Question about 1986 GMC Jimmy

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1986 GMC Jimmy 4WD problem

1986 GMS Jimmy when put in 4WD doesn't go in and
when move truck get a clicking out of the front hub.
What could be causing this?

They are automatic locking hubs.

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Rich. There is a vacumn engagement of the front differential. The switch is on the transfer case. There will be a vacumn motor(looks like a curise control unit if you're familiar with them) under the hood with a cable running to the front diff. Make sure it functions when you engage 4wd. Probably does. If not, make sure it is getting vacumn by removing the line. It should **** on your finger when covered. If this all works properly, you could have trouble in the front diff. Don't forget the simple stuff, like CV joints, axle nuts tight, etc. You're driving an 86 so I assume you have a little experience in maintaince. Good luck. TJ

Posted on Oct 18, 2009


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