I have a new vega box on the cross steer on my straight axle 34 truck. Before alignment it had quite a bit of wander. It has bias plys and when running on a road with grooves from heavy truck traffic it would be all over the road. I just got it back from the alignment shop after installing a new axle. It helped it quite a bit but still has some wander to it. Would slightly increasing or decreasing the toe in or out help? An suggestions? The steering linkages are all tight. PJ
If the truck highway grooves are as big as some I've seen in Sunny California I'm not surprised. Caster strikes me as being of interest here. Are you running enough? 5-6 degrees seems to work well for most hot rods. If you're at 5-6 degrees was it measured against a flat floor surface? Reason I ask is I've seen caster set using the flat part of the frame rails as a reference and heard others talk about doing it that way. If the alignment shop checked the caster and found it ok, more then likely they're right, but it wouldn't hurt to check it yourself. Got another pair of front tires you could try? Bias or radial, just something to eliminate the tires from the equation. Another thought is, is steering wheel play minimal? Steering box adjusted properly? Some types of aftermarket steering u-joints wear fairly quick. Borgeson and Flaming River are a couple of brands that are long lasting. The original u-joints on my 32 - Deuce Factory, but they handle a different brand now - went away pretty fast and I was surprised how much u-joint play there was compared to the new Borgesons that were installed. If everything checks out ok and caster is at 5-6 degrees, I'd dial in a couple more degrees and see how it works out. About 8 degrees should be the max, any more than that and additional steering effort output - from the driver -will be required.
You didn't say how much you have now. I had an experience where too much toe in caused it to want to wander. Too much toe in and the tire that is getting the most traction (not scuffing as much) will direct the car in the way it is pointing. If the other tire starts to scuff less, it will want to head back the other way. We'd get a lot of people complaining about wandering until we aired up their tires. If you are running lower air pressures for a smoother ride, the tires can squirm causing you to react with the steering wheel...especially the rear tires. (I see guys running, what I think is, way too low air pressure just to get a softer ride) You are constantly correcting the front wheels to compensate for the wishy washy rear tires. We aired up their tires and the perceived wandering disappeared. It's easy to check and experiment with and doesn't cost anything. See what toe in you are running now. Try a little less and see what happens. Experiment to see what your combination likes. Most of the front end specs that we take from the manuals for our old hot rods were for cars of different weights that ran different sized tires. That a good place to start, but it may take a little dialing in.
Thanks C9 ! The Borgeson steering U-joints are all new. The Vega box is new. The steering arms all fit tightly. Is there a way to adjust the vega box? It seems tight but was just wondering. This is a good alignment shop using a Hunter. I'll check the Caster and see where its at and go from there. The truck grooves are horrendous here. Pothole city too. My rear tires are running 30 pounds. I'll then try the toe out as Tommy suggests.
I may just do that ****. If all else fails. We are spoiled with our everyday driver IFS setups with radials.
I second and third suggestions on tires...bias tires now are seriously non-mainstream, which means they are made by small, funky operations and may have distorted carc***es, out of round conditions, etc. You could even just swap them side for side and see if problem changes a bit... And when the hell did the HAMB get a spell checker...that doesn't recognize "HAMB" as a proper word??
Adjusting Vega box instuctions are in Motor's Manuals. Maybe in Chiltons as well, but I like Motor's Manual better. If the steering box seems ok now, it probably is. Maybe I missed it, but Tommy was talking about toe-in I believe. Toe-out is a trick done by ol timey alignment shops to calm down a worn solid axle suspension. About 3/32" - 1/8" or so toe-out if necessary, but it looks like you don't need toe-out. No panhard bar? Like ****ster27 says, install one. A home-made panhard bar is easy. You can get the polyurethane bushings in the sizes - and colors - needed from Energy Suspension. The rest is made from DOM tubing for the rings and bar, a headless Grade 8 bolt and jam nut. (Jam nuts are the thin ones used for locking the adjustment in place.) Looking back to when my 32 had excessive steering wheel play due to the worn u-joints it still handled ok and didn't wander. Probably due to the panhard bar that went in as part of the initial build. The car drives and handles well. It does have radials, but lots of guys run bias and have no problems. 6 degrees caster and 3/32" toe-in. Kerry - of blown Hemi, 31 Pontiac coupe fame - has driven the 32 and if he happens to stop in here I'm sure he'll agree with how well the 32 does drive.
Yes I was talking about experimenting with different amounts of toe in. I'd never suggest toe out for anything. I also believe that with bias plys there will be some conflict with rutted roads that radials seem to absorb. My roadster with bias plys runs straight and true but it does pick up the ruts more than my coupe with the radials. It's not dangerous but noticeable. A compromise I choose to make for the looks.
I would put on a deadman or a panhard bar and I feel it will solve most of your problem if not all. With a Vega box set-up it has to push and pull and will tend to shift the ch***ie a bit before moving the tire.. When your sitting still and you turn the wheel does it move the ch***ie first?? before the wheels turn??
Hmmm. dont know.. I'll check that out. I havent had a bumpsteer so i figured a panhard wouldnt be needed. looks like I was wrong. I too hate to go with radials on the years earlier than 35.
do you have the vega box clocked right , meaning the piman arm centered to the worm gear. when centered there should be no left to right movement of the pitman arm, move it to the left or right than there will be a few thousands of play in the box , is easy to get them a 1/4 to a 1/2 turn off. also a panhard bar i won't even think about not running one.
You know if the ch***ie is all done and you don't want to mess with the panhard bar just use the Deadman. The Deuce factory is the one I use and love it.. I have wondered if anyone else make one??
Thanks Dave for the tip! I have never heard of this issue with Vega boxes. Of couse this is my first one. I just installed it and measured my center by counting the number of turns to the left and to the right. The reason i did that was to be sure I had enough travel in both directions. By this..the center may not necessarily be at this position and I could very well have some initial play in there before making my turns.
Wow, a couple of things here. 1. Don't toe it out, as Tommy already said, the biggest contributer to wander that I know of is toe out, about 1/16th to 1/8th" total toe in is fine for tire wear and straight running, toe is the worst angle for tire wear, so if you get excessive either way it will rip the the edges off the tires. 2. I don't believe a steering damper is going to do anything to alleviate your problem, they are designed to eliminate high frequency shimmy, usually on poorly engineered front ends and do very little or nothing to cure wander, if your front end is right it shouldn't need one. 3. 5 to 7 degrees of castor is not, and never will be necesary at normal highway speeds, the car should drive straight and nice at 2 to 3 degrees, and actually steer well at parking lot speeds. If your going full out at Bonneville thats another story. I just had a friends 37 plymouth rod with independent on my alignment rack Friday, and set at 1.5 degrees castor ( I wanted a little more but coudn't get it) it went down the road at 75 like an arrow. 4. Did the allignment shop mention what the rear thrust was on the car, a slight amount can be compensated for with allignment, maybe a tenth or two, but if the rear is way out of square it will continually steer the car and you continually need to compensate with the wheel to keep it straight, instant wander. 5. Byas ply tires are well known for there tendency to follow pavement irregularities, it's the nature of the beast, so if you want that Trad look you pretty much have to live with that, Its why radials virtually took over the market once people got a taste of them. Just some opinions from a a guy thats been alligning cars for a living for 40 some years.
The Jalopy Journal
