The rear drive shaft for my 1997 F150 extended cab 4x4 automatic transmission 4.6l has a vertical crack that goes about half way down between the arms for the U joint.at the differential end of the shaft. Can this be repaired or should I replace the drive shaft.

 

I think it would be pretty easy to find a used one at a junkyard. Can it be repaired? Probably... should it be repaired? Probably not. I'm betting it would probably be cheaper to pick up a used one anyway. Then you wouldn't have a driveshaft that's had a crack repaired... just my .02

 

^agreed. I wouldnt challenge a part as critical as a driveshaft by repairing a crack. Find one in good shape and swap it out

 

JMO but if you start to here a whistling sound, pull over and quit driving.