Where abouts is that rubber elbow?
Alot of the time it is the actuator located on the front diff. look under the front of the truck at the hog head if you look you will see wires going to the actuator it screws right in the hog head.If this is not the case you my have a vacuum line broke located under the battery there will be a square block under there,check the vacuum line first.
i have a 95 Chevy astro van.what would cause the all wheel drive to work sometimes but not all the time?
There are literally 100 different things that can cause your four-wheel-drive not to work. The most common cause is a disconnected wire on the four-wheel-drive selector switch.
A stuck/frozen e-brake cable could do that.
That would be the rear passenger tire.
2 wheel or 4 wheel drive would help.
Not usually, the four wheel drive is hooked up after the transmission. If you are having problems with your transfer case it will sound like the transmission because the transfer case is bolted to the back of the transmission. The four wheel drive operates independently from the transmission. If you have a bad transfer case that would cause locking in the drive line it could cause problems, but your vehicle is designed to use the four wheel drive and typical use of your four wheel drive won't cause damage to the transmission. It would be advisable to only use it as necessary because it will decrease your fuel economy by about 20%.
the transfer case motor has to be replaced
maybe its automatic transmission fluid
When you drive over a clicking bettle.
if it is front wheel drive then you need new drive axels
The transfer case could have been jammed, such as by shifting int 4WD while wheels were slipping. If a pin bends, it can stick the transfer case in 4WD permanently.
Anything is possible if you have the money, but it would be by far cheaper to just purchase a used 01 Silverado with 4 wheel drive and sell yours.