I have an automatic tranny/case on my rig. I just finished welding up a new square front driveshaft. The old one was spinning on the freeway in 2HI and the U-joints blew up, destroying the CV joint and making the front half fly off on the freeway. I have checked my hubs and they are freewheeling, but somehow the T/C is still spinning the driveshaft when it is in 2HI. I test drove it on the road and I am getting bad vibrations from the front end over 35 MPH. I suspect that it is the T/C. Any ideas on how to fix this? I really want to get this rig back on the trail again.

 

Check linkages to ensure it is actually engaging 2hi. Your new bad vibration is from your square driveshaft and the tc spinning it at high speeds. IIRC, square driveshafts are generally used for rigs that don't see much speed in 4wd.

 

Are you sure it's not supposed to spin at all times.

The rear drive shaft spins whenever the vehicle is in motion.

 

I am sure that it is not supposed to spin at all times. I checked the linkage and it appears to be in order. It used to run fine, but it might still be the locking hubs. I have another set on order and I will swap them out and check again.