Hey guys just looking for some advice. A few months ago i had my transfer case rebuilt because i lost 2wd and 4h all i had was 4lo. the 4x4 didnt work very well before i had this rebuilt and i never really used it. after i got this rebuilt i put the truck in 4h and 4 low and the 4x4 works but like a clicking sound comes from somewhere under the truck. idk if it happened before the rebuild or not but the guy who rebuilt the case is a great mechanic and showed me the parts he put in the new case and the ones that werent worn so i doubt its the case making the noise. could it be something in the front axle causing this. when i accelerate the noise is louder than when i stay at a constant speed. also i drove a good distance in 4h the other day when it was snowing and the trans temp light came on. any ideas what this could be?

 

sounds like maybe different gears in the front.

 

A few things come to mind:

1) You have a bad u-joint in the front drive-shaft. This drive shaft stays stationary until 4-hi or 4-lo is selected. It is likely the little needle bearings inside one of the u-joint caps are dried-out, rusted an/or already pulverized and making the clicking sound... especially when accelerating.

2) The differential in the front axle is low on gear lube and/or you've got a bad bearing in there. Since you say the noise gets louder, I'd look closly at the pinion bearings as when torque is applied, the pinion will try to deflect off the ring-gear inside it's bearings.

3) If these other things check out OK, take a look at the CAD (central axle disconnect) in the front axle. If you look at the front axle, between the differential and passenger-side wheel, you'll see a bulge in the axle tube with a couple vaccum lines running to it. That's the CAD. Pull the cover off and you'll see the axle shaft is actually a 2-piece affair. The CAD uses a vacuum motor, a shift fork and a collar to connect the two axle shafts when either 4-hi or 4-Lo is selected on the transfer case. It is common for the vaccum lines to "rot" over time and not supply enough vaccum to slide the collar far enough to fully engauge the splines, though this usally results in quite a bit more than just a "clicking" sound. This is what the CAD looks like.

 

Yeah I just replaced the cad the 4x4 wasnt engaging at all i guess when i bought the truck somone had welded the shift fork to the housing? wierd i know. But when i get back home ( On military duty right now in NJ) ill check the other things out. Im trying to get this truck ready for some fun and some sled pulling so Id like to make sure everything is working right before i get on the track. Thanks alot guys

 

u joint at the front sealed hubs would be my guess when my plow trucks get that clicking noise when moving thats usually what it is