Between fixing my mushroomed ball joints and all the bolts I misplaced removing my suspension over the winter, I didn't pay much attention to which lower control arm was originally on which side. They look identical so I figured it wouldn't matter which side they were installed on. I did notice on a previous alignment sheet that the caster was 4.2 right and left, and now I'm 3.8 left and 4.5 right.

Did I install them backwards?

Yes, it is possible to install them backwards. If memory serves, there's virtually no difference between the two, so they may be interchangeable. They are officially different part numbers left and right, so there probably is a subtle difference. Don't ask me if there's any way of distinguishing left from right visually, 'cause I've never been able to see a meaningful difference.

Different part numbers and they price differently as well. Confusing. I've got prothane bushings in these arms, so maybe they are wearing differently, and that is why my caster values are different from before.

As I recall thre is a slight difference in length on them, I'm sure its not anything that cant be taken up with an alignment though.

turbosax2 said:

http://www.dsmtuners.com/threads/control-arm-id.317130/

Click to expand...

I was going to say, I know these control arms are marked very clearly from the factory if you are using OEM components.

turbosax2 said:

http://www.dsmtuners.com/threads/control-arm-id.317130/

Click to expand...

So if the ball joint and the chassis mount are symmetrical, then I should be OK if the arms are on the wrong side, the slight change of angle of the shock centerline shouldn't matter.

I'm not sure if that would have a negative impact or not. But if I were you, I would just check and fix if necessary with how easy of a job it is.

The difference is the positioning of the shock bushing, it's offset slightly, as if it had been pressed in too far. The rest of the arm is identical.

Last time I checked I think there was only one part # for both sides ? Oh, from the factory they have a big L or R in white paint on the side - if you clean them carefully the markings may still be there

The part numbers are the same for both sides. This is from Mitsubishi part Warehouse catalog.

That must be a somewhat recent change that they're the same now. They were not originally.

I just received a new set in the spindle kit and they are not identical. That screen shot isnt from caps or asa. For reference it looks like L means drivers side?