Need some help,

I have a 97 Gmc Serria Z-71, recently this last weekand my wife and I took a nice trip to the beach, well I went to go and drive on the beach, which you can here, and I think I am in 4 wheel drive, and guess what. I hit the soft sand and I stop moving and my rear end sinks. It took 3 tries to have someone pull me out. Anyways, my question is, I have auto locking hubs, and when I put the truck into 4 wheel, I could hear the gears, but the front wheels wouldnt lock. I have been told that I can convert my auto lock to a manual, I have heard of ox lockers, anything good. Or should I take my truck in and get that damn auto lock fixed, any assistance on what the problem could be or what I could do to fix it that wouldnt be to high in price. Without 4x4 my trucks value has shot down, and I would love to get it fixed so that I dont have to lug the huge cooler of beer halfway down the beach, THanks anyone.

mike

It's probably your thermal actuator. A common problem in '88 and up Chevy/GMC. It won't fully engage the splined collar on the axle shaft, or doesn't work at all.  Check out 4X4 Posi-lok...

http://www.4x4posi-lok.com/chevy_page.html

It should fix your problem. Easy to install, cost about $170, plus it allows for 2WD lo, if you need it.

Now you won't have to lug that big cooler o' beer by hand.

Good luck.

sounds like it probably is your thermal actuator.  But if you replace it from chev.  get the new electric one.  It works much better.  I also have a 97 GMC Z-71 that spends alot of time wheeling in the mud and towing off road.  When my actuator went out I installed one of the electric ones and havn't had any trouble w/ it since.

I just had the same prob on my 90 f-150 a couple days ago... sometimes the auto hubs will get a lil too much grease in there.. and it causes them not to lock in...  i pulled mine out, wipped the grease off, put a small amount of grease back on them, just enough to make them slick, but not enough to make it like glue,, and put them back together,,  not sure if thats whats wrong, but thats what happened with mine and i had similar symptoms,, cheap and easy fix... just rememeber to go one side at a time...  

Auto-hubs dont apply to 88-98 GM trucks. It is a central axle disconnect system.

I thought my thermal actuator was toast in my 92 k1500 last weekend, but it turned out to be moisture in the "weather-pak" connector about 2 feet up from the thermal actuator housing. Dried it out, its fine now.

Posi-lok is the way to go. For $150 you'll never have front axle actuation problems again. (plus you get 2Lo for backing up heavy loads).

Good luck.