Whilst fitting some wheel spacers to my Gransport it has become apparent that the left hand rear wheel is closer to the wheel arch (widthways) than the right hand side. Is it possible that the rear subframe has been refitted slightly off centre following a clutch change? I had a 4200 a few years ago, and this was exactly the same - I can’t believe this is how they are supposed to be? Can this be adjusted?
How are you measuring the gap between the wheel and the arch on each side ?
In order to get a true measure of how far it is out and possible causes then you need to measure the gap both sides from at least 2 different points of the 360 degrees of the tyre / wheel. 3 points would be better at 90/180/270 degrees.
Use a spirit level to find absolute level across the center cap and use some low tack tape on the body panels both sides of the wheel so that you have a level static measure point that can not move in between measuring.
Assuming you have matching tyres pick a point on the side wall to measure from each side of the arch to the tyre. Ideally you want to use either the rim protection bead on the tyre or if it has a line all the way round the tyre where the logo is then one of those will do.
Once you have the measure points on each side put 2 / 3 bits of tape on the rims at 9/12/3 o'clock positions.
Measure the gaps between arches and wheel/tyre measure point at the 9pm position and note them down for both sides. Roll the car forward so the 12 o'clock marker is now at the 9 o'clock position and measure again. Taking note again. Move the car forward again until the 3 marker is where the 9 o'clock marked was and note the measurments.
Are the measurements different on each side of the car ?
Do all 3 measurement stay the same on both sides of the car ? If they change on one side only then i would suggest that either your tyres are out of round or you have a buckle in the wheel. You could take the 3 measures again to the rim of the wheel and see if they still change. if thats the case the result would show the wheel itself is out and has a buckle. If it doesnt change its your tyre that is out of round or not seated on the rim correctly all the way round.
To get the most accurate measue i would also check and set your tyre pressures before you start the process.
Ive seen pirelli p zeros tyres that have gone egg shaped on a car which was in daily use. Not flat spotted but actually egg shaped when rolled across a floor.
If you can eliminate the wheels and tyres then you know your looking at either its the set up of the car from factory, camber set up or rose joint issue.