I just got my JKU aligned today, and it's still got a little bit of a wobble around 45 mph. I'm not sure if maybe it's because the tires are worn a little bit due to previous misalignment or something else. Caster came in at 3.4/3.7.

Got all new Front & Rear Synergy Trackbars; Drag link (Drag link flip kit); Frame side trackbar bracket; Teraflex ball joints.

I'm thinking of swapping out the bolts in my factory control arms with the 9/16 bolt kit to see if that will affect anything. Does anyone know if I swap out the bolts one at a time, will affect the alignment? I don't wanna spend anymore $$ at the alignment shop.

 

It shouldn't affect it enough for it to matter either way. If you have adjustable control arms, get a angle finder. Check the angle before and after the bolts are installed. Then, adjust accordingly. You may want to try out 4-5 degrees, or anywhere in between. I would assume you'd have some driveline vibrations at that low of castor. Could be wrong though.

 

The difference between 14mm and 9/16 is 0.28mm or 0.01132 inches I don´t know how this can make any change ...

 

You spent all that money on parts, and you chose not to adjust the low caster?

Assuming that the trackbar bracket holes are not severely wallowed out, and the bolts are torqued down tight, swapping the bolts will have no effect on the caster. 'If' the holes are way wallowed out and the bolt is loose, and you replace the bolt and crank it down - maybe? A tiny bit? Not likely, but...

 

If anything just replaced the front to track bar bolts $10 or so.

 

If your just getting a random wobble at one certain speed then its probably tires. Get them re balanced. I can go all the way up to 90mph without any wobble or steering wheel shimmy.

 

Good general rule of thumb is that if it is speed induced it is tires, if it is bump induced it is something loose/worn out in the suspension.

 

I replaced the bolts on the trackbars.

To answer the question, about the low caster, I have adjustable uppers, but the alignment shop was trying to optimally dial it in to 3.5. I'm thinking of taking it back And telling them to adjust it out to 4.

However also a little side note, my camber was off on my passenger side by 2.4 degs about 2 months ago, so I had to put in a 2 deg offset balljoint to get it back into spec. I'm wondering if moving the caster forward yesterday was pushing the camber back out.

Sorry for the sloppy reply. Am on my phone at Harbor Freight.

 

Yeah, am going to look into the tires too. Think that may be the culprit.

More to come.

 

I think you need lower adjustable control arms to increase the castor up front.