because of the created paper trail, unknown damage and effected residual value, it was denied.