VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Bad vehicle vibration on freeway - 1953 Chevy

Hello fellow chevy enthusiasts,
I was driving on the freeway from a car show in my 53 (original 235 engine)last week & at 60-65 mph the entire car was shaking. It doesn't seem to do this at around 50 mph. It's done this before but I have not addressed it. Also the speedo needle sways back & forth at 65mph but not at a slower speed. The windows were vibrating as well as the aerial. I have firestone 670 X15 bias ply tyres on it and wondering if this is the reason ? I have never had a front wheel alignment done on the car, although the 4 wheels were balanced with weights at a shop about 5-6 years ago (separately off the car), nothing done since. I don't want to throw the tyres away and put radials on. The Firestones are about 10 years old but in good shape with very little wear, can't see any cracks on the tyres. Someone told me it is either a wheel balance problem or possibly a problem with the tail shaft ? I don't want to push this car anymore than 60mph on the freeway as I'm concerned something will give as well as the safety factor. I don't know if shaking at this speed is normal for a car of this age. Anyone else experience this problem or have any ideas ? Many Thanks Tony

I'd say if the shaking is really agressive then i'd have to agree that the tail shaft may not be aligned proper. Some describe this shaking very violent. It COULD also be tires. A busted belt or out of balance. Usually that wont be as violent as a mis-aligned tail shaft though.


Im not sure but it's something to keep in mind on firestone. Im not 100% sure on tires made for the OLDER vehicles but i know todays modern firestones for modern vehicles are made in japan and are pretty reputable about busting belts and litteraly falling apart under speed.

Tony,

It may be possible a wheel has shed the wheel balancing weight(s).

I would rotate the tires, front to rear, then road test it again, same speed, same road. If the vibrations seems somewhat different, I would lokk at the tires and or wheel weights ( rebalance).

If the vibration appears identical after the rotation, it may be in the driveline itself.

Bob

Thanks Oilspot & Bob. The tyres I have are made in USA Firestone, but I will get the wheels re-balanced /rotated then check it again on the same freeway stretch at 65mph. Hopefully then we'll know if it's a balance or tailshaft problem

Guys,
Following up from this I took the car to a tyre place where they removed all 4 tyres and checked the balance, it was negligible maybe 10-15g out, so balance was basically ok.
The problem is although the tyres have no visible cracks they are all out of round. They are Firestone (670 X 15) Made in USA (3 1/4 inch white wall) and they've been on the car 10 years. The guy said the problem is if a car sits too long in one spot these type of tyres will go out of shape, causing vibration at a particular speed. When they were spun on the balance machine the out of round was pretty obvious. He told me that radials won't have that problem as they have a steel belt, so am thinking of going the BF Goodrich white wall radial equivalent next year. I know they are not correct but I'm hoping that even if the car sits (1-2 months at a time) they won't go out of round like the bias ply tyres

Through the years my cars have sat many months without the tires rotating and I have never had a problem. If the car was last parked when the tires were hot sometimes they would have slight "flat spots" when I drove it again but would go away as the tires warmed up during driving.
Last year I took the 25 year old Firestones off my 1950 and they were still fine, had almost 30,000 miles on them including a 3000 trip to Colorado in 2006.
In my experiance I have found both the Firestone and Goodrich tires I have on my cars to be slightly out of round and have some )side) runout but were always satisfactory for 65 MPH driving.
The new tires came with a sticker with a warning that the tires should not be computer spin balanced due to the fact that the white side weighs more than the black side. I have balanced mine with my bubble balancer with good results.