any experts on dodge 4wd. front diff. cad jumps in and out on excel? any one seen this before??

 

Vacuum leak, misaligned axles, or any of a number of other possible causes. Verify good vacuum at CAD first, it that is ok, take it apart, and see what things look like inside.

 

Here is what i have done so far. I replaced the accuator at the diff. because it was siezed. It work great for about a week then it started jumping in and out. I was thinking it was a vacuum problem. check it at the cad and had about 20" . Took it apart again found that the plastic guides were gone and the new diaphram rod was bent from the torque. I needed it to work so i tried putting a nut that was a perfect fit around the rod to hold shift for over in the locked position. Worked for about 10 second of driveing then 4wd poped back out. Took apart again and found it to be bent even more and i ground a groove in the shift fork.

 

what do you think.

 

Something strange is going on there..... are the axles lined up properly? Does the collar slide across the axles smoothly? Proper fluid level in the diff? If things are bending.... something is definitely awry.

 

It does slide smoothly. but is harder to get it to line up do to the spines being ground a bit from it jumping out this last time. I just can understand why it would want to walk over like that unless the splines have a slight twist in them?

 

could the bushings be bad on the shafts to cause this??

 

its important for the collar to slide all the way over to the drivers side to engage the inner (intermediate) shaft. if it doesn't slide all the way over, it can pop off as things move around a little bit with their natural play.

any burrs, grooves, etc that interfere with easy slide on and off really screw up the system.

one way to fix it is to remove the outer axle, then collar, and clean up all the splines with a small file. the inner axle usually needs cleanup too, but since its fatter, mine required removal of the axle seal in the cad area, and the whole thing turned into a pretty big job.

as a temp fix, you might try GENTLY tapping the collar further towards driver side, and looking for a way to lock it into place. posilok makes a permanent lock, but its overly expensive, almost as much as a cable disconnect.

 

bushings hold alignment, and reduce play, and are important for smooth operation to engage/disengage. but once the collar is engaged, i don't think the bushings are the cause of your unexpected disengagement.

more like weak vac, weak cad, flimsy cad not holding the collar engaged.

 

way over priced perma-lok

edit....

link replaced with reasonably priced Alloy unit from Amazon (about $50)
it says Jeep Dana 44 and also Dodge 1500 Dana 44

http://www.amazon.com/Alloy-USA-4511.../dp/B008EVTNJQ