I was reading my FSM and it seems possible to perform alignment w/o the rack. Besides accuracy/precision of laser targeting offered by The Rack, is DIY alignment plausible? Anybody have firsthand experience or anecdotal info?

Jae

 

I adjusted my toe after adjusting my coilovers. Its not hard, just time consuming by yourself because you have to do it, then test, do it, test, etc etc...

Jack it up, remove wheel. Loosen the nut on the tie rod end. Spin the rod in or out of the end mount. Tighten nut. Put wheel back on, and lower. Test drive, test measure. Repeat.

 

Yeah it is very time consuming, basically you jack up, adjust then drive, you will find you are doing this several times, i tried it and just said screw it after the first attempt. I just took it to the alighnment rack at work and adjusted it there. The adjustments are so fine tuned that it would be nearly impossible to get both sides equal (which is what you want). You must really understand how the suspension works before you adjust it, becuase theres toe in, toe out, +/- Camber, +/- caster, etcc. The rear is not adjustable, this is assuming you drive either a 4th/5th gen or any vehicle with the rear beam.

 

About 25 years worth of the former (using several different means of measuring the angles, none of which cost more than about $75 in equipment), plus a couple of general write-ups (that aren't on this computer).

With a good understanding of the alignment angles and what affects each, a little patience, and a flat setup area (preferably level, although you can work around non-level if it's a flat plane surface), you can work to within ±0.1° camber and toe.

I've never had to jack a car up to do an alignment - after making an adjustment or two, rolling the car straight forward a few feet and then back to where I took the measurements has always been enough to re-settle the suspension for checking purposes.

Norm

 

^+1. I got a great book called "Chassis Engineering" that gives a great, easy DIY for alignment. I don't know much on Maximas, but I aligned my G35 sedan after lowering it myself to save some $$$.

Just make sure the ground you are on is flat, and being level helps. You'll need a protractor level (Sears for ~$20 I think), a straight, 8' piece of square tubing (or a 2x4 works as well) and a couple of cans of the same height. Add a ruler and you're good to go. I strongly recommend that book - there's a lot of great insight on suspension geometry as well.

 

If you're lowered, its not easy to adjust stuff without the tire off...atleast not for me. Need a pit.... >.<

I also read that caster is not a big deal for our cars. Not sure where, but I think it talked about how its very hard to adjust, measure, etc...and doesnt have much effect if off, is this right?

 

Caster affects high speed stability, and it's not usually adjustable on OEM suspension. I'm not sure what the FWD suspension of a Maxima looks like, but usually there is an upper A-arm with a ball joint, and you will notice that ball joint is more likely to be located more towards the rear of the car rather than centered on the A-arm. This gives the car positive caster and better high speed stability.

Caster also has to do with the front wheel's angle during turns. If it is adjustable (I had aftermarket A-arms from SPL Parts on my G35 sedan), then the caster is measured (more or less estimated) by measuring the wheel's camber at full right, then full left and taking the difference of the two camber measurements. Then you have a pretty good estimate of your caster.

Yeah, self alignment in your garage is a LOT of trial and error. But it's well worth the feeling of accomplishment alone, in my opinion.

 

Not getting notices of replies to topic . . .

Caster is the slightly tricky one to measure, and the amount you steer the wheels is relatively important, as small differences in steer angle can be magnified in the caster computations. Pretty closely,

[caster] = [factor] * [camber with wheels steered one way] - [camber with wheels steered the same amount the other way]

where [factor] = 0.5 / [ sin(steer angle) ]

I welded up a jig with a 14.5° / 165.5° included angles as a reference for the steering and use 2.0 as my factor. Better than guessing, not as good as turn plates marked with a degrees scale.


As to working on a lowered car, driving it up on a couple of lengths per side of 2 x 10 or 2 x 12 chosen as carefully as possible for flatness ought to be good enough get you pretty close. While it's really nice to work at waist height if you did this sort of thing all day long, a few inches clearance is usually enough for once in a while.


Norm

 

I use a tape measure for the toe by measuring the distance from the front of the two tires and the rear of the front tires. If measure is equal then the toe is at 0 degree. As for camber since I have camber kit's and it's adjustable I have a level guage that sticks to my wheels. Always do camber first.

Caster=no adjustment on our rides so who cares

 

That's about the only way I haven't used to measure toe. It's much more reliable to work from the wheel flanges, which don't have any little bumps, raised lettering, or other unevenness to throw the measurements off. Unless the wheel flanges are damaged, in which case you're unlikely to get a good result regardless of the method used. You either calculate toe as an angle or scale the difference in measurements up to what they'd be at the tire OD (which you should be doing if you are measuring to the widest point of the sidewall instead of to the edge of the tread).

Maybe caster isn't adjustable with OE methods, or adjustable as far as you might want to push it. But it can be changed if you really want to change it.


Norm