991 GT3 Wheel Alignment - Play in Rear Wheel Steer

[blueSL]

Took my GT3 to Centre Gravity today to set it up and everything ground to a halt when we found play in the rear-wheel steering. Lift the car off the deck, grab a rear wheel at Quarter to Three and you can rock the wheel, we measured it as 0.1 to 0.2mm at the rim. Seems to trace back to the rear wheel steering actuator and they told me the play was enough for the car to fail the MOT. Since this movement is greater than the setting tolerance, there was no point in continuing. The car pulls to the right, especially under heavy acceleration.

So now the long slog to get the OPC to replicate the problem (assuming it is such) and fix it. The OPC said the key has to be out of the ignition for the test to be valid, CG says the ignition has to be on. Who is right?

Anyone else seen this problem?

[blueSL]

Thanks, so the OPC were talking nonsense. i expect there is some sort of reset of the RWS when you switch the ignition on. Thanks for the tip about the steering sensor.

[blueSL]

With the wheels off the deck, you can grab them at quarter to three and push and pull in the direction the RWS operates, clonk, clonk.

It was only 0.1mm, 0.2 on the other side, but I'm hardly exerting the same forces as it would see on the road. Car has done 3500 miles.

The geometry is out, CGs view was that there was no point doing it because they do the back first, then the front and this play would create a dead zone around the centre.

Thanks for the info on the replacement, I'll get in touch with my usual dealer and see what they say.

[blueSL]

Same as Taffy59, you can feel the rim moving, not just the tyre. We measured it using a dial gauge and also reproduced it exactly with the Hawkeye attached and running. Grasp the rim and the figures change.