Finisher

Here is my setup:
*3 in Mopar/TF lift
*Dynatrac Prorock44 unlimited
*Adams 1310 driveshaft bolted to factory flange at transfer case
*Caster is 6* leaving the pinion at 4* yes I checked with my Phone app
* Transfer case is angled 6* towards the back of the Jeep
*Driveshaft is 7* down towards the front
I have a 12JKU Rubicon on 37-13.5. 17 TOYO RT. Jeep is geared at 4.88.

I have taken the driveshaft off to verify wether it was causing the problem, and the vibration goes away when the
Driveshaft is off. Verified that it was in phase and oriented with the factory balance marks.

I have read a lot of threads on this subject, on a lot of forums. I guess where I am getting confused is the joint at the pinion.
Does it need to be perfectly in line with the driveshaft or can it be off a little? I am guessing that with my measurements that I have about
3* difference between the pinion and the DS. Is this causing my vibration or should I get the DS rebalanced? I would need to get adjustable
Upper Control arms to set the pinion correct? Any suggestions?

ShutterBug

There is no phasing on a CV style or a double-cardan style drive shaft. Orientation does not matter.

Your drive shaft could be out of balance? It may be worth taking it to a local driveline shop and have it checked.

I thought I had this issue as well, turned out to be my pinion bearing. Not saying that this is your problem, but it's worth looking into.

kjeeper10

X2 imbalance

Finisher

I guess my concern was with the DS and pinion angles being the same or is that a non issue?

Biginboca

You've done all the reading so you probably already know the answer but don't want to hear it, lol

You typically want less than 2* difference between the shaft and pinion. I would have bad vibes at 3* on my set up. Of course it could be a balance issue but I would start with the pinion angle at 1.5.

Finisher

That's the number I have not been able to Establish from all of my reading but was kind of thinking that control arms might be the answer.
I just hate chasing problems with money, would much rather be well informed to make a better decision. When I started down this road with my
Jeep I started to just throw parts at it, learning there is more to it than just buying a suspension and big tires. Everything has consequences!

Any recommendations? Control arms?

ShutterBug

IDEALLY, the drive shaft and pinion should be in line. But that's going to be impossible without a caster corrected housing or you'll be so far out of caster it will be undrivable. Is the Prorock caster corrected? If you don't have adjustable control arms now, with 3" of lift, you should get them anyway to correct caster and to adjust the pinion angle.



Here's a good video from Bleepin Jeep that explains it well.

https://www.youtube.com/watch?v=5QQN52Vmllw

Finisher

So I think I will go with the control arms. Now to decide on which ones. I don't plan on these being a long term deal, just until I get enough saved for the Evo double D.

Prime631

I know this is an old thread but did the OP ever solve it. I have the same setup and issue with a PR 44 and a 1350 shaft.....I have a pinion angle of about 5.5, driveshaft angle of 7.5 degrees and caster angle of about 4.5.....been trying to resolve this for months.....replaced rebuilt shafts, tires, etc....convinced its my angle

kjeeper10

You should not be having issues with a corrected housing. Do you have a DL shop local who could throw it on a balancer ?