Number of Shims LCA.

[Raven]

Stock running height with four cylinder. I pulled the front axle out. The po did a crap job at converting it over to 4WD. It now has the straight axle back in it. Now I’m stuck. I’ve done searches and only seem to find shimming for lifts. Can anyone let me know how many shims on the lower control arms are used to adjust the front so I can drive it safely for a complete alignment at a shop? 

[fiatslug87]

There are shims of different thicknesses. Mine had a different number on each side from the factory.

[dasbulliwagen]

Just put in what was similar to what it was originally. It only adjusts caster, so you'll have no issues driving it to get it aligned even with no shims in it. Just don't go too fast before you know your caster angle is correct. You can adjust it yourself if you want to. Pull all four wheels off and put same height Jack stands under the front and rear axles so full body weight is on the axles. Then get an angle finder tool and set it on top of the upper ball joint. This will give you your caster angle and you can adjust with shims to get it where you want it. Spec is 5.5-7.5 degrees positive. If you do this part yourself, you won't have to worry about if the alignment shop does it or not. 

[JustEmptyEveryPocket]

14 minutes ago, dasbulliwagen said:

Spec is 5.5-7.5 degrees positive. If you do this part yourself, you won't have to worry about if the alignment shop does it or not. 

This all the way. I took my truck to a shop where the machine read 3.5*+ caster. And the technician said that was factory and I was good to go. When I pressed him he said he didn't know how to change it on my truck and that anything over 3 degrees is completely safe to drive on. He kept insisting that Jeeps came with about 3* from the factory.

 

I took it home and adjusted it myself. After playing around with it a little bit I went with 10*. I know its way over spec, but it gave me the best on road feel. Never trust shops, at least around me.

 

Do it yourself so you know its done right. Set caster as described above, and set toe-in with a tape measure. Drive away happy thinking of all the money you just saved yourself.

[Raven]

The guy I bought this MJ from really just threw it together. He did put the rear lower control arm adjustment. He just bolted it together.

it didn’t show anything in the Haynes manual. And I thought I had taken the caster adj bracket with the sh8ms off my MJ. I finally decided to check. I never took them off. The skins are looked the same thickness. There are six onerous them. So I installed them on our sons MJ. Thanks everyone. I appreciate the help. 

[AZJeff]

Late factory spec. for the XJ/MJ caster is 7 degrees preferred, with a range of 5.25 to 8.5 degrees allowed.

 

The max. difference in caster from one side of the vehicle to the other is 1.25 degrees or less.

[Minuit]

It's important to mention that on 4WD vehicles, the same adjustment controls pinion angle and caster angle, with a correct pinion angle having priority. On 2WD vehicles, dial in as much caster as you want, but on a 4WD truck, make sure the pinion angle is correct.

 

The 1990 FSM specifies an allowed range of 5 to 9 degrees, with 6 degrees preferred.

[derf]

I'd rather have a good caster angle.  A Jeep doesn't drive very well if the caster angle is way off.  On a stock height Jeep, the good caster and pinion should be together.  As you lift more, the pinion angle will be further off.  You can split the difference up to a point.  But as you get really tall, everything gets out of line.  You could rotate the Cs if you can cut and weld.  Or you can compensate with a double ended double cardan driveshaft.  That would be my preferred direction.