Basic Do-it-Yourself Jeep JK Wrangler Front End Alignment

Murfphy

Member
So I did everything that was written and suggested to me by all you guys. Eddie is the man for this write-up. Saving people money for sure.

I followed everything but UCA adjustments. I did the LCA to the 4 degree standard.

I read this thread and seems like it doesn't matter but I see in other places to use the Upper control arms for caster and ùse the lower for pinion angle?

I'm going to get the 1350 DS front and rear next. I'm just not sure about the rear pinion angle lineup for the transfer case blowing up deal.

I'm looking around for info on the DS thing. I know Eddie mentioned it earlier. I'm just really green to all this and need a fisher price explanation for "My First Drive Shaft Install".

I would like to say she no longer floats at highway speeds! I like driving her now.

I really thank you guys!

I'm looking to buy the DS and a 4040 shower kit in the next week or two. I will look to buy thru WOL amazon for all my purchases.

Thanks guys and thanks Eddie.
 

WJCO

Meme King
I read this thread and seems like it doesn't matter but I see in other places to use the Upper control arms for caster and ùse the lower for pinion angle?

Caster and pinion angle cannot be adjusted independently of one another. Any arm adjustment will change both. Your lower arms are really there to position the axle centered in the wheel well. Then the uppers are adjusted to correct your caster. All you need to worry about is the caster. The 4.2 degrees from factory is designed to compromise a balanced caster angle and pinion angle. However, usually with a set of adjustable lower arms on a lifted jeep, you can obtain an ideal caster angle without pushing the axle too far forward to hurt anything.

I'm going to get the 1350 DS front and rear next. I'm just not sure about the rear pinion angle lineup for the transfer case blowing up deal.

I'm looking around for info on the DS thing. I know Eddie mentioned it earlier. I'm just really green to all this and need a fisher price explanation for "My First Drive Shaft Install".

Don't need to really even measure. Just make sure the rear pinion and rear driveshaft are pointing right at each other like the picture below.

IMG_20171112_132830_104.jpg
 

Murfphy

Member
Caster and pinion angle cannot be adjusted independently of one another. Any arm adjustment will change both. Your lower arms are really there to position the axle centered in the wheel well. Then the uppers are adjusted to correct your caster. All you need to worry about is the caster. The 4.2 degrees from factory is designed to compromise a balanced caster angle and pinion angle. However, usually with a set of adjustable lower arms on a lifted jeep, you can obtain an ideal caster angle without pushing the axle too far forward to hurt anything.



Don't need to really even measure. Just make sure the rear pinion and rear driveshaft are pointing right at each other like the picture below.

View attachment 290570

Awesome!

Thanks WJCO!:clap2:
 

clos0791

New member
I just checked my caster on the hole next to the differential with my angle locator. It read right at 89-90 degrees. Am I Good?

Thank you Eddie for all this useful DIY write ups. Much appreciated.

Sent from my SM-N950U using Tapatalk
 

MericaMade

Active Member
Great info here, thank you! I have a question but will give you my specs to help. I have the 3 inch Evo kit on 35 BFG KM2 and caster is at 4.7. The jeep seems to float around a lot since the lift. Should I add or remove caster? At what point is positive caster bad?
 

WJCO

Meme King
Great info here, thank you! I have a question but will give you my specs to help. I have the 3 inch Evo kit on 35 BFG KM2 and caster is at 4.7. The jeep seems to float around a lot since the lift. Should I add or remove caster? At what point is positive caster bad?

4.7 is great. The more caster the better as long as you don't get driveline vibrations. If it's floating around, make sure all parts are tight including your track bar. And check tire pressure, if it's really high, it can feel flighty.
 

MericaMade

Active Member
4.7 is great. The more caster the better as long as you don't get driveline vibrations. If it's floating around, make sure all parts are tight including your track bar. And check tire pressure, if it's really high, it can feel flighty.

Thanks....

I was thinking of trying 6-7 degrees and see if that helps, but if you think that will bring in drive line vibrations, then should I even try?

Also, is it 6 degrees difference taking a measurement from the front of the axle and top of the ball joint?
 

WJCO

Meme King
Thanks....

I was thinking of trying 6-7 degrees and see if that helps, but if you think that will bring in drive line vibrations, then should I even try?

Also, is it 6 degrees difference taking a measurement from the front of the axle and top of the ball joint?

6-7 will be too much on a factory axle. If your ground is a perfect horizontal zero, the imaginary line between your lower and upper ball joints should point rearward about 4.5-5.0 degrees.
 

tbreaux

Member
Hey guys, was researching the caster topic and ran across this thread. I'm running an EVO double throw down, 40s, and a dynatrac prorock 60. Very "flighty" highway driving. Should I still be in the 4.5* - 6* range?
 

wayoflife

Administrator
Staff member
Hey guys, was researching the caster topic and ran across this thread. I'm running an EVO double throw down, 40s, and a dynatrac prorock 60. Very "flighty" highway driving. Should I still be in the 4.5* - 6* range?

Caster on your ProRock 60 should be 6°. Being that you have locking hubs, you could always add a bit more too and without ill effect. That being said, your flightiness is probably coming from your ram assist.
 

tbreaux

Member
ok thank you. With a level jeep and on this axle, where is the best place to take a reference measurement, the front "holes" of the turtle, or the "fins" of the turtle? On the holes, I am seeing 4.5* (forward) which would mean i am sitting only on 1.5* of caster?
 

sgt381fl

New member
Thanks firegz Image1531526292.007631.jpg
 

Attachments

  • Image1531525992.430251.jpg
    Image1531525992.430251.jpg
    282.2 KB · Views: 135
  • Image1531526875.425583.jpg
    Image1531526875.425583.jpg
    47.6 KB · Views: 133
  • Image1531526972.503006.jpg
    Image1531526972.503006.jpg
    281.3 KB · Views: 138
Top Bottom