'95 Tahoe 4wd problem

[MattBlackXJ]

The 4wd quite working on my Tahoe, I know the problem is in the front diff, it isn't engauging. It looks to have an electronic actuator, but I can't tell any more then that without removing the diff and opening it up. I'd appriciate any advice, or if you can reccomend a good Chevy truck tech forum.

 

[Lawn Cher']

It is a thermal actuator, and (mis)behaves just like the vacuum actuator on early Command-trak D30's. The simplest (and probably most cost-effective) route would be one of those cable-actuated posi-lok gizmos. Then you get 2-low!

Knock on wood, it still works on my Suburban.

 

[Matthew Currie]

Those thermal actuators are pretty notorious. However, before giving up on it, make sure that all connectors down below are free of corrosion, etc. I think there's a plug at both the actuator and the TC end of the harness. Also make sure that your shift linkage is moving freely all the way. My 88 Chevy has a perennial problem that the shaft that goes through the floor to the linkage seizes up in its bushing, and gets very stiff. Eventually, it won't travel far enough to hit the switch for the actuator reliably, even when it seems to have shifted. Every year or so I have to flood it with oil, and go through the shift sequence about a hundred times, until it frees up.

 

[Lawn Cher']

Found this today, might be of some help.

http://www.pirate4x4.com/forum/showthread.php?t=297980

 

[MattBlackXJ]

Thanks Mark. I'll probably go posi-lock. I took a good look at the shift linkage and electrical already to eliminate the obvious stuff.