Help figuring out driveline vibes after belly up.

[Toad]

2006 TJ. Teraflex 4" LCG enduro. Adjustable arms upper and lower. NP231 with tera extreme short shaft sye.

Currently using a digital angle finder my driveshaft is 24.4 degrees. The pinion is set at 22.0 degrees. I am still getting decent vibes at speed and worse when on the throttle. My thought is that I am getting to much pinion rotation under throttle causing the pinion to rotate up causing the worse vibrations. I am thinking about rotating it down another 2 degrees and seeing if that changes anything. The driveshaft I am using is a older one that I had kicking around. I had Six States shorten and rebalance it. I guess I could have a driveline balance issue still. Any thoughts?

I also had the driveline and pinion set the exact same and the vibrations were worse. I think they were both set to 23 degrees

 

[Hickey]

What type of shaft is it? Double cardan, or single u joints at each end?

 

[Toad]

double cardan

 

[Toad]

So I adjusted the pinion angle down two degrees. 25.7 on the driveshaft and 20.5 on the pinion=WRONG

Then I adjusted the pinion back up to 22.9 which put my driveshaft at 23.9. That's the best it has been. I still have some vibration though.

So my options that I know off are drop the transfer case down or install a motor mount lift.

I already have clearance issues between the the transmission and and the tub of the Jeep. So in order to raise the motor any more I think I will have to install a body lift. Really don't like this idea. I am trying to keep it as low as I can for my wife.

Next option is to lower the transfer case 1 inch. I don't like this idea either. I think it will be my best option though.

 

[lhracing]

Ideal is having the pinion about 2 degrees down from the driveshaft. This will allow for some axle wrap under power which will put the pinion in-line with the driveshaft. You never want the pinion higher than the drive shaft.

 

[Hickey]

Pull the front driveshaft before you spend any money.

 

[gorillaxj]

I agree with Hickey pull the front and drive it to make sure it’s the rear.

Also you mention you had it balenced ect... was this very recent? You could have a bad u-joint that isn’t sloppy or obvious.

 

[Toad]

It was balanced couple months ago. Maybe a hundred miles on it or so.

 

[Toad]

So I have a Teraflex transfer case drop kit that came with my kit. I installed it and readjusted the pinion angle and still had the shake. I then pulled the rear driveline out and had Six States double check the balance on it. It was a little of balance but more than likely not my issue according to SS. I just took it for a drive with the rear driveshaft out of the Jeep. Front wheel drive. No more shaking Sweet finally getting somewhere. Unfortunately the rear driveline is in at the shop in Smithfield and I dont want to drive there tonight is this fog.

 

[RogueJeepr]

Mine has had a small vibration at 65-68 mph. I need to fix before the next trip.
Since moving I hardly get on the freeway anymore. Took my rear measurements.
driveline::::12.5
Pinion:::::::: 14 whoa[emoji33]
I think I have 3° shims that will be removed. Did a shackle box and forgot to remove those.

front.
Driveline:::: 6
pinion::::::: 5.5
caster:::::::6*