broken 4 wheel drive

I have a 95 chevy 1500 and i broke the 4wheel drive offroading.  The shifter is on the floor and it shifts back to were its supose to be in 4 wheel but it dosent go into 4wheel.  I have talked to other people about it and they say it is either the vacume or the transfer case.  I was wondering what the problem might be and how much $ it will be to fixed.  

There are several things that may prevent 4wheel from engaging in you truck.

First off, if you put it in 4Low, do your rear tires still turn in low range? or is there nothing there? If you can get Lo range, your T-case is still good, If not, you likely need a new t-case or a rebuild.

If you get Low range but no front axle engagement, the problem is likely the electronically controlled engengement of the front pinion. Depending on the year of your truck, it is either an electromagnet or a heating coil the engages the front axle right in the front diff housing. This system is crap, mine doesnt work in the cold. Summit Racing sells a manual cable actuated system to eliminate this.

Good Luck

P.S. If your Tcase seems toast, take it to a mister transmission and see what hey think, they do no cost assessments. If they say it is toast, remove it yourself and take it to them to have it rebuilt, you may be suprised at the low cost of a rebuild when they dont have your truck wasting thier shop space on the hoist for two days!