What is the proper front driveshaft angle

I have a 89 xj, 4.75" lift on adjustable upper and lower arms,hp d 30, new front shaft and 242t/case. Heres my problem I get pretty good vibes from my front shaft between 50mph and kind on goes away at 65mph but is still present. I dont think my front axle is positioned correctly, my pinion faces up and my coils are bowed to the front. Should it be more or less level rather than pointing up?

it should point towards the TC. there is a good write up on go-jeeps page (sorry I dont have a link handy) that gives pinion angles etc. Sounds like your kind of in the same boat as me. I have same jeep but in a 94, and same vibes. I've tried a LOT of stuff and havent figured it out yet. Could be your front shaft needs rebuilt. I did all of mine except for the centering ball (which is probably the culprit) I just couldnt find one locally when I had it all torn apart.

edit, heres that link, go to the DIY alignment page..

Gojeep Home Page

if your coils are bowed, you need longer/adjustable control arms....these will also help you dial in your caster and your pinion angle.

I now have a new shaft as well as a rebuilt and a used shaft, they all do the same, I do have adjustable upper and lower arms.

David Rizor said:

If you getting front drive line vibration at hwy speeds then you’re trying to do something that a 231 case was not designed for!

Click to expand...

Driving in 2 wheel drive?


Is the new shaft a *new* shaft, or another old shaft?

David Rizor said:

Because of the design of the front axle pinion angle is not important, Castor is! Set castor between 4 - 5 degrees . What you end up with for pinion angle is what you get! If you getting front drive line vibration at hwy speeds then you’re trying to do something that a 231 case was not designed for! The vibration your getting is coming from the spider gears speeding up the drive shaft.

Click to expand...

meh, I duno if I would be as bold to make that statement. Your right, but not completely IMO. Sure it wasnt meant to do that, so a sacrifice has to be made, most of the time you cant have both. Castor at 4-5 degrees, is running less castor than stock spec in the first place. and chances are, at that angle you might have found the happy medium resulting in no vibes. But from all I've understood about the whole deal ispinion angle is gonna take priority over castorsand personally I'd rather deal with a little wandering on the road from castor being off. Than blowing up my TC or pinion seals from bad angles.

I'm running a 242 t/c with a new shaft with spicer hardware , I've been dealing with front shaft vibes since the lift IN 2WD. They were somewhat liveable in the summer with 32's and 4:10's at highway speed, but much worse with 235/75/15 winters. but I soon learned liveable still causes damage. It ended up taking out my front pinion seal,bearing and front yoke and u-joint. This fall/winter I decided its time to fix this problem. I swapped in a converted disco to non disco hp30 with adjustable upper and lower arms and a used front shaft, vibes improved but were still there. Just for fun tonight I adjusted the upper arms to the pinion points directly at the tc output and vibes slightly improved though my coils are now quite bowed and the end links are hitting the coil springs,steering is now very touchy. I plan on getting some pics up tommarow as well as some measured angles.help! thanks!

I wouldn't whine if I didn't have to hit the highway so often, last summer I pulled the shaft and carried a 8mm and 13mm all the time, but now its winter and not a bare road in sight

after *much* searching and reading I will try another shaft, from what I've read there is no reason for vibes with the pinion pointed straight at the t/case flange.

David Rizor said:

Because of the design of the front axle pinion angle is not important, Castor is! Set castor between 4 - 5 degrees . What you end up with for pinion angle is what you get! If you getting front drive line vibration at hwy speeds then you’re trying to do something that a 231 case was not designed for! The vibration your getting is coming from the spider gears speeding up the drive shaft.

Click to expand...

Incorrect, pinion angle takes precedence over caster any day of the week.

David Rizor said:

Because of the design of the front axle pinion angle is not important, Castor is! Set castor between 4 - 5 degrees . What you end up with for pinion angle is what you get! If you getting front drive line vibration at hwy speeds then you’re trying to do something that a 231 case was not designed for! The vibration your getting is coming from the spider gears speeding up the drive shaft.

Click to expand...

Whoops double post.

I found slight play in the new(was new) front shaft I have, not rotational play but if i put one end in the vise grab the other end and try and move the middle there is slight play. all three shafts seem to have the same amount of play.:dunno: this cause vibes (slight steering wheel and seat of pants vibes) and droning sounds at highway speed?

On a side note, that Go-Jeep homepage is a wealth of info. Good stuff.