91 Silverado 4wd actuator/thermal plunger

Just how hard is this to replace? I have been dealing with the slow engagement blues for a couple years, but it always eventually hooked up. I used a few times this summer for pulling trees down (okay guiding trees down, not actually yanking them out of the dirt) and had no problems.

Now, I get not lights, no front end engagement and white knuckles on the way to work. What do I need to check to make sure the actuator is bad? The 4WD fuse is good. How hard is this to replace? I know GM came out with an electro-mechanical actuator as and upgrade, are there any other options? Manual hub conversion?

Reply to
Dirty White Boy
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No way to do a manual hub conversion without changing out the entire front end and suspension. The actuator is VERY easy to replace. One wire connection and the actuator itself just unscrews from the top side of the axle housing. Might take you 30 minutes if you drop the wrench 10 times and drink a beer after every step. Install a new thermal unit OR use the motor driven one, just make sure you get the conversion wiring and the extender that you need for it to work.

Reply to
Steve W.

Thanks Steve. Looks like I'll have to not drink and dig out those magnetic gloves! Wish I had a garage... Time to call a friend with one.

Reply to
Dirty White Boy

After 8 calls, finally found one in town ($92 @ NAPA.) Installed in 10 minutes tops and I DID drop the wrench a few times. Keep in mind cold, snow, ice and NO garage. Working like a champ now. Of course, I wasn't drinking...

Thanks for the help Steve!

Reply to
Dirty White Boy

Make sure the 3 vac lines that go to the switch on the tcase are in good order and are connected. Will it go into 4LOW? If so, your encoder motor works so it's likely a vac issue (could also be the module or the solenoid). I think that you will have to either look under the batt tray for it or follow the vac hose closest to the firewall and apply vac to it to see if it locks the front end.

Good luck. I just went through all the same stuff - it's madness. The problem ends up being that the system itself is flawed by logic issues on the board so it never really works 100% in my experience. Look for my last post answered by Steve - he put up a great pic online explaining locations of vac hoses, etc. Thanks. Andrew.

Reply to
AWN

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