They do seem to be pretty stable in this respect. A couple of years back I changed my strut assemblies (installed Bilstein B4s) and the alignment never moved.

I never even aligned my car after changing the tension struts and ball joints a few years ago. I was ready to, since if the new ones had a different length than the old ones I could see that I might need to. But the car tracked perfectly fine before and after.


Honestly if you are bolting something on that is not adjustable, the only reason it would need an alignment is if it is a different size/shape than the original, or if you can bolt it on in a different position than the original.


It's my opinion, speaking as a mechanical engineer with a background in vehicle dynamics, that we align our cars way too much -- after a tire change for an example. There is nothing you can do during a tire change that would make you need an alignment. It is just an upsell from the tire shop. I actually have not aligned a car in almost twenty years. I would only recommend alignment if you have a tracking issue or if you have a tire wear issue. Otherwise I would suggest it's a waste of money and half the time the alignment is worse when you get it back. Alignment techs are generally sloppy with their work and they have wide ranges of "acceptable" alignments.

I, too, haven't had a professional shop align any of my vehicles in over 20 years, as well, with two exceptions.


When my truck and camping trailer hit a MOAP (mother-of-all potholes) at 75-80 mph one Sunday afternoon (of course, when no tire shops were open), and three of the tires on my 2500HD received belt/cord damage.

I should've found a motel, and stayed 'til I could replace the tires, but I had to be at work at 6 am the next day, so I drove home the remaining 150 miles, at 55 mph because though I put the spare on the front, the remaining two busted tires were on the rear, and driving at speeds above 55 mph was shaking the whole truck too violently to go faster (I'd check pressure and temperature of the two bad tires every 50 miles). Drove a backup car to work, and went to the nearest NTB (with tires on sale!) later the next afternoon (driving the truck on side streets).

I replaced all four tires with new All-Terrains, and as a precaution, had them align the truck, too. The report sheet showed it was just barely out of spec, but I aligned it anyway (why not, it was already on the rack).That was about 7-8 years ago.

The previous time I had an alignment was in 2004, IIRC, when I took my drag race Chevelle to a "drag race alignment" specialist that was popular with my racing organization. My Chevelle was doing 12" wheelies (after installing a more powerful engine, a trans-braked powerglide, a high stall converter, and 4.88 rear gears), and would dart to the left upon touchdown, and sometimes steered left at the finish line, at 125 mph or more. It still did that even after i increased the air pressure in the slicks from 10 psi to 15 psi, so I decided to try a drag race alignment. The specialist made it better, for sure, and it was worth the money. The car never veered left anymore, at start nor finish line.

I've self-aligned three other vehicles in the past twenty years (two trucks and one car, all 2wd/rwd) using tape measures, bubble levels and right-angle framing squares. But that was on my friend's level shop floor, and my home work place (outdoor) and even my paved garage floor are anything but level, so if/when I think I need an alignment again, I'll take the vehicle to a shop.