So we just bought this 55 chevy wagon, and to tell you the truth it drives like a soup sandwich on any surface that isn't perfectly flat(road crown, pavement ruts, ect) I threw it up on the alignment rack to see what was going on everything is tight including ball joints, cross shaft bushings, steering linkages, and steering gear. I checked the alignment and there was almost no caster which is what the spec called for and it had a little positive camber. I reset the alignment to 2.5 degrees of positive caster and a half of a degree of negative camber, then reset the toe. Now it drives a little better but not all that great. so I dove in a little closer and noticed that the scrub radius is clear on the inside of the tires, it has 0 offset wheels which I bet it had from the factory(although they are a little wider) Yes I could go with a wheel that had a lot more back space but the wheels look good in the fenders as they are. I have done a bit of searching here and google and not really coming up with much that discusses this. there are a lot of replacement spindles and control arms that are meant to work with stock parts so you know the problem has not been addressed. Does anyone know of a later model spindle and control arm swap that would help with this issue?(maybe monte carlo, or chevelle or something) I would like to find something that doesn't require extensive frame modification as we are using the car as a daily at this point and don't want the car down for a long period.
While it does have the standard body roll issue, I'm more after the "Herding it in a strait line" problem. All of the front suspension seems to have a recent rebuild. I'm positive that moving the centerline of the wheels in would make it drive a ton better, I just like how the wheels look in the wheelwell now.
To improve the scrub radius issue, you need to move the tire's centerline closer to the center of the car. If you want to retain the clearance that you have between the tire and the fender, then the solution is to get wider rims (and tires) with a backspacing to get to the desired track width.
My 56 was one of the best performing cars I have owned. As a previous posted said. "Try different tires"
VoodooTwin is right you'll have to go to wider rims with more backspacing is the best way or add more caster but it will make it steer heavier and will not address the scrub issue
I'm not sure about your reference to the scrub radius location. The above pic shows you how to measure it. It isn't a location it's a measurement. Can you elaborate?
Just a thought. You did note the idle is in good shape. Those are good driving and forgiving old cars. Wheel bearing in good shape?
I've had tons of 55-57 chevies in my lifetime and never ran across this sort of problem Radials always improves those cars but I ran bias plies way back when and they were fine. Try a tad more caster. Charlie
Try bumping the caster to a degree , degree and a half . When your at less than a 1/2 degree the steering will have almost no feel .
A taller tire will help. Of course you will have to decide if thats possible or not. I added a scrap yard sway bar to a friends 57 a few years ago...along with making up a disc brake setup for it. He said they were the two best modifications he ever had done to the car. NOW he can drive it hard and actually enjoy it! No idea what the bar was out of, but he found something that fit just by going to the scrapyard, armed with a few measurements and a tape. I made the brackets and installed it for him.
I think you guys are right on the money with the tire issue as I'm sure the factory tire had a high side wall tire and the wheel may have had more backspacing. What I have now is a wider than stock(i think 7" wide) 15 " wheel, with fairly wide radial tires with a low aspect ratio(60 series). The factory setup probably works well with a factory tire and wheel setup, but I'm liking the look I have now and would like to switch to a spindle/a-arm setup that had a more angled steering axis to move the scrub radius outward to work well with my wheel/tire combo. Working well while looking cool isn't alway easy!...or cheap.
Getting tapered roller bearing hubs will help a lot. The original ball bearings allowed the hub/wheel to move around. ~Alden