I came across a 3.5" lift for a good price. I put that on lift on. Not so after I started getting a "clicking" noise coming from my rear drive shaft. I thought ok, no big deal the rear drive shaft needs to be replaced because the angle is to steep.

This weekend I replaced the rear drive shaft and took the jeep for a test drive. I am getting a "humming" noise around 30mph. So after doing a ton of research I am guessing my pinion angle is out of whack!

I also have a front drive shaft to put in and I am worried about having the same problem up front.

Is my only option here to buy rear upper adjustable control arms and adjustable front lowers?

I am running the AEV 3.5" kit with 35" nitto trial grapplers. Its a 09 Rubicon.

Thanks!

 

Adjustable control are should fix the vibe. How much actual lift did you gain after installing? Any before and after measurements?

 

I have 3.5" lift, and yes you'd want atleast front lowers to set caster, and rear uppers to correct your pinion. Ideally all four adj is best for exact measure. Your rear pinion should angle should be dead even with your rear drive shaft. Your caster up front, should sit at 4 degrees leaning towards the back. Through projectJK, use the TeraFlex flexarm install write up, and the do-it-yourself front end alignement to see how to dial in your front caster. It made it much easier for me to dial everything up and understand why and what needs to be adjusted.

 

I did take some measurements before and after the lift, it ended up going up 3.75"

Installing the rear upper control arms and adjusting the pinion seems easy...

1. Take off the factory control arms.

2. Adjust the pinion angle up so it is in line with the drive shaft.

3. Adjust new control arms out to fit into position. Making sure they are both the same length.

4. Remove rear springs to install spring correction wedges.

5. Put jeep back down and torque down upper control arms.

This look right guys?

Thanks,

 

No.

Loosen the rear upper control arm bolts with the tires and wheels on the ground.

Put a floor jack underneath the pinion (not the differential, further towards the drive shaft)

Have the floor jack underneath the pinion and get ready to remove the stock control arms.

Remove the lower bump stops, if you have them. (Only way to remove the control arm bolts)

With the pinion supported, Remove Stock Control Arms. (You'll need to remove the lower bump stops)

Put the adjustable control arms in with the Heim at the frame side. Put the bolt through to hold it in place.



Now jack up the floor jack and start pointing the pinion at the transfercase. Your driveline and Pinion angle should be different by 1*. Just eye ball it.

Increase the adjustable arms as needed. Bolt them up.

Tighten the nut.

 

here is a before and after

before



after

 

My rear RK Correction Wedges were a @(!!@$

What I did was, disconnect rear trackbar, i dont have a rear sway bar link but you'll need to disconnect that too, disconnect lower shock bolts, jack the jeep super high till the coils pop out. i needed a coil compressor since i got 4.5" coils, put the rk wedges in, put coils back in, drop the jeep down, re-connect all the bolts.....

 

Thanks for the clarification! The pictures help a ton!

 

every jeep is different, but this is how long my rear uppers are to get my pinion inline with the transfercase.

(EYE TO EYE)




here are pictures of the pinion pointing towards the xer case

 

if youre anal, this is how you measure the pinion