4wd not working

[joedirt37]

sorry k5 guys,dont mean to put a dodge in here,my 1999 1 ton dually,i use to pull my buggy around all over colorado,the front 4wd want engage,the lever will go through all the gears,4hi,and so on.the 4wd light doesnt even come on now,it just spins the rear wheels,theres some vacuum lines goin to the pumpkin,looks like a modulator or something,are those d60's engaged by a vacuum source,thanks for the help

 

[andyblack]

Guess no one on here wants to talk about a dodge!

I had a '91 Dodge W250 with the same problem. I don't know if the later ones were the same or not. The vaccum motor on the top of the axle is a piece of junk! It has this shift fork thing that moves a sleeve that connects the axle shaft to this other piece...anyway it doesn't work after the truck is a couple of years old. You're going to have to get a conversion kit to swap it over to manual hubs.

With my truck, I reached in there and slipped that little sleeve into place and the front axle engaged until I put the transfer case back into 2wd. Then I guess the vacuum motor lost vacuum and the sleeve moved back.

I tested the motor my having my dad suck on it really hard, and it did engage, so I knew it was working. There was just so much slop in the shift fork and all, that I guess it wouldn't work anymore.

There is a company that makes cable lock conversions for the thermo-electric acuating devices on '88 and later GM trucks that may have a solution. It's called 4x4 Posi-Lock.

http://www.4x4posi-lok.com/app_dodge.html

 

[Hogback Fabrication]

If it works like the Jeep CAD's (and I bet it does) you can use a couple zip ties to hold the fork to one side so that it keeps the front axle shafts spinning all the time. No more failures, its just like having drive flanges in the front.