jordy

That would pretty much eliminate the axle being the issue, unless they somehow exactly mirrored the previous setup exactly. I'd be looking at transfer case related issues, or even something further back that is transferring the hum through the driveline.

allcarfan

Update. Took jeep to a hot rod shop ive used in the past. They measured pinion angle and caster on their level, drive on lift. Pinion angle...6-7. Caster 12/13.

Adjusted upper control arms and brought pinion angle down to 2 and caster to 8.

Eliminated every clunk, hum, and grind immediately.

nthinuf

Good to hear. I haven't touched my caster in a few years, but if I remember right, 8* is what I'm set at also.

I still need to get out to pick up another angle finder, though. Still want to compare the finder numbers to the last printout to see how close the various spots are to actual.

allcarfan

Yeah....im still trying to get the shop to get me the printout. I know they are busy, but cmon. Ive spent over $15k with them over the past 3 years.

I texted the owner with how i solved my own problem and the only response i got was a thumbs up emoji.

Live and learn.

Jeep feels like a completely different vehicle now

TheDirtman

I thought I told you that you had too much caster.

allcarfan

You did, and i appreciate that. It was my assumption also. I just needed some good, level ground to see how much was too much

SoK66

Dirtman may remember the exact source, but it was either Currie or Synergy that had a piece on best caster with larger tires being 4.5 degrees. They gave more than 5 degrees a serious thumbs down, claiming high caster a source of death wobble and turning radius issues.

allcarfan

Even on an aftermarket axle with caster built in?

nthinuf

" Dynatrac is currently manufacturing the ProRock 44 Unlimited edition axle which includes more caster. These axles have 10 degrees of separation between the pinion and caster axis. They are configured for a nominal 7 degrees caster and 3 degrees pinion angle. The axle can be adjusted using the control arms between 6-8 degrees caster and 2-4 degrees at the pinion. "

Dropping to 4* caster would put the pinion at 6 degrees

https://www.dynatrac.com/downloads/P...20FAQ_revK.pdf

SoK66

Yes. 4.5 - 5 degrees will give you 5 degrees on the pinion, which should be nearly dead on with a 3-4" lift.