-8 degrees of caster and other alignment / geometry issues

[habitat259]

So I was working on my girlfriends 97 auto 4.0 TJ because of some issues when alignment. Specs are 4 inch lift, fully adjustable control arms (no idea the brand), adjustable front track bar, Slip yoke, Ford 8.8 in the rear) PO would wheel it, but my girl friend is looking to use it for a daily more then anything.

This weekend I decided to do a driveway alignment to dial in the toe and straighten out her steering wheel. I noticed some bump steering and thought to start there. As I was working on the toe I noticed that the angles of the drag link and Track bar seem to be off.

It looks like PO put a dropped pitman arm on it and has thrown off the angles (I'll post a picture and hopefully someone can confirm for me).

I decided while I was down there to check on the caster since on the highway it seems to be all over the place.

I used the level on my phone and placed it along the front driveshaft and also along the front diff (see photo for where I placed the phone for measurement) and got -8 degrees of caster!

I've never checked caster before so maybe I did it wrong but what from I read online the Jeep is having all the symptoms of caster being off I just didn't think it was that far off. I believe caster should be between 6-8 degrees so at -8 that's just crazy. Until I can get it to an actual 4x4 shop for an alignment should I just adjust the uppers on my own for the time being?

Long story short:
Should I go to stock pitman arm from what I believe is a dropped?

Did I measure the caster angles in the correct spots and if so, should I adjust front upper CA to bring the caster back between 6-8 degrees?

 

[jeffmarion]

They did a crossover steering set up on this, while not addressing the Trak bar angle. If possible, I would go back to the original Y link steering and stock pitman arm.

Since they did the cross over steering, they more than likely drilled out the TRE knuckle holes and you will need to get inserts to get your original taper back.
https://www.tmrcustoms.com/products/tie-rod-end-inserts-jeep-taper-tj-lj-xj-zj-mj

 

[habitat259]

@jeffmarion

Sweet thanks for the insight.

After looking into it more I thought I would have to get all new knuckles but these inserts are going to be super helpful. Ill be switching it over to the original Y link set up!

 

[OldBuzzard]

@jeffmarion

Sweet thanks for the insight.

After looking into it more I thought I would have to get all new knuckles but these inserts are going to be super helpful. Ill be switching it over to the original Y link set up!

That should help with the bump steer.

I wouldn't use the diff casing for caster measurement. That will give you pinion angle, but the ball joint framework (whatever it's called) at the ends of the axle are mounted at a different angle. You need to measure at the axle ends (notoriously difficult to find a good spot). One thing to try is on top of the upper ball joint. But keep your tools straight forward and back, because that sits at a compound angle, and little movements will change your reading.

 

[habitat259]

@OldBuzzard sweet thanks for the tips ill have to check it again and see what comes up.

On another note, i was looking at my track bar and noticed that it has a drop bracket on the axel. If I were to remove and use a stock pitman arm until I can get the original steering on will that create more problems then it would solve? The frame side is the standard mounting point (i think)

 

[Jerry Bransford]

Get rid of the passenger side dropped track bar mount and replace the dropped Pitman arm with the factory OE Pitman arm. Those two have combined to have really screwed up your steering geometry.

Great (!) decision to return the steering system to the original inverted-Y geometry. A Rock Jock Currectlync Heavy Duty Steering Kit would be a great choice, it's well known as a superb upgrade. My previous and current TJ both run it.