Front End Alignment

[1993Saturn]

I have a '94 4WD and need to get a front end alignment. Is there no adjustability to the rear axle and therefore spending for a 4-wheel alignment is money down a fool's hole?

 

[IZwack]

That is correct - there is no adjustment possible for the rear axle.

 

[corkey]

there is no adjustment on the back, but a 4 wheel alignment also makes sure the truck is tracking straight, and not going up the road sideways,, usually called crab walking,,

if it is crab walking it could be bent,,

 

[1993Saturn]

So the rear axle not being adjustable, the 4-wheel alignment is just a laser measurement or whatever to insure the rear is square with the front. THen if it isn't the shop will tell you the front is aligned but the rear ain't so you are screwed...that will be $60 please? Heh, go down fighting, right?

 

[corkey]

no, if it is not square there are things that can be done,, caster can take out some of the crab walk by moving the wheels foreward or backwards a few degrees effectively making the truck track straight and not pull to the left or right,, and if they say they can't do anything about it they shouldn't be doing alignments, cause they don't actually know what they are doing,,
http://www.amdtechnik.com/technical.4wheelalignment.cfm

 

[1993Saturn]

Nice link you placed there to AmD Technik. Rather informative. In looking at the questions you need to ask a shop, I would like to understand some of the terminologies:

"1)Does the equipment allow for any road wheel run-out?
It is common for road wheels to have up to a 3mm 'buckle' in the wheel. Therefore if the equipment is not able to compensate for such run-out.."
So what then is run-out and buckle.

"4) Does your equipment check all the road wheels?
If the equipment does not- you are wasting your time and your money." Does this mean do they check all 4 rims for those problems, even though they are doing just a front alignment only?

AND, I understand the rear axle spaces out the rear tires about 3" more than the front tires, so when following behind, it can appear to have an axis deviation, when in fact it doesn't.

 

[corkey]

runout,and buckle,,--- sidewall flex, and the amount of it, runout also gives possibly the camber of the back wheel,

check road wheels,--- on some machines, they can find out if a rim is bent,,

 

[1993Saturn]

Thank You corkey for your information. Now I will be informed when I get the job done this next Saturday.