1992 GMC Bound front end?

[Kyler Davis]

Hello, just looking for some advice on a issue i'm having. I bought a 1992 GMC k2500 from my neighbor for a song and have been rebuilding it. I am currently on the 4x4 and have come across an issue. When trying to engage the 4x4, the truck wont roll. At all. Wondering if anyone has any ideas on what it could be and how i can fix it, hopefully cheaply.

[green 788]

need more info... when you say it "won't roll" do you mean that the truck is running, and doing fine in 2WD, but when you put it in 4WD it acts like the brakes are locked?

 

...or do you mean that you've been pushing it from one place to another while you're working on it, with the transmission in neutral, and it rolls fine unless you put the floor shift in 4WD, then it's stuck (?)

[Kyler Davis]

Running and rolling under its own power in 2wd, but sticks when shifted to 4wd. It feels like the brakes are locked.

[Kyler Davis]

Got it to free up in 4wd, but am going to drain the front diff and hope it has fluid

[green 788]

check the universal joints from the transfer case, to both front axles. Drain and re-fill transfer case fluid as well.

 

this is a floor shift transfer case, right?

[green 788]

and one other thing... unless your front tires are *exactly* the same size as the rear tires, you'll get the same effect you're getting if if try to run the truck in 4WD on dry pavement. In fact, even with tire the same size it can feel like it's locking up the front end on dry road. I never use 4WD unless the terrain is somewhat slick or muddy, which will allow the tires to spin at their own revolution rate, and not work against each other. This honestly may be all that was wrong in the first place. :o

[Kyler Davis]

I appreciate the insight! This is my first GM truck, so i'm learning as I go.