vibration

I have a vibration that you can also hear in my 1963 ford fairlane 500 sports coupe. Car vibrates at all speeds when accilerating and also coasting. also when coasting with engine idling and car in neutral. All the following has been done, Changed front wheel bearings,rear wheel bearings u-joints,the whole driveshaft,all 4 tires and also balanced,rear shocks. Transmission checked by specialists. Engine mounts checked,flex plate, converter too. Bear in mind that the vibration is still prominent when coasting down a hill while in neutral. The pinion does not have any play when testing it by hand and also very little slack. It seems like the only thing left not done is the differential. OR, did i miss something that someone out there can tell me that I have not tried? Please let me hear from someone. Thank you. Cliff

couple suggestions. You can narrow it down to rear end/drive train issue by lifting the rear off the ground and running it up to speed. If it vibrates badly like this, you can safely assume it has nothing to do with the front end

You could also pull the axles, the drive line, wheels, etc....to see if it still vibrates... Narrow down where the problem is

If you find an old-timer shop, they may have a on-the-car balancer....our shop does but very few do. This can help correct for badly balanced drums, axles and/or rims/tires.....some of the older cars are very hard to get everything happy, so this method of balancing is very effective if you can find it

Does the vibration change with speed, or does it feel the same regardless? You mention it does it at all speeds, but if it's a driveline issue, I would not expect it to be noticeable below maybe 20 mph, unless something is very warped like a bent wheel or axle.

The idea above of safely supporting the rear of the car on jackstands and chocking the front wheels, then running it up to speed seems like a very practical next step if the vibration is vehicle speed-related.

Do any of the tires show an indication of bouncing such as cupping?

-Rod

I would also check to see that the driveshaft angularity is correct. This means the transmission output shaft and the pinion shaft on the differential must be parallel and have the same angle. They do not have to line up - that's what the u-joints are for - but they must be parallel for the u-joints to work properly or a vibration will result.

HI again. On the 1963 ford fairlane vibration problem, tried not to make my question so I didn't mention how I am testing things. I have another 63 fairlane that is like driving a brand new car as it is so perfect. To test components on the vibrating fairlane, I remove things from the good one to the bad one and drive down the road. Switched the front wheels,drums bearings and all. still the same. Changed all 4 wheels and tires, still the same. Installed new rear wheel bearings. Still the same. Switched the driveshaft. The same. All tires were checked by the best alignment shop in the area and all were perfect but no matter I switched them anyway so it doesn't apply. That shop had a on car balancer but it burnt up in a fire. I have not switched the rear drums so that is next. Also will check driveshaft alignment but car did not start vibrating until last fall and I drove it 2 years without a problem. I did suspect that as the car was modified by putting a 1964 high performance Mustang engine with the same trans. and rear end. That was done 16 years ago and vibration only started last fall so I don't think that had anything to do with it. Will check it anyway. It rains most of the time here in Maine this year so now I will go out in my garage and try some of the great suggestions you guys gave me. Hate to change that differential and find that don't solve it either. Thank you all so much. Cliff.

So it is speed related? At what speed does the vibration set in? If you shift to neutral and speed the engine up does the vibration change?

-Rod

Rod, the vibration is still there when I tried it this way--I got up to about 60MPH just before I got to the top of a big hill. I put it in neutral and shut the engine OFF. Coasted down the hill and it was still vibrating. I hear and feel it the most after about 35MPH and up.At about 48MPH it seems to be very prominent and is still ther at 60 too. Did not try past 60 but I will if it ever stops raining here. Don't take it out in the rain if I can help it. It's too pretty to get dirty and then I will have to wash it. I still wonder if it is in the differential but I hate to go to that expense and work for nothing although the work part of that is easy. The whole carrier comes out the front and no C clips. Just slide the axles out,drop the driveshaft and remove from the front. I am sure you know this but I hate to throw away the money to no avail but I may have to ,or do you not think the trouble is there? Cliff.

HI again. On the 1963 ford fairlane vibration problem, tried not to make my question so I didn't mention how I am testing things. I have another 63 fairlane that is like driving a brand new car as it is so perfect. To test components on the vibrating fairlane, I remove things from the good one to the bad one and drive down the road. Switched the front wheels,drums bearings and all. still the same. Changed all 4 wheels and tires, still the same. Installed new rear wheel bearings. Still the same. Switched the driveshaft. The same. All tires were checked by the best alignment shop in the area and all were perfect but no matter I switched them anyway so it doesn't apply. That shop had a on car balancer but it burnt up in a fire. I have not switched the rear drums so that is next. Also will check driveshaft alignment but car did not start vibrating until last fall and I drove it 2 years without a problem. I did suspect that as the car was modified by putting a 1964 high performance Mustang engine with the same trans. and rear end. That was done 16 years ago and vibration only started last fall so I don't think that had anything to do with it. Will check it anyway. It rains most of the time here in Maine this year so now I will go out in my garage and try some of the great suggestions you guys gave me. Hate to change that differential and find that don't solve it either. Thank you all so much. Cliff.
Given the progressive severity of the problem, check the engine and transmission mounts. One or more may have deteriorated rubber or have broken, causing a progressively more severe driveline angularity problem as the mount deteriorates.
Given the age of the vehicle, if you have not changed the mounts, they are probably pooped.

As a wild idea, look at the rear leaf spring mounts. If you see fresh rust coming out of the spring eye, you may have found it. If the rear is multi-leaf, look for a broken leaf.

Bob