re-alignment after rear height adjustment

[86zn6]

I recently have the whiteline rear subframe bushes installed and notice the rear ride height increase a bit, like 5mm. I want to lower the rear height from my coilover by 5mm. Do I need alignment at all given the rear camber is not adjustable for our car?

[churchx]

Obviously, every time one unbolts/tightens something in suspension more then probably alignment gets out of whack and realignment is needed (including those bushes install). Unadjustable camber with stock LCAs aside, there is toe. Toe settings out of whack can introduce lot of handling issues/artifacts. Only time when you don't need alignment is changing wheels.

[strat61caster]

Lowering the rear by 5mm will introduce a very slight amount of toe in, for a Street driven car you should be fine to not go to a shop imho.

[Tcoat]

Originally Posted by strat61caster

Lowering the rear by 5mm will introduce a very slight amount of toe in, for a Street driven car you should be fine to not go to a shop imho.

Not just the end result that can impact it but also the process of getting it there. Some can eyeball it but it is best to have it done properly.

[strat61caster]

You don't have to touch the alignment at all when moving the spring perches a modest amount evenly, the impacts are negligible to daily drivers.

Edit: looked at my notes, going from 26" top of fender arch down to 24.4" top of fender arch introduced a whopping 1mm of toe in for the rear. OP is probably moving his 5mm within that range and won't notice much of a difference.

[churchx]

There is chance that some part upgrades change alignment evenly .. but there still is problem of some play/slack is in most connections, and unbolting/retightening to install/change those parts that by themselves should be changing "evenly", also can fsck up alignment at extremes of that play. I had some alignment caused handling issues in past, fixed by realignment, later had desired handling changes on track, via alignment .. in my book/experience importance of proper alignment in car that is "driver's car" is placed high enough and imho not worth slight savings by not doing. If anything, uneven tire wear and due that spent more money on tires can offset alignment job costs, even if not valuing in money satisfaction of properly running car not needing any driver input workarounds.

[strat61caster]

Y'all clearly don't adjust your own ride heights...

[Turdinator]

As mentioned above, for 5mm drop you could get by without an alignment. That said if you changed subframe bushes chances are the alignment of the rear subframe changed also. If it were me, I would get an alignment. They are cheap and will give you peace of mind.

[strat61caster]

Originally Posted by Turdinator

As mentioned above, for 5mm drop you could get by without an alignment. That said if you changed subframe bushes chances are the alignment of the rear subframe changed also. If it were me, I would get an alignment. They are cheap and will give you peace of mind.

All the suspension arms connect to the subframe, you will not affect individual wheel alignment by messing with the subframe. You may shift the subframe in the car slightly, but the only way to correct that is for the shop to readjust the subframe and most are too lazy to do that properly.

[Turdinator]

Originally Posted by strat61caster

All the suspension arms connect to the subframe, you will not affect individual wheel alignment by messing with the subframe. You may shift the subframe in the car slightly, but the only way to correct that is for the shop to readjust the subframe and most are too lazy to do that properly.

Yeah I imagine most places wouldn't. Using the toe adjust to correct it would be better than nothing tho. Unless alignments are expensive there I'd just do it. Here in Melbourne Australia i can get a good alignment done for $80.