have a 1992 GMC Sonoma and the four wheel drives doesnt work?

[Jeff Martin]

I don't know where to start looking it has a four shift and when you put it in four wheel drive like four low the truck gears done like it should so don't think its the transfer case and ideas would be very helpful thanks

 

[davidm2232]

maybe the hubs aren't locking? look in the owner's manual to see how the 4x4 system works. you may have a live front axel so the hubs are always locked. it may be the transfer case as there is a mechanism to engage the front drive-shaft.

 

[dick car guy]

then it may be in one of the hubs in front, if one is not working it will not go into 4x4 this is a common problem any time I had a problem with the front hubs I put a set of warn locking hubs on front some years you can, some you cannot. But first figure out if one hub or the other is not locking.

 

[Molson02536]

I don't know where to start looking it has a four shift and when you put it in four wheel drive like four low the truck gears done like it should so don't think its the transfer case and ideas would be very helpful thanks

The front axle are locked with a vacuum actuator which is located under the battery box tray. Start with the simple and inspect the actuator, it's common to fail due to corrosion and the rubber diaphragm to break. The other thing also is to inspect your vacuum lines for your 4wd system, a crack and damaged vacuum line will not have any vacuum for the actuator to work and your front axle will not engage.

Start with these simple thing and if both are in working order, inspect the cable from the actuator to the front pumpkin where the cable is attached. There is a good chance that the clip has corroded off and the cable is moving freely and not engaging the front axle.

Keep us posted and good luck.