Strange wheel "Hopping" on full steering lock

Strange wheel "Hopping" on full steering lock

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Tempest_5

Original Poster:

603 posts

198 months

Monday 29th October 2012
quotequote all
I'm experiencing a strange effect on the front wheels of my Westfield when I move it with the steering on full lock. I get a sort of hopping/wobbling sensation from the wheels. This follows getting it back on the road after having it laid up for 8 years. During this time I refurbished a fair bit of it including replacing all suspension bushes, ball joints & tyres. I have checked all the ball joints for play with the front end on stands & on the ground but all was correct. I checked the bearings for play but they seem alright. I mentioned this to the garage when it had it's MOT but they could find nothing amiss either.

Nothing feels out of balance or loose when driving.

Any ideas anyone ? Strange load angle on the bearings at full lock causing it ? the rubber on the new tyres bunching up then releasing ?

martycossie

90 posts

175 months

Tuesday 30th October 2012
quotequote all
flat spoted tyers ? when been stud?

Tempest_5

Original Poster:

603 posts

198 months

Tuesday 30th October 2012
quotequote all
We thought about that but I've got new tyres on it. Shame as that would have been a simple one to fix.

The Wookie

13,979 posts

229 months

Wednesday 31st October 2012
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When you say 'hopping' do you mean it's stick-slipping a bit from the front when you're manoeuvring? Like the front is repetitively jumping a fraction towards the outside of where you're turning?

Were the old bushes soft or did you replace them with stiffer (e.g. polybush) items?

It could be that the car has a low ackermann setup and in replacing the bushes with stiffer items you've reduced the compliance in the front end that's stopped it from happening before. You get this effect on quite a few performance cars.

ETA - Could also be that the alignment isn't quite right where you've replaced things, but it's essentially the same issue. I'd check the alignment but failing that it's probably just normal behaviour. In fact wouldn't be surprised if it's just because the tyres are brand new and it goes away after a few hundred miles!

Edited by The Wookie on Wednesday 31st October 12:01

Tempest_5

Original Poster:

603 posts

198 months

Wednesday 31st October 2012
quotequote all
It feels like the wheel is loose or has a flat spot like Martycossie suggested, however it only occurs on full lock. The bushes are the same rubber ones as original fitted. I have spoken to some of the other petrol heads at work and one with a Stag reports a similar experience.

I see what you mean about the geometry, the two front wheels might not have the same turning centre and are fighting each other. I think it will have to be a conference in the car park at work one Friday lunchtime with some of the lads. I'll let you know what we come up with.

Adam205

814 posts

183 months

Monday 5th November 2012
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Do you have an LSD fitted?

Evoluzione

10,345 posts

244 months

Monday 5th November 2012
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Check the tracking.

You don't have wheel spacers fitted do you?

matjk

1,102 posts

141 months

Wednesday 7th November 2012
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Could be the ackermann effect,

Have this on my porsche, only happens if the tyres are really cold (from now till Feb)on my car!
On full lock it feels like the wheels are getting stuck every so often, thought it might be brakes or suspension at first.

http://en.wikipedia.org/wiki/Ackermann_steering_ge...

matjk

1,102 posts

141 months

Wednesday 7th November 2012
quotequote all
Could be the ackermann effect,

Have this on my porsche, only happens if the tyres are really cold (from now till Feb)on my car!
On full lock it feels like the wheels are getting stuck every so often, thought it might be brakes or suspension at first.

http://en.wikipedia.org/wiki/Ackermann_steering_ge...

Skyedriver

17,975 posts

283 months

Tuesday 20th November 2012
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Lotus Excel does this as it has no Akerman angle