Full lock judder

[lazyitus]

When going slowly on full lock, there is a judder from the front end. It feels as though it has a flat tyre (but hasn't.)

Could this be something to do with the steering rack?

Or what?

[shpub]

More to do with steering geometry. Fairly common characteristic and nothing to be too concerned about.

[lazyitus]

Good! Thanks Steve.

[Painey]

I've got a similar problem on my griff but it's only appeared since having a new set of Toyo's fitted. It doesn't bother me that much and I haven't been back to the garage that fitted them, was just wondering if anyone else has ever heard of this problem??

[GreenV8S]

You sure they aren't catching on anything? Sticking diff is another possible cause. Haven't come across tyres doing this on their own, but that doesn't mean it can't happen.

[lazyitus]

Hi Peter,

Pretty sure its not catching anywhere but I'm going to check tonight. Feels like a front end thing so I think the diff's out of the equation.

Thanks

[Ballistic Banana]

If the steering UJ's have the intermediatte rod pushed throught to fare they can catch the UJ on full lock making it Judder/knock.
BUTcant see that happeneing unless someone has dont some work recently on it or the uj bolt has come loose.
Hope that doesnt worry you unneccesarily

BB

[lazyitus]

Ballistic Banana said:

If the steering UJ's have the intermediatte rod pushed throught to fare they can catch the UJ on full lock making it Judder/knock. BUTcant see that happeneing unless someone has dont some work recently on it or the uj bolt has come loose. Hope that doesnt worry you unneccesarily BB

Dont think its that. I'm inclined to go with Steves offering on this one. (Not just 'cos its worry free!)

Its going for a 12K next month anyway, so I'll get it properly checked out then.

Cheers
Lazy

[pete]

It could be due to the Griff's "low Ackerman" steering geometry. The Ackerman angle is the amount by which the angle of the outside and inside wheels' steering angles differ, to take account of the different radii they describe when turning.

If you make the wheels turn in parallel (no Ackerman), steering response is stable at high speeds/low steering inputs, but the inside wheel gets dragged around a tighter radius than it's turned for at full lock, hence the juddering. Steering with a fully corrected Ackerman angle can lead to high speed instability, not to mention being a shed-load harder to design

Pete

[beano500]

"They all do that, Sir"

Phew! Haven't got one of those out for a while

I think you'll find that it is, as per everyone's suggestions a combination of steering geometry and tyres. I've noticed the same on my car - usually accompanied by the wheezing of the PAS, when this was weeping - ever since I had it, and was told that nothing was wrong. If anything it has been more noticeable since I had my wheels aligned a few ks back.