Primary cause for Front end shimmy

MR.GADGET

MEMBER
1986 CHEVROLET CELEBRITY
14,800 MILES

Primary cause for Front end shimmy.
I own an '86 Celebrity Eurosport that has been the best car that I've ever had. Now age has caused the typical front end shaking at road speeds. (Above 45 MPH). What is the most common worn parts that cause this? I'm thinking ball joints, would that be right?
No local shops are willing to look at it due to it's age, but to me it's almost a classic.
HINTS; Steering is still tight and smooth.
Putting a tire that is one size larger on the drivers side calms the problem down and you can drive at 65MPH. (Due to shifting vehicle weight?)
Sometimes you can hear a distinct rattle sound from the center under the floor boards at the same time.

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

A vibration in the steering wheel is usually not the direct result of worn parts. The easiest place to start is by measuring the ride height. Sagged coil springs will change the geometry of the suspension system and half shaft angles. That can set up a vibration at certain speeds.

A tire out-of-balance is a common problem. I find it hard to believe no shops will check that. The age of the car has nothing to do with the services they offer. This isn't obamacare where we don't work on older models. If any wheels were recently removed there can be rust and debris that fell in or got stuck between the wheel and brake rotor or the rotor and hub. Anyone at a tire and alignment shop can inspect the steering and suspension components and they will be able to identify the cause of the vibration.