model a shakes

I need help I have a 1930 model a. Model a frame boxed from front cross member back. Split wishbones, dropped I-beam standard eye spring. I'm running 16" ford steel wheels with 5.50x16 repo bias ply tires. When driving above 55 mph the sterring starts to shake. I know there is no side to side support with this type of set up, but should it shake so much? Any ideas to cure this problem?

 

what tire pressure and hows your toe-in, etc. what type of steering setup do you have?

 

is the alignment correct? what type of shocks? tires balanced? those things will cause probs.

 

Almost without doubt I'd say it's the tires. I've had a couple of cars I have tried everything to eliminate that problem, but its the tires. The Firestone Delux Champs seem to be the worst and they vary set to set. The dirt trackers seem to be better. A lot of folks recomend having them shaved to make 'em round. Tire balance dosn't seem to have much effect, I think its the slightly out of round combined with stiff sidewalls.

Borrow a set of radials and stick them up front and I'll bet the problem goes away.

 

sounds like a danger, better ship it up to me to be safe

back on point, tires sound like your issue, my daily driver Volvo is currently experiencing the same thing.

 

Wasn't there a whole thread on Coker Firestone tires being the problem of the shakes????
Try to search it, you'll find it!!
I had the same problem with my Firestones, but it's gotten a whole lot better, I guess they broke-in like a nice pair of shoes!!!

 

Had a similar problem with 35 Inch Mud tires. they went out of round and no amount of rebalancing fixed teh situation. Are you storing the thing in the air with minimal tire pressure in them during the off season? The truck tires did it with daily driving, but it gets worse when you store stuff for long periods.

 

i'll second that... mine start to bounce above 65...

 

I've heard old timers say they tried and tried to fix a high speed shaking problem, and when they put a new spring on the front end, the driveability improved greatly.

 

Have the tires shaved - they spin the tires on the car and see if they wobble. Balance the tire with the hub and drum attached. Perhaps a lil toe-in. If all else fails, put a steering dampner on it. Improved the ride so much I swear by them.

I just put a new spring up front and didnt notice much difference in shake, but the ride improved dramatically. my wheel still hops above 65 mph, though and im thinking I should shave my tires too.

 

There are two types of oscillation, shake and shimmy. Shake is an up-and-down motion caused by tire roundness (or lack thereof) and/or balance.

Shimmy is a side-to-side motion, and was real common on older cars, especially buggy sprung suspensions. There are a couple of ways of getting rid of shimmy:

1) make sure your kingpins and bushing are fresh and tight.
2) Increase caster angle. This can cure the shakies but at the cost of increased off-center effort.
3) The track racers of the day cured the shimmies by welding the spring shackle on one side to positively locate the front end.

 

Does the front end have a panhard bar and are you sure it's a shake?

 

Aint it neat we just gotta have it old school .........the way that ws corrected was the advancement of radial tires and gas shocks but by god that aint traditional... funny how that **** works aint it............I agree get em spun and shaved or switch tires and have the old wheels checked without the tires on them as well.. and make sure that there is not any slack anywhere in your steering set up box, etc...

 

Make sure all bushings are good, spring shock, etc. Check tire pressure, lower tire pressure.

 

Had same problem with similar setup. New tires fixed my problem.

 

The Coker tire syndrome?

 

Check Your Toe In!!!!