2-whl or 4-whl alignment after new tires?

Hi guys. I just got new tires on base (I'm in the military). The shop doesn't do alignments though. Should I go and get a 2 wheel or a 4 wheel alignment?

There is no way to do a "4-wheel" alignment on an XJ, as the rear axle has no adjustments for it's position on the chassis.

BTW--on an XJ, there is no adjustment for camber on the front wheels either. It's fixed at the time of welding the front axle housing together. If the camber is out of spec. offset ball joints can be used to bring it back in spec.

When the front end shop does the alignment, they will only be able to adjust caster and toe-in.

In theory, at least, a 4 wheel "thrust angle" alignment might be better than a plain front job, because it sets the front wheels parallel to the rears. Whether or not that's an issue may depend on whether the vehicle has been tweaked out of square by wheeling or accidents.

Matthew Currie said:

In theory, at least, a 4 wheel "thrust angle" alignment might be better than a plain front job, because it sets the front wheels parallel to the rears. Whether or not that's an issue may depend on whether the vehicle has been tweaked out of square by wheeling or accidents.

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In theory, yes, a thrust angle alignment is better. The kicker to this, though, is that on an XJ, there is no (built-in) way to adjust the position of the rear axle relative to the chassis so if you find the axle out of alignment with the chassis, you are kinda stuck.

It's not like you have control arms with adjustable bolts/slots, like seen on some coil sprung axles.

AZ Jeff said:

In theory, yes, a thrust angle alignment is better. The kicker to this, though, is that on an XJ, there is no (built-in) way to adjust the position of the rear axle relative to the chassis so if you find the axle out of alignment with the chassis, you are kinda stuck.

It's not like you have control arms with adjustable bolts/slots, like seen on some coil sprung axles.

Click to expand...

I think the idea is that even if the axle is out a bit, you can adjust the front wheels in parallel with it. It won't keep the vehicle from dog-tracking, but it might save the tires.