Drive Shaft Vibration - After lift (1 Viewer)

[Azca]

Ladies and Gentlemen,

After lifting I had a drivline vibration on decel. So, went to Mr. Landtank and ordered a front DC shaft. Installed the shaft and now the growl is ever present and tad louder. So, below are the specs and what I am running into. For a short read, I have a 2.9 degree difference between the shaft and the face of the u-joint (see pics below).

Question: Will changing to 4L, 5 or 5L delta arms help to address this?

I have the installed a 3.5" Dobinsons lift with the following:

• C97-144VT front coils - 3.5"
• C97-145VT rear coils - 3.5"
• MRA45-A912 front 4" length shocks for additional travel
• MRA59-A687 rear 4" length shocks

Center of hub measurements to fender: Front 24, Rear: 24.5

I have not weighed this before starting all the work on her. The following is what I have added which would alter the vehicle's weight:

Dynamat sound deadening throughout the vehicle and additional insulation
New mass backed carpet

• Front
  • 4xlabs bumper
  • 12k winch with synthetic rope
  • Front skid (25 lbs)
  • Dual batteries, the largest that will fit in the battery boxes.
  • Baja Designs LP9s
  • Hydro boost brake system with PSC steering reservoir.
• Mid vehicle:
  • White Knuckle Sliders
  • Skid plate (cant remember who – also covers xfr case and replaces factory cross member)
• Rear
  • 4xlabs rear, dual swing out bumper with 3 gas can carrier and tire carrier.
  • High lift jack
  • Puma compressor and mount
  • Tailgate storage (Delta)
  • Delta attic rack
  • WitsEnd quarter panel mount with Amplifier
  • No current plans for a drawer storage system but thinking of a Dometic Cooler.
  • Removed rear seats
  • Removed rear tire carrier from under the vehicle.

 

[Rusty Marlin]

To boil all that down>>> The front pinion needs to point staight at connecting (lower) shaft of DC shaft assembly. I image you do have quite the growl at 2.9* off. I was only 1.5* and I had a critical speed issue at 68-75. Under that was OK and over that was...better, but not what anyone would call good.

You need to figure out which way that 2.9* degrees is off. Does the pinion need to rotate up (closer to the engine) or down (away from the engine)?

If the pinion needs to move up you need to get closer to the stock radius arm offset. And conversly if the pinion needs to be lowered to bring it into alignment with the DC shaft you need taller lift arms.

Based on my expireance with this issue, I went from Delta 4 arms to Delta 2 arms to fix my miss-aligment.