The Ford Barn

700rpm · 02-06-2012, 12:29 PM

My coupe kind of hops as I accelerate up to about 25. Then it smooths out. And when I decelerate it hops again. It's like it has a bent wheel or axle, but I've had a friend watch from behind as I drive it, and he says it appears to ride smoothly.

The front seems solid; there's no shimmy. It really feels like it's coming from the back, but I don't know how to accurately analyze this. Any suggestions?

Patrick L. · 02-06-2012, 01:13 PM

What kind of tires?? Kinda sounds as if you may have a bad tire if the 'hop' doesn't go away.. If it disappears after the tires have warmed up a bit you probably have nylon or rayon belted tires..

Clem Clement · 02-06-2012, 01:28 PM

Jack up the rear safely. then with lots of safety run the car with someone watching the wheels. you may have a budging tire. Be safe with this maneuver. No cheesy jacks, please.
You could swap tires to the front and spin them to check. Also if you car sets a spell sometires develop a flat-side set.

I had a shaker that turned out to be a badly out of balance rim.

700rpm · 02-06-2012, 07:05 PM

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What I learned: This afternoon I jacked up the car and removed the rear wheels and watched the hubs for wobble. There was some. I took the hubs off and checked the axle for wobble; there was some but not as much. I attributed this to the floating axle effect. I noticed the hubs were not adequately torqued down, the keys were loose and it has axle shims, which I don't like.

I peened the keyways down till the keys sat snug; put the shims back in anyway; greased the bearings; torqued the hubs properly; and rotated the tires (while I had half of them off, may as well do it). I adjusted the brakes and took it out for a trial. It's hard to tell on a bouncy ol' Model A, but the hopping seems to have been significantly reduced, if not eliminated altogether. In any case, it is a great improvement and I think I can live with it.

I hope some other guys can benefit from this experience if they are having a similar problem.

02-06-2012, 12:29 PM	#1
700rpm Senior Member Join Date: May 2010 Location: Portland, Oregon Posts: 5,906	Hopalong: Update: What I learned My coupe kind of hops as I accelerate up to about 25. Then it smooths out. And when I decelerate it hops again. It's like it has a bent wheel or axle, but I've had a friend watch from behind as I drive it, and he says it appears to ride smoothly. The front seems solid; there's no shimmy. It really feels like it's coming from the back, but I don't know how to accurately analyze this. Any suggestions? __________________ Ray Horton, Portland, OR As you go through life, keep your eye on the donut, not the hole. Last edited by 700rpm; 02-06-2012 at 06:57 PM.

02-06-2012, 01:13 PM	#2
Patrick L. Senior Member Join Date: May 2010 Location: Largo Florida Posts: 7,225	Re: Hopalong What kind of tires?? Kinda sounds as if you may have a bad tire if the 'hop' doesn't go away.. If it disappears after the tires have warmed up a bit you probably have nylon or rayon belted tires..

02-06-2012, 01:28 PM	#3
Clem Clement Senior Member Join Date: May 2010 Location: Fairfax, VA Posts: 3,393	Re: Hopalong Jack up the rear safely. then with lots of safety run the car with someone watching the wheels. you may have a budging tire. Be safe with this maneuver. No cheesy jacks, please. You could swap tires to the front and spin them to check. Also if you car sets a spell sometires develop a flat-side set. I had a shaker that turned out to be a badly out of balance rim.

02-06-2012, 07:05 PM	#4
700rpm Senior Member Join Date: May 2010 Location: Portland, Oregon Posts: 5,906	Re: Hopalong: Update: What I learned Sponsored Links (Register now to hide all advertisements) What I learned: This afternoon I jacked up the car and removed the rear wheels and watched the hubs for wobble. There was some. I took the hubs off and checked the axle for wobble; there was some but not as much. I attributed this to the floating axle effect. I noticed the hubs were not adequately torqued down, the keys were loose and it has axle shims, which I don't like. I peened the keyways down till the keys sat snug; put the shims back in anyway; greased the bearings; torqued the hubs properly; and rotated the tires (while I had half of them off, may as well do it). I adjusted the brakes and took it out for a trial. It's hard to tell on a bouncy ol' Model A, but the hopping seems to have been significantly reduced, if not eliminated altogether. In any case, it is a great improvement and I think I can live with it. I hope some other guys can benefit from this experience if they are having a similar problem. __________________ Ray Horton, Portland, OR As you go through life, keep your eye on the donut, not the hole.