newheeler

This may be a dumb question...

I'm on the fence as to whether or not I’m going to install some new coil overs (probably SAWs) myself ('03 Tacoma). I found some pretty good, detailed instructions on the web and it doesn't seem that difficult. But while I am mechanically inclined, I really don’t do much auto work beyond fluids.

That said, it seems like a lot of people recommend getting an alignment after installing the new coil overs. Ok, fine...

I have no idea how vehicle alignment works at all. How badly can (or does) the alignment get out of whack when putting on new coil overs?

Or, what's the mechanical relationship between the coil over assembly and whatever controls vehicle alignment?

Just peering underneath it seems like the coil over assembly has two fixed points – 3 mounting bolts on top and 1 bolt on the lower shock eye. If the new shock assembly attaches to the same 2 fixed points, how does this relate to the alignment?

Thanks in advance for the clarification.

Good Times

I'm no expert myself but the suspension indirectly affects the alignment. Just like how the tire affects the alignment, if the suspension is out of whack, it can affect the alignment as well

Therefore, whenever you do any suspension work, it is wise to get an alignment. Always good to be safe than sorry.

keisur

if the new assembly is longer or shorter than the current one then the alignment will be out of whack after the install of the new stuff. the alignment is basically adjusted by the two eccentric bolts on the lower a-arm (camber) and the inner tierod/outter tierod connection (toe). then the length of the coilover changes, the camber becomes negative (top of tire leaning in, indicative of a shorter coilover causing a lowering of the front end) or positive (top of tire leaning out, indicative of a longer coilover causing a lifting of the front end) and the toe may also get out of spec. like GT said, get an alignment, better so be safe, even if it feels ok. Also there is a caster angle which I won't bother getting into, basically it's the angle the knuckle is making front to back with respect to the vertical. that ones really hard to explain without a good diagram.

hope that clarifies.

nightsurfride

Caster is the relation of the upper ball joint to the lower ball joint forward or rearward of the vehicle. It is a non tire wearing angle. It directly effects how straight the vehicle drives down the road. The upper ball joint being more forward then the lower is more neg. caster. The upper ball joint being rearward of the lower ball joint is more pos, caster. Typically most vehicles will pull to the side with more neg. caster. (usually .7 deg. or more difference)

newheeler

Thanks a lot! That makes sense to me.

waskillywabbit

iTrader: (-1)

I am very disappointed that there was no Free Body Diagram provided.

mt_goat

Yes, we want free body diagrams!

keisur

AW jeez.