Vibration at 60 MPH

[Dennis Nelson]

I have two friends who are having ongoing troubles with their TR4As. Both suffer from a vibration at about 60 MPH. One has replaced tires, and the other has changed wheels, with neither seeing any relief. The vibration seems to come up the steering column. Are they just unlucky, or is there a known bug or series of problems that might explain this?

 

thanks .... djn

Edited September 24, 2007 by Dennis Nelson

[BrianC]

Assuming that the wheels are true (and no loose spokes if wires) and tyres are balanced, and the wheel bearings are correctly adjusted, I would suspect loose or soft steering rack mounts.

I had this problem on my previous TR4A and careful adjusting of the mounts fixed it for me (solid mounts were not an option back then).

Edited September 24, 2007 by BrianC

[RogerH]

Hi Dennis,

if everything else appears ok check out your front dampers. They may be soft or simply resonate at this speed.

 

Roger

[ianc]

It is not unknown to find

(a) the tread wanders from left to right as the wheel is rotated - easily spotted with the wheel elevated and spun

( there is a bump in the tread where the overlap occurs in the carcase - once again, easily spotted with the wheel elevated.

Either of these defects can upset the steering, especially if some of the components (see above) are not in top nick.

On a solid axle car, put such tyres onto the rear axle, where you won't feel a thing!

Ian Cornish

[Horse]

One other thing you may want to get checked is the play in the trunnion bearings at the bottom of the upright. I have jst had these replaced (very worn - found on MOT) on my 4A and although my steering shake has not been eliminated, it is greatly reduced.