steering madness

[orangecurry]

I have 15" BBS which I use in summer (low mileage wheels with quality tyres) and 16" Hartge which need a refurb in an ideal world, so I use them as winter wheels (easier to clean as well)

When I swop from 1 set to the other, I have to move the steering wheel 1 or 2 splines over.......

anyone care to explain that one please?

I noticed this last year as well (with a different 'pairing' of the Hartges on the front last time)

Rolling diameters are the same, 205/55/15 vs 205/50/16, though I suppose as the Hartges are 7.5 J the footprint will be slightly wider.

Hey I know some of you have REAL problems, but I just want to KNOW!!!

[Martinaston]

Sounds like worn out ball joints or wheel bearings

[astondg]

You didn't say if the wheels have been balanced? I know you said you tried a different pairing but if you could get them balanced just to be sure it could rule that out.

Otherwise I have no idea, it must be something in the steering/ suspension/ bearings/ etc. but I don't know why it would only happen with one set of wheels and tyres. Wider and lower profile tyres will tramline more somtimes I think my steering is out because I have to hold the wheel slightly to the right to go straight but then I get on another road later and I have to hold it to the left and sometimes it will be straight like it should and that is with 205/50/16s.

Aston

[orangecurry]

thanks for your thoughts chaps - as I said it's a puzzler.

No wear in the steering anywhere - corners like it's on rails (for a 1980's design!). The Tyres on the 15's have more tread depth, but the 16s that were on the front last year have as much depth, and the 16s on the front now have a lot less depth.... but the effect on the steering wheel is EXACTLY the same.

The car doesn't pull in either direction with either set - can't see how it is balancing; that shouldn't effect the steering rack position.......

all I can think of is that the 15s are 7J, and the 16s 7.5J, but why would that rotate the steering wheel?

[johnna]

What about the tyres? Are they uniform throughout? I mean the same brand, same tread pattern? A different tread from on front wheel to the other could cause some 'drag'.

[orangecurry]

edit to answer you Q directly, the tyres are matched make/size/depth/(wear even ) on the axle!

no I'm sorry I'm not being clear.....

it's out even when stationary...

if I simply swop over the wheels, to get the car to roll in a straight line, the steering wheel is 1 spline to the left (i.e. turned anticlockwise) with the 7.5J Hartges.

Then driving down the road it's the same.

Then if I swop back to the 15" 7Js, the steering wheel is back dead-centre.

So I can't see how the quality of the tyres or the balance of the wheels or anything similar could be the cause...

just leaves the width of the wheel and the offset difference (24 instead of 25 from memory)

is the steering rack somehow 'moved over' by this tiny change?

[dazleeds]

have you checked the splines in the steering wheel boss???

this happend to me recently similar confuzzled me for
hours till i notice splines were worn and steering wheel wasnt locking to column shaft and would turn slightl and go off line

worth a look mate

[orangecurry]

I like that - lateral thinking!

good one but no - why would it always go back to 'how it was' for each set, and ONLY moves on the day I swop the wheels?