You will save truck loads of money by learning to do it yourself. That in turn will save your marriage lol. I've heard of so many horror stories about garages and ive personally witnessed some of the "mechanics" that work at these places. The only time my truck sees a shop is when its inspection time but my buddy does it and only takes a few mins.

 

So a co-worker ASE mechanic...said it may be the spider gears? 4 wheel works all the time going straight. Make a turn and the right front wheel lock up some of the time. Sound legit?

 

They also do the same thing when you turn left.

4 wheel doesn't work all the time going straight, unless you have full time 4wd. Aren't you driving around in 2 high? Yes, all the parts move, but they aren't connected through the transfer case.

I'm not saying it can't be the spider gears but stick with whats more likely. CV joints wear out. They turn at tight angles and are just greased. Open differentials, such as your front, seldom do. They are immersed in oil and have very few shock loads on them.

Check the CV joints.

 

CV joint is the most common issue with all this going on. For $50 and only an hour of work...just fix it and see what happens. It's most likely the cause.