Steering wobble & rear drive shaft angle

[jeeptraveler2004]

Hi there,

I have 2004 TJ Rubicon. I have upgraded from 4 inch lift to 5.5 in the rear with heavy duty coils. In the front I have added 1.5 inch coil spacers. I am running 35inch Falkens.
I also replaced upper rear control arms to adjustable once, so is rear and front track bars.

My problem is: I get into sway around 35-50 mph on any road and death wobble if I uneven pavement. Alignment and tire balance have been done (didn’t help.) My front and rear axles are centered. I have tried to set a pinion angle of rear drive shaft, it seams going higher angle helps, which is strange, because I don’t have yoke eliminator.

I have longer drop pitman arm I want to swap, so far had no luck removing PA nut... will try again.

Anyone can help with suggestions?
Some pics might help.


Sent from my iPhone using Jeepz.com mobile app

 

[JPNinPA]

Steering wobble & rear drive shaft angle

First
DW is usually due to a bad or loose track bar. Other bad components and alignments start the oscellation that continues untill the vehicle slows or stops. Classic DW starts at 65mph snd stops at 70mph.
So verify the track bar bolts and bushings are tight. The stock axel side bolt can be upgraded to a larger size.
Then perform a dry steer test and identify any loose or failed components. Ball joints, TREs, wheel bearings, steering gear slop, control arm bushings...
Fix what you find loose.

Second -alignment
Did you get an alignment by a 4WD shop???
With lots of lift the target values change and most places do not have the new targets.
5 in of lift and adj control arms to correct pinion angle will put caster below critical angle. This will allow you will wander. Steering will be touchy & you will be constant correcting your steering.
Not having the track bar and drag link parallel will lead to bump steer when you hit a pothole. So DO NOT use a drop pitman arm, keep it stock.

Wheel balance and tire pressure make a difference in wander and DW. Do not over-inflate. Use the chalk method and keep pressures within 3-5 lbs of each other.

Lifts above 4 in you may consider long arms or mid arms to minimize shock and wear due to control arm angles.

Third -driveline vibrations
Now front and rear drive shafts can cause vibrations but not usually DW. Check u-joints for slop and replace if worn. Same for axel joints.
See below graphic for correct setup based on driveshaft and joints you have.
An engine lift and/or lowering skid plate or low profile trans mount can help with angle adjustments.




Never look down on anyone unless you are helping them up - Jesse Jackson

 

[JPNinPA]

Steering wobble & rear drive shaft angle

BTW you need bump stops.

And your front sway bar links; one looks upside down. One side top is long the other the bottom is long.

Regards,
JPNinPA

Never look down on anybody unless you're helping them up. -Jesse Jackson