Whole lot of shakin' goin' on

[Dan George]

My '59 Cab has a noticeable shaking problem. On a scale of 1 to 10, it's a 3 or 4. It's not so bad that I'm concerned about losing control of the car but it's annoying. It begins at 63 mph and becomes more obvious as the speed increases until about 75 mph where it goes away. It's most noticeable through the steering wheel but can be felt to a lesser degree throughout the car. While it doesn't always do it, it does it more often than not. The car underwent a rotisserie restoration and the front suspension was entirely rebuilt. A check of the suspension and steering parts showed no looseness or wear. All the wheel and axle bearings feel and sound good when I turn them. The tires are new and balanced on 5 1/2 wide rims and I have checked out all for wooble and roundness and all are within tolerances. I switched wheels and tires with a friend's '58 which I know to be a smooth driving car, and my car still shook at the speeds noted above. Anyone have any thoughts as to the cause?

[Dan Epperly]

My '59 Cab has a noticeable shaking problem. On a scale of 1 to 10, it's a 3 or 4. It's not so bad that I'm concerned about losing control of the car but it's annoying. It begins at 63 mph and becomes more obvious as the speed increases until about 75 mph where it goes away. It's most noticeable through the steering wheel but can be felt to a lesser degree throughout the car. While it doesn't always do it, it does it more often than not. The car underwent a rotisserie restoration and the front suspension was entirely rebuilt. A check of the suspension and steering parts showed no looseness or wear. All the wheel and axle bearings feel and sound good when I turn them. The tires are new and balanced on 5 1/2 wide rims and I have checked out all for wooble and roundness and all are within tolerances. I switched wheels and tires with a friend's '58 which I know to be a smooth driving car, and my car still shook at the speeds noted above. Anyone have any thoughts as to the cause?

Have you adjusted your link pins lately?

[David Jones]

Dan, I feel for you. My 59 cab does the same thing though I have ameliorated the situation somewhat recently. I bought the car back in 99 with a salvage title and after rebuilding it I was very happy with the handling and stability but as time went buy it started to develop what as a Brit I called "scuttle shake". I did all the things you have done including a very careful check of the alignment. I also switched drums and wheels from my 59 coupe and all to no avail. Recently I completely tore the whole front end apart and checked all the bearings and bushings in the beam and actually flipped the trailing arms side to side. When I put it back together it was with no play anywhere but although I reduced the shake it is still there. It comes in now at about 57 mph and stays until about 63 mph then smooths out again. I just replaced the Koni shocks with some Cofap shocks I had on the shelf to see if that makes any difference. It has been raining since I changed them so I have yet to see if that makes any difference. One other thing I have to do is take it to a tire shop that can balance wheels on the car. If they can spin up the wheels to the critical point and they shake I may be able to pinpoint the problem.
I will let you know.
Oh and I also replaced the steering box and steering damper and double checked the tie rod ends.

[Mike Wilson]

Everything in the front end to the steering wheel has to be methodically checked from the tires, rims, bearings to suspension, tie rods and ends to steering damper and box. It could be as simple as a loose clamp on the steering box yoke ( an issue I had).

Keep us posted.

Mike

[Martin Benade]

Generally that 57-63 is shake is tire balance, it is typical that higher speeds make it get less or gone. I am surprised that Dan's car is unchanged with the other tires on it. Even with loose or bent parts it takes an uneven force such as a bent rim, out of round tire, or out of balance tire to make the loose stuff start shaking. The one other thing you should try is loosening the brake adjustments to where there is zero drag. I often see disk brake cars with one dragging caliper that will shake when the rotor gets hot and wavy. It can come and go as it pleases.

[Sebastian Gaeta]

Anyone have any thoughts as to the cause?

Front brake drums not perfectly round, check them on a lathe. A drums are especially susceptible.

[Martin Benade]

My suggestion to loosen the brake adjustment is for testing only, unless they were excessively tight to start with. I would check all four wheels.

[Alan Winer]

I agree with Sebastian. A major cause of front end shake on early British cars, like my Healey's, are the front brake drums or the wheels/tires out of balance. Typically at the 57-60 mph range. It just seems to set up a resonance at that speed.
Alan

[Al Zim]

You should check the date on your tires. If they are over 10 years old replace them even though they look new. I would use Michelin or Bridgestone tires they are better built and round. You get no value when you use Pacific rim tires. Your tire shop should have a balancer with the adapters for the large bolt diameter of early VW and Porsche. If they do not have this try another place. Over the last year we have managed to end up with a large batch of chrome 356A/B wheels. Most of them are bent from poor construction in Pacific rim countries. These need to be checked before the tire is installed. While the car is in the air, grab the wheel top and bottom to check the link pin wear or the spindle wear. If the spindle wiggles on the king pin, this is easily visible, probably due to enlargement of the king pin hole in the spindle. This can be repaired. Wheel bearings should be tight, pulling the wheel in and out will provide a clunking noise of the gearing is not adjusted properly. Also check your tie rod ends. If they wiggle as you are moving the wheel from side to side that will also enhance a vibration.
The brake drum will turn with the wheel. The construction of the brake drum is such that there should be no imbalance or flexing of the brake similar to what would happen with a rubber tire that breaks a cord or gets flat spotted. al zim If you put the brake drum in a lathe and shave inner material then the lining will crack, if it is not cracked you will need oversize brake shoes for the brakes to function properly. Removing metal from the outside of the drum will probably have the same result as removing the lining. DO NOT DO THIS. al

[Alan Winer]

The brake drum is spinning just like the wheel and tire.

[Sebastian Gaeta]

The brake drum will have no bearing on vibration because the brakes are not applied at 60+ MPH.

They most certainly will if they are not concentric. If you put the drums on a lathe and you are shaving off material, then there is the source of your whole lot of shakin' goin' on.

[Jim Liberty]

Alan, if ever there was an AH that said it all, it is yours. Everything after 1955/56 was just a lot of chrome screwed on. Less is always more. .....................Jim.

[Alan Winer]

Thanks Jim,
I must confess, I added Lucas Flame Throwers to the front apron, no bar. The early Healey's have great lines and are a great ride, but mechanically they're kinda inferior to the 356's.
I had heard that you built a mega Bug-Eye.
Alan

[Jim Liberty]

Well, it is just another of my over doing stuff. It has a Judson blower, front disks, Abarth, Lucas Flame Throwers,

etc. More fun than a 356 from 30 to 50. When they are not leaking, you know you are out of fluids. .............Jim.

PS. I just finished a Fiat Abarth 500 (695). All NOS mechanicals, and interior.

[David Jones]

I rallied a bugeye a few times in about 1970 with a mate in the RAF just before I bought my first 356. We broke the chassis of the bugeye in half with a heavy landing over a humpback bridge over a canal in England. We repaired the floor with many rivets and duralumin sheet courtesy of the RAF and sold it real quick and switched to a mini. Needless to say the mini was way more competitive while my 356 being a normal and with 6 volt lighting was just not up to the task.
Just another tale of not knowing we could not do what we ended up doing anyway.