DIY caster adjustment possible?

[AC439]

I read the DIY alignment thread and also search the forum. I apologize if this has been discussed before but I couldn't find an answer.

I have been successfully doing toe and camber (on another adjustable car). But I want to check/adjust caster on my Accord. I know the radius rod can be adjusted for caster. However, I don't want to shoot in the dark. I'd like to be able to make some sensible and logical measurements before I start messing around with the radius rod. Is it possible to do DIY caster measurement? Is yes, how? Thanks. - AC

[AZmike]

This page describes how caster can be found by measuring how much camber changes as the steering is moved off center:
http://www.racerpartswholesale.com/pdfs/9500.pdf

The downside of adding caster using only the fastory adjustments is that you reduce negative camber at the same time.

[Oldblueaccord]

I's that true on our cars as well Mike? or more does it reduce negative EDIT: camber when the wheels are straight, when there turned, or compressed like in to a corner is I guess what I' m asking.


wp

[AZmike]

I'm not sure what you're asking so I'll try to be more specific and hopefully answer your question.

From the factory our Accords only allow caster and front and rear toe adjustment. On the 3rd generation Accord caster is adjusted by changing the length of the radius rod. Shortening the rod increases caster, but since it is angled inward, shortening the rod also pulls the lower balljoint inward somewhat. This inward movement reduces static (wheels steered straight ahead, suspension at regular ride height) negative camber. The additional caster adds back some of this helpful camber as the steering is moved off center. Adding a camber adjustment (like the prelude control arms) allows caster to be set higher and keep a reasonable amount of static negative camber.

Does that help?

[Oldblueaccord]

Yep that got it perfectly.


wp

[AC439]

Thanks for the info. I start to wonder if the bushings on my radius rods are old and worn out so that they may have changed the caster? But when I did the basic front suspension check, there are not noticable front/back play. How do I check the bushings on the radius rods? Or I might as well replace them since they are probably original (at least they have not been changed since I own the car for the last 130k miles)?

Also, How much does the camber gauge cost? Thanks.

[AZmike]

The radius rod compresses those bushings so you're not likely to ever get much play there. Most people notice an improvement when they replace their radius rod bushings, but I don't have any first-hand experience.

If you shim all four tires to be level +/- 1/8" or less a household level held vertically will work reasonably well. The tool referenced above is $40. As long as your car doesn't have wheels greater than 15" in diameter it should work well. I plan to get one before my next alignment. With that tool and a properly layed-out string setup you could do your own alignments very accurately.

[AC439]

Yes, I have been doing camber with a household level since my garage floor is very flat and level. I'm more interested in doing caster on the Honda because the car doesn't seem to return to center as good as before. The steering seems light too so I think the caster may be out (not enough positive caster). I think I may start messing around with adjusting (shorten) the radius rods 1/4 turn at a time both sides equally to see if I can fix this problem. I'd definitely mark the original positions of the nuts before I start. Any comments?

[AZmike]

1/4 turn is a very small change. I'd be temped to shorten both sides equally until one was at it's shortest. Mine is set that way with 2.2 degrees on both sides and I'm pleased with the result.

[AC439]

Thanks a bunch ! I'll try that. - AC