hey guys.

im in the middle of trying to find a bad vibration rotational grinding on my truck.

well today to removed my front driveshaft to try and eliminate the front chunk from being the problem. so i go to take it for a test drive after removing it and the pinion was still turning. i though we had vaccum disconnect at the hubs. (ADD). this leads me to think that my diff isnt disengaging. (though the 4wd light in the cluster still turnes off.)

does you guys, and gals front drive shafts turn all of the time?

any thoughts?

THANKS!

 

Your axles do, but when the ADD disengages, the pinion flange should remain stationary. Thus if the pinion turns when in 2wd, then you have a ADD malfunction.

 

so my front axle in locked in right now... the only reason why it dosent stay in 4wd is because of the tcase is in 2wd.

what usually goes wrong with our ADD?

thanks!

 

The Automatic Disconnecting Differential system explained:
http://www.off-road.com/trucks4x4/ar....jsp?id=399612

 

I'd check the vacuum lines by plugging the ends with my finger and having someone engage 4wd. Then, if there was a vacuum, open the little access panel on the ADD section of the axle, see why its stuck.

 

Wow.. That article was pretty informative.. In the bottom how he described how to permanently lock the ADD system... Is that for when you do a manual hub conversion or something?