Originally Posted by duramaxthis
put in 4x4 get on tar and crank all the way to the left or right, if it hops and tires chirp, it works if not it dont
Hold on, do you want someone to break there truck. Come on this is the worse idea I have ever heard.
Not only can you break the hubs, u-joints, axle shafts, t-case. You can cause damage to the transmission casing.
To properly test your 4wheeldrive. First off you want to inspect everything. Take the hubs off the truck, check out the seal for the vaccuum on the hub. Check the vaccuum hoses going to the hubs. Check the vaccuum pump. If you have electronic shift on the fly. Check to make sure your getting voltage to the motor. Make sure the motor is actually shifting into 4hi.
If everything checks out from your inspection. Then go find a dirt road. Put your truck in 4hi. Then hammer down the throttle. If it spins from the rear, your truck is not in 4wd. So stop put the truck in park. Manually lock the hubs in. Then hammer down and try again. If you are still spinning and not taking off. Your t-case is not shifting into 4wd or you have a problem in the T-case.
But what ever you do. Do not drive in 4wd on dry pavement.