Ok here's the question.... a pal has a model A rod with a dropped I beam , not sure of the mfg, could be a Super Bell ?? Anyhow hits the road and 'bout 40/ 50 mph one wheel starts to bounce and then goes across the axle. Now we are really bouncing. Doesn't go away if you go faster. He is running early Ford wire wheels with new tires. Both wheels are balanced . We thot maybe the shock angle was off 'cause they were more laying down than on a decent angle. So changed that. Still no change. Caster and toe in are on , hairpin wishbones are from the usual mfgs. Any suggestions where to look next? In my way of thinking this would happen if the wheels were out of balance or the shocks weren't working ! I'm stumped !
Make sure the tires are not out of round or the wheels have any runout first. Also check to see that your drums are not out of balance. Butch
Lots of stuff causes it, look for worn kingpins, not enough caster ( I use 6-9 degrees) offset wheels, funky tires (are you running bias plys?) not enough toe in (1/16-1/8 works for me) too soft front shocks and sloppy steering are prime causes.
Start with the simple things, check alignment first, condition of tires, balance and roundness of the tires.
Thanx for the input.... alignment is on , caster, camber an' toein, wheels an tires have been balanced, shocks are new, tried another set of balanced steel wheels same damn thing. King pins seem tight . I'm stuck.. in all my years hot roddin' haven't hit a problem like this that can't be solved! Anybody else???
might be under-dampened. If it can move that far, that fast, you have an issue with dampening. big difference between race car shocks and passenger car shocks as it pertains to compression and rebound. That said, there is another issue, why does it start hopping? It's possible you have an issue with bump steer setting it off. Perhaps there is an issue with draglink and it's steering the car when the suspension moves, setting it off. Do you have a panhard? front end can "swing-set" (my term) a bit without one.
question 1 did it just start doing this? what has changes since it started doing this? if the car has been put together for some time and no parts have been changed ( wheels tires ) then some thing else is worn.
shocks too soft.....My buddies sedan did that as I drove it to GG Columbus last year. He was running friction shocks...It might need a steering dampner as well...
Are the tires out of round? Jack up the front axle so the tires are off the ground. Use a fixed object, like a jack stand with a board fastened to it, placed close to the tread. Spin the tire slowly by hand and see if the tire is out of round.
hold on, stop chasing zebras put a different set of tires on the thing and see if it does it then at least you'll be narrowing it down
He already tried to switch wheels guys...read a little deeper. Things to check that haven't been listed; spindle nut debris behind brake hat against hub (haven't mentioned if you have disc or drum) broken or weak spring in drum brake setup (allows things to start moving within drum accentuated by any slight imbalance and snowballs) I'd also check the shocks like others have mentioned.
spend the money and have the tires trued or shaved. Most shops that offer this service will also balance your drums with the rims and tires while it's on your vehicle, you won't have the wheel hoppin' anymore. It sucks that you have to do this, even with new tires. That's what happens when big manufactures put out such shitty quality tires like Firestone, 16 inch bias ply's- notorious for out of round tires. Just my 2cents.
the ford wires require a center align disk because the wheels are lug centric not hub centric like most vehicles this would definately cause this prob also a flat spot on the tire from sitting,bias ply tires a more susceptable to this verses radial because of their construction
Has the frame been boxed in? Are the cross members beefed up? Your shocks might just be flexing the frame instead if dampening. Or it could be tire scrub because the front is not square with the rear.
I'm having the same problem on my 32. It's been doing that for 25 years according to the previous owner, who got it to a place he could drive through it. Mine starts at 45, ends about 52, and two owners, including hot rod pros, have been through everything on it. I added a few lbs to the tire pressure and it helped, but didn't cure it. That was after weeks of parts changing, adjusting, and wrenching. It may be a chassis characteristic, because something creates a harmonic vibration that sets it off. Toe in adjustment may help (move it all over and try it) too. Sounds like everything is right but it's not working. I know the feeling.
I work at a collision center. we run into this often. that would be my best guess without seeing the car in person
A little more information is needed to whittle down the list of possible culprits: Is this a new build? If no and the car behaved well previously, what was changed? Wheels? Wheels and tires? Brakes, drum to disc, none to drums, none to discs? If yes: Shocks laying down? What does that mean? Front to back, side to side? What steering box? Cross-steering or fore-aft drag link steering?
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