Doing suspension work. Need alignment?

[HawkeyeScott]

I'm going to put in new strut/spring assemblies, stabilizer bar links and stabilizer bar bushings on my wife's 2007 Chrysler Pacifica (FWD).

Based on these repairs, will an alignment be needed afterwards? Thanks a lot.

 

[eljefino]

If your strut holes are round, no. If they're oblong, yes.

Put the big huge bolts in finger tight, then shake your strut where it meets the knuckle. Moves in & out? You need aligning. No? You don't.

Same with the upper strut mount. If the holes are set up so you can wiggle it around, you need aligning.

 

[Donald]

I would say yes. When was the last time it was aligned?

 

[t1snwrbrdr12]

Technically, yeah. The strut to knuckle could have a bit of play and throw camber off. The car could have been aligned to slightly bent parts in the past. The new parts could be slightly off in any dimension throwing alignment out, even if not noticeable driving it could show up in abnormal tire wear and by then it's typically too late to save the tire.

 

[PandaBear]

Struct, yes, shocks, no.

Supposedly the geometry of the suspension has no shock in it, and the ride height won't change (in theory) just spring and various arms, bushing, etc. Struts is part of the geometry so every time you change one out it will affect the geometry.

I personally would still do an alignment just to sleep better, regardless of struct or shocks.

 

[bdcardinal]

Originally Posted by PandaBear
Struct, yes, shocks, no.

Supposedly the geometry of the suspension has no shock in it, and the ride height won't change (in theory) just spring and various arms, bushing, etc. Struts is part of the geometry so every time you change one out it will affect the geometry.

I personally would still do an alignment just to sleep better, regardless of struct or shocks.


The strut takes the place of the upper pivot point, which usually us an upper control arm or ball joint. The Honda hybrid suspension with the upper wishbone and a strut is different, but I would still align anyway.

 

[mclasser]

After I put in Quick Struts, my steering felt wonky. Got an alignment and the toe was off. I waited for the ride height to settle before going in.

If you're doing the work yourself, you're saving money anyway. Might as well get everything aligned for an optimal ride.

 

[slacktide_bitog]

Yes, you will need an alignment.

Once you undo the bottom bolts, you throw off the alignment.

 

[Audios]

Yes get the alignment after using it a few hundred miles so it settles.

 

[Oro_O]

Even changing JUST shocks in a front MacPherson strut suspension is very likely to through the alignment off. Definitely if doing the whole cartridge.

I did an experiment ~5 years ago to test this. I replaced the front shocks with OE units in the front of a Lexus ES. All other components unchanged. Since the tires were near the end of their life, I skipped the alignment to gauge the effect on tire wear as a proxy for alignment. Also, I measured as objectively as I could the ride height before and after the change, using a standard metal tape measure and noting height from ground to points on the fender arch, and also from the hub to the same points.

My measurements, within what I could tell with the tape eyeballing to the nearest 32nd, showed no change. But the tires started almost immediately wearing unevenly - they had been perfectly symmetric before that. So if you care at all about the tires, get the alignment. If they are near finished, you could eyeball the results and see. And sway bar components like bushings and link ends won't make a difference at all.

In another test, last year I replaced the lower control arms in the same car, complete with the lower bushings. I ran it for about six months until it needed new tires and there was zero change in handling or tire wear. I put on new tires without an alignment and they are wearing fine.

 

[WyrTwister]

How about the back ?

Did rear struts on one of our 1990's model GM cars . Never noticed any problem after that . No alignment .

 

[Nick1994]

Yes. The springs will sit at a different height, which will affect the toe in and out

 

[dlundblad]

Originally Posted by eljefino
If your strut holes are round, no. If they're oblong, yes.

Put the big huge bolts in finger tight, then shake your strut where it meets the knuckle. Moves in & out? You need aligning. No? You don't.

Same with the upper strut mount. If the holes are set up so you can wiggle it around, you need aligning.


I vote yes. The bolt holes on the knuckle and upper mount with the Volvo in my signature are round. After installing Sachs quick struts on the front, the ride height went up substantially.. Toe and camber were both off chart wise. Camber was visually off.

Obviously YMMV, but she drove around like that for a few weeks until we were able to get it aligned and it was clearly wearing down the outer edges of the tires.