They can be measuered from top most rim to structural member above. 17mm new, 13mm collasped. Use a scoket with correct OD as a feeler gauge.

Usually felt in seat of pants and steering wheel in gear while stopped.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)