to much castor
JK Enthusiast
Joined: Mar 2008
Posts: 184
Likes: 1
From: VA
Caster isn't a bad thing. In fact in many vehicles, MORE caster helps with steering stability.
But, as previously note, Caster and driveshaft angle are inextricably linked. You can't adjust caster without negatively effecting the angle of the driveshaft.
Think of it this way... as you increase caster, you're rolling the pinion of the axle towards the ground. The driveshaft joint depends on a neutral relationship between the pinion and the driveshaft itself. By rolling the pinion down (adding caster) you're increasing the stress on that relationship between driveshaft joint and driveshaft.
This is why the vibes went away. You did lose a little return to center, and straight line stability by running less caster.
But, as previously note, Caster and driveshaft angle are inextricably linked. You can't adjust caster without negatively effecting the angle of the driveshaft.
Think of it this way... as you increase caster, you're rolling the pinion of the axle towards the ground. The driveshaft joint depends on a neutral relationship between the pinion and the driveshaft itself. By rolling the pinion down (adding caster) you're increasing the stress on that relationship between driveshaft joint and driveshaft.
This is why the vibes went away. You did lose a little return to center, and straight line stability by running less caster.
JK Super Freak
Joined: Jul 2008
Posts: 1,934
Likes: 0
From: Middle of no where
If caster and drive shaft angle are correct from stock, and you mod it, then once caster is back in spec, drive shaft angle will also be in spec. Since the two cannot be adjusted independently, this would be my goal. I wouldn't try to "add" more caster than necessary, because then the drive shaft angle will be incorrect. Before any mods, you really should get a baseline alignment, so you'll know how much caster you have initially, and where to put it back when all the mods are done. Caster does not care how big your tires are. It's effect on steering will remain unchanged. I think this is where most people open up this can of worms. They try to dial in way too much caster and end up with driveline vibrations.