Imperial Home Page -> Repair -> Wheels & Tires -> Vibrations
Tip from Kerry:
My 'new' 64 had very good tires on it when I found it, probably 90% wear remaining. However, when I got it running and up to about 50, there was a terrible vibration. I pulled the tires and took them to Goodyear (brother-in-law works there). We put them on the balance machine and you could see that every tire was out of round at least 1/2 inch. This car had sat in one place for at LEAST 3 years and the tires had taken a permanent set.
With 4 new 235-75/15s the car rides great but I noticed the old tires still have the radial 'pooch' shape even though they are not even mounted. All they are good for is putting on a project to push around the shop.
The moral of this story is this, if you are going to store your car, put it on jack stands to take the weight off your tires.
Question from Tony (1961):
Many thanks to all who sent me advice on my noisy rear axle. Here's the latest. 1. I do not have sure-grip. 2. The shocks and shock bushes seem fine. 3. I have drained the oil and to my surprise it was clear and fresh looking. Certainly no metal chips or sludge. 4. The noise and shuddering seem to be coming from the driver's side wheel. That's as much as I had time for today but maybe it narrows down the possible causes. Strangely, although the oil looked clean, the drain and filler plugs look like they have not been disturbed for years.
Reply from Joe:
Don't overlook the possibility of a tire which has tread separating as it is driven. Once years ago, I had a tire do this and it almost drove me and a tire dealer nuts until it got far enough advanced to show up when sitting still. It would probably show up on a spin-balance though. At first when the car was at rest, there was no indication of any problem, but, on the road it would vibrate like mad.
Question from Chuck (1981-1983):
I purchased "Beauty", an '81 Light Auburn Metallic Imperial a month ago and >during the drive home of almost a 1000 miles, the car had a strong vibration throughout the speed range and was very noticeable at speeds of 65-75 MPH. The day after arriving home I took it to our local tire store and had all four wheels balanced. This was a definite help to my problem and around town and at speeds of 35-55 is fairly smooth. I do notice vibration, however, at speeds above 65....its noticeable in the seats and steering wheel. Could it be the drive shaft? What are the symptoms of drive shaft unbalance? What else could be affecting the ride? The tires are Goodyear Double Eagles.
Reply from Paul:
I recently bought my '75 Newport (Feb 2001) and it had a strong pull to the right as well as a knock from the left front. I figured the knock was bearings so I bought new ones but they didn't fit and I also discovered a loose race (bad rotor). An easy fix for my rotor was to take one from my '78 Newport (derelict) which produced a HEAVY vibration above 45MPH (enough to keep me under 45). I've kept driving it this way (slowly) while making preparations to fix it (taking the spindle from the '78 and buying new ball joints) and also needing front tires. The day I decided to look at tires I got them, then discovering that I had different width rims (5 1/2 on the left, 7 on the right) which I was told could cause a pull so ........ I told them to hold off on the alignment (I decided that was part of the problem) until I could return with another 7" rim I knew I had ..................... WHAT A DIFFERENCE!!!!! Just the tires eliminated the vibration and the pull (though it still had a very slight pull) --- I got my rim, had them swap the tires (the 7" had an old one that is now on the 5 1/2 for a spare), and only needed a slight toe adjustment. Though my Newport is RWD (aren't the 80's Imps FWD?) definitely check your tires first.
Follow-up from Dick:
Of course, the wheels should be the proper ones for the car. The wheels on the 81'- 83's are 7 inch rims. If you have steel wheels on the car, this is worth checking to track down a pull to one side or the other. Actually, even mismatched tire treads will cause a car to pull to one side.
Question from Pete:
Well, I must have the slowest Imperial of the group. I can't go above 85 before I get a severe driveline vibration. I've replaces engine/tranny mounts and all 4 u-joints. No difference. Tried putting the driveshaft 180 degrees out-of-phase. Nadda. I think its the rear end. Its getting kinda noisy (I notice it at low speeds). I have to find a local vendor that works on sure-grip units, but no luck so far.
I don't think that the rear end could make such vibration at 85 mph, did you try to have the wheels balanced ?
You can also have the driveshaft checked to make sure it's not bent. Other possibilities, bent rim, tire bubble (where the tread starts to separate from the carcass), and front end alignment. The rear end noise could be the outer axle bearings. Locking differentials tend to act up more when cornering than in a straight line. (In my experience, I could be wrong) There's an additive you can get for posi type rear ends. It's about a pint, I don't remember the name, but it eliminate the squawking, squealing, and horrible shrill noises that my 1976 Dodge Power Wagon was making. Your local autoparts store will have it. Just tell them you want some posi lube.
I second the above advice regarding tire balancing. I had terrible vibration problems with my '66 LeBaron. I swapped the tires off my convertible and the problems disappeared. It was smooth as glass. Of course, this was after I had the entire front end totally rebuilt and the driveline rebuilt and balanced. When none of those fixes had any effect whatsoever on the vibrations, I zero'ed in on the tires. Despite having had the tires balanced, trued and shaved for roundness, they were still the sole source of my vibration problems. A new set of Firestone 770's cured all ills. Also, if you have a '61='66 Imperial, remember their "swiss cheese" wheels bend easily. Check to see if the wheels are still true, and not wobbling as you go down the road! Both the convertible and LeBaron had one bent rim when I bought the cars - discovered when I took the cars in to have wheels balanced. Like a retired airline mechanic once told me: ALWAYS CHECK THE EASY STUFF FIRST! I wish I had done that before I spent all that money on front end and driveline work!
This page last updated October 8, 2003. Send us your feedback, and come join the Imperial Mailing List - Online Car Club