Steering racks and wheel wobble

[david.g.chapman]

I've just have new tyres fitted to my +2, and I still have a bit of wheel shimmy at around 70 mph. I was just wondering what effect any play in the steering rack would have, so I've jacked up the front and examined the rack....

1. No play in the track rods (inner ball joints and outer steering joints.
2. Wheel bearings correctly adjusted.
3. No side to side play in my solid steering column.
4. Rack mounts seem to be firm (OE rubber).
5. No play between turning the steering wheel and movement of the front wheels, although I can hear a single soft clunk after 5mm of steering wheel movement, coming from the pinion area?
6. New trunnions and uprights fitted recently.

Is it worth pulling the rack and looking deeper or could it be anything else?

Dave Chapman.

[ericbushby]

Hi Dave,
Before looking for trouble have you tried swopping the wheels front to back to see if it is still a wheel balance problem or a wheel out of true.
Even within the specification of 50 thou` axial runout I still had some wobble if it was on the front of the car. The rogue wheel was OK when fitted on the back.
best of luck
Eric in Burnley
1967 S3SE DHC

[h20hamelan]

No play in the bearing?
Agreed on wheel out of balance as it starts @ 70

[elans3]

Agree as above, balance first, if still there, investigate further. More likely balance than anything else. Some places find it hard to balance these old wheels..

[alan.barker]

Hi Dave,
Have the rear wheels been balanced also.
Alan

[shynsy]

Had recurring issues with vibration at 70 with my first +2. Only solution I found was getting all 4 wheels dynamically balanced on the car. There was a place near silverstone which did it. Slightly frightening seeing the guy spin the wheel up to 80 mph without the car moving.
Tim

[david.g.chapman]

Thanks for your replies.

That's my feeling about it, despite the wheels being balanced at the tyre shop. I will resist looking at the rack for now, and start my on road balance technique....

1. Fit a 10 gram stick on weight somewhere on the first front wheel (I have Lotus alloys).
2. Road test.
3. If wobble is worse move weight through 120 degrees and road test.
4. Keep going until it gets better. It usually does!
5. Repeat for the other wheel.

Update: All of the wheels have been balanced. I once had my wheels balanced on the car at a place in Ilford. They had an ancient balancer and the result was disappointing. The Silverstone venue has gone into my memory banks!

Cheers,

Dave Chapman.

[h20hamelan]

not all tyre shops are equal.
do they offer match balancing around, or a trusted race shop that will spend the time and make sure its correct