[Blk2kTj]

I havent had my front driveshaft in for about a year now due to wered vibes I got with it installed.

It was a long tedious process that involved a front axle rebuild as well as a brandnew tom woods front driveshaft AFTER i had the factory one rebuilt/balanced/given a blessing by a driveline shop.

The only thing that hasnt been looked at yet is the front output shaft on my np231 transfer case. I just examined it from the outside and it has around a millimeter of play forewards to backwards in the t case.

Is that normal? I know even less than a mm of play in a ujoint shall cause vibes. the yoke dosent seem to have play up or down, just back to forwards. I may have messed up the install when I installed the SYE a couple years ago (I didnt have front DS vibes until after i regeared from 3.08 to 4.56.. the increased DS speed began the vibes at speeds about 50 mph) So the front output yoke may have been loose or whatever for 2 years but just didnt spin fast enough to cause troubles with 3.08 gears.

Does the front output shaft of the np231 utilize a crush sleeve? If so, I dont ever remember crushing one on install. If there is no crush sleeve, what should the front output shaft be torqued to?


thanks

__blk2ktj

[Blk2kTj]

Update:

I removed the front output yoke, cleaned the threads of the output shaft, ran the nut in to make sure its travel to the end was free, and bolted the yoke back up with some thread locker and squeezed it to 150 lbs.

At highway speeds you can at times feel that theres another spinning component under the seat, but it drives pretty decent! No vibes bad enough to warrant removing it again. Honestly, it feels absolutely like a typical lifted vehicle would feel. Some vibes, not too bad. It rides just fine.

The problem must have been with a loose output yoke. I must not have torqued it down enough or the lack of threadlocker allowed for the loss of torque on the yoke nut. There is still a tiny amount of play in the yoke/driveshaft system caused by a slight amount of slack in the output yoke/shaft. You can feel it but cant really see it.

To answer my own question, there shouldnt be ANY play in the front output yoke/shaft. Im sure a double in play could cause a 3 or 4 fold increase in vibes, especally with 4.56 gears.


thanks all,

__Blk2ktj