i found problem with rear drive shaft yoke wore out and bushing in tail piece extension of transfer case. bought new yoke and new bushing and installed them. when i tried to install drive shaft the yoke would not slide into transfer case. took some reading between out put shaft and new bushing and found the out put shaft was not centered. i did a run out of out put shaft at out put bearing and found .004 run out. took reading at end of out put shaft and found .055 run out. looks like shaft is bent how is this possible. any one know
this 1996 truck only has 68,000 mi on it. it has been sitting many years i am second owner

 

well if the yoke seized then there would compression on the shaft when the suspension flexes

 

the yoke was not seized that i know of

 

it might only happen intermittently when decelerating , or at a certain point in the suspension travel, etc. But it just takes a split second. Wear in the driveline has a tendency to spread.

 

There’s a number of different causes for excessive run out on the output shaft - mileage is not likely to be a factor since the truck has seen (relatively) little use in its life. Too much sitting can sometimes be just as problematic as too much use.

Did you try to wiggle the output shaft top to bottom and side to side? IME, some play is normal - but if the end of the shaft is moving more than about 1/8” then it’s likely an internal bearing is at fault.

Does the yoke fully seat? With the suspension at resting/curb height, There should be approximately 1/2” to 3/4” between the output shaft seal and the “U” of the yoke (not the U-joint, but the U shaped steel that the U-joint fits into). If it’s more than that, the driveshaft is too short and excessive wobbling is occurring while driving.

To properly determine if it’s actually bent you’ll need to disassemble the TC and remove the main shaft for inspection as it’s a solid steel shaft that provides both input and rear output for the TC.

If it’s actually bent, excessive tension/pressure from the driveshaft could be the cause as MMJ suggested. Check the rear axle mounts/springs to determine if there’s worn or broken components.

 

thanks for info. i am looking for used transfer case then i will just change it

 

Understandable, but make sure the driveshaft is the correct length for the replacement. There are several TC’s that will bolt up, but depending on the original truck they come from, the driveshaft may need replacement or modification. You won’t know until it’s installed.