1990 Chevy 4x4 4wheel fails to engage?

(2011-02-03 15:20:39) 1. Pit Bull Says: Today was a very snowy day and this morning i woke i started the truck and waited till she was warm and then engaged 4hi, when leaving work today I noticed it took several second before the indicator light comes on. Note i have a floor shifter not a push button. This evening I did the routine started the truck waited till warm and shifted into 4hi but now 4wheel will not engage, neither 4hi or 4lo did the reverse and drive but not to any success, I went to the store and was there while it was running for about 15minutes, another attempt 4wheel will not engage.. and Ideas to what I need to look for, or is there a possibility something is frozen? any advice would be great.2. MasTec 1970 Says: This is a common thing to go wrong in the k series chevy of this vintage! The problem is most likely the front axle actuator, It is a crappy design with a heater that heats a wax pellet bladder inside to expand and move the fork to lock the axle! GM and a few aftermarket manufacturers make an improved design that is far more reliable. To replace the actuator simply locate it on the front axle (It looks like a round cylinder with a electrical connector) Disconnect the connector,get a pair of channel locks or large crescent wrench and unscrew it. Reverse to install! Hope this helps.3. landon Says: what is wrong is on your front axle it is the 4x4 shift solenoid it is what puts the Chevy's front end in like hubs common problem EASY fix just unplug it spin it off and replace with a new one good luck Tag: 1990 Chevy 4x4 4wheel fails to engage?