The Stovebolt Site Forums The Shop Area Driveline Why does my truck wander going down the road???

Just wondering why for the five years I've been on Stovebolt and trying to figure out why my truck wanders on the road. I always thought it was possibly because it had to do with a steering box issue. When it actually was a problem with a caster shims issue instead. Well if your truck doesn't have them under your front leaf springs and no one tells you they should be there. Because they are supposed to be there per the parts listed for your truck. How would I know to ask about them.

I wish someone would have said, so your truck wanders down the road. You should check to see if your caster shims are under your front leaf springs. I would have said, nope there aren't any.
It would have solved a lot of white knuckling rides down the road.

Sorry, this wasn't supposed to sound like a rant. I'm not upset. I'm just happy to have stumbled on the information I needed.

Elmo

Unfortunately, the days of getting anything resembling a correct wheel alignment on these old rigs are long gone, along with the people who actually understood steering and suspension geometry. My grandson is the exception that proves the rule, but only because an old geezer sat him down for a few hours and pounded the knowledge into his head. Every now and then, he calls me to consult on a difficult alignment, and we usually figure out that the problem is a short circuit between the steering wheel and the brake pedal- - - - -a vehicle owner who thinks he can install the latest fad going - - - -tires and wheels too big- - - -too small- - - -too narrow- - - -too wide, and/or they hang out of the fenders so far that the truck needs a "wide load" sign! That's when the flat rate labor goes out the window, and the job gets charged out at a "straight labor time plus materials" rate!
Jerry

I just took Bessie in for an alignment to the only shop in a town of 200,000 people who said they could do it. They have been in business here for 50+ years and are known as the brake, suspension and wheel experts. They called to tell me it was all done. They set the toe-in and lubed it up. When I asked about the caster the reply was "I don't know, I am sure he checked it though". Turns out he did not check it. 4 hours later I was told it drives the straightest is has today. I did not dare ask about camber. I paid the requested 240.00 and got the heck out of there. When I got to 50MPH on the highway, I darn near soiled myself and took the first exit. Back roads and 40MPH and it does feel good. Thinking I should bring it to your grandson Jerry.

For what it is worth, your shop manual tells you the caster ought to be a max of around 2.25 degrees. Over the past 55 years of messing with these, I've learned they actually handle best if the caster is between 2.5 and 3 degrees. And one half of a degree does make a notable difference. However...please keep in mind there is a trade-off. The greater your caster angle is, the straighter your truck will run down the road. Also, please keep in mind the greater your caster angle is, the harder your truck will be to steer (in town, especially). The reason is because the caster angle means all the weight of your front end sits on top of an angle and when you turn your wheels, you're actually lifting the truck up. So there is a trade-off...2 or 2.25 degrees is okay. It means your truck will steer easily and will be reasonably straight while driving down the road. And remember...these trucks were designed to be driven between 50 and 60 mph. Little or no caster angle means your truck will steer easier and also will wander around like a drunk billy goat.

Ardmore Alabama is approximately 2500 miles east of you, but it would be worth the trip to visit America. We won't even get into the procedure of twisting the axle so there's approximately 1/2 degree difference in caster side to side- - - - -to correct for road crown. The passenger's side needs to have a slightly more positive caster than the driver's side, but the fixtures needed to twist that axle between the spring pad and the spindle probably got scrapped a few decades ago.
Jerry

Just an up date. I finally got a chance to go down the road with the 3 degree caster shims I installed in my front leaf spring pack. No more white knuckling it down the road.
I replaced the front shackles, leaf springs, U bolts and added the 3 degree caster shims. My king pins were replaced 3 years ago. Now I am enjoying driving the truck.
Elmo


I have a 1953 Chevrolet 3600.

Elmo - Thats excellent news! Glad to hear your problems got resolved and you're enjoying a non-white knuckle driving experience - LOL!

Great to hear to on a straight and narrow path down the road. Thanks for posting results, I've filed them away for future reference.

Satisfaction when you do it yourself! Glad it came out good!