Ok...I decided to put my 4.7L D in 4WD for the first time this winter. Didn't really need to, but the intersection was a little icy and didn't want to sit there and spend my wheels if I didn't need to. I put it in 4WD High but it didn't feel like it engaged all the way. It was real jumpy and seemed to me like it was engaging and disengaging about every second or so. Am I looking at a new transmission? I just hit 100K and was afraid of that. Any ideas?

 

i think you are probably fine, nothing wrong, im assuming you mean it was jumping and not wanting to turn through the intersection. This means that your 4wd is working as intended, the four wheel drive system locks the front an rear driveshafts together. when you turn this causes problems if you are on dry (or mostly dry) pavement as the front and rear wheels (and therefore the driveshafts) want to turn at different speeds, but having the 4wd engaged doesnt aallow them to turn at different speeds, thus generating axle bind as you go around corners. in order to relieve the axle bind the wheels hop/jump across the pavement which is what you have been feeling the "engaging disengaging every second), when you are driving forward in a straight line you shouldnt feel any difference in the way the truck handles unless you hit a low/no traction situation.

so to sum it up in case you dont feel like reading all of that, your four wheel drive is working as it is intended but you tried to use it in a situtaion where it wasnt needed creating axle bind and therefore wheelhop which is wha tyou ahve been feeling

 

I hope it was something simple. I wasn't turning I just kept going straight. Also, I have never had it act like this before. It has probably been about a year since it was ever put in 4WD because I had been in Afghanistan for awhile. Thought it seemed wierd because I had never had problems with it before.

 

Well I don't see a problem either. Besides, if your transmission is going out it will not affect the Transfer Case as they are mated but 2 different parts.

 

OK...I'll give it another shot tomorrow and see how it works. If I have any problems, I'll post them.