Lateral Runout

1. Measuring requirements: No tilt play of the wheel.





2. Fit adapter plate (Special Tool 9510/1) to wheel hub. Tightening torque of wheel nuts (mounting nuts) is 130 Nm (96 ft. lbs.).
3. Engage dial gauge holder, e.g. Ate Part No. 03.9314-5500.3/01, into the brake caliper, center out and mount by turning the wing screw.

Retract brake pads somewhat if the brake disc cannot be rotated freely.

Do not damage lug for cross spring at the retaining plate of the four-piston fixed calipers when fitting the dial gauge holder.

NOTE: If required, fit dial gauge holder with Ate conversion kit, Part No. 03.9314-5510.3/01 (longer wing screw and bracket for dial gauge if necessary).





4. Fit dial gauge with a slight preload. Place measuring pointer on largest diameter of brake surface outside of perforation.
5. Rotate brake disc and read off runout on dial gauge.

Max. permissible lateral runout of fitted brake disc: 0.09 mm.
Lateral runout of removed brake disc: max. 0.05 mm
Lateral runout of wheel hub: max. 0.04 mm.

6. If the lateral-runout of the brake disc exceeds 0.09 mm, remove the brake disc and check lateral runout of wheel hub. Before dismantling, mark position of disc on wheel hub.








7. Check runout of wheel hub as follows:

Measure once outside (arrow) and once inside wheel stud area of hub face.

To fit the dial gauge, use either a universal dial gauge holder, e.g. by SNAP-ON (Part No. PMF 137), or a modified (extended) dial gauge holder VW 387.

NOTE: Make sure the brake hoses and brake pipes are not damaged when the brake caliper is removed and installed.

8. Excessive lateral runout of wheel hub:
^ Replace wheel hub.

Lateral runout of wheel hub o.k.:
^ Clean leveling and centering surfaces of brake disc and wheel hub. Then apply a thin coat of Optimoly TA to centering surface of wheel hub.

^ Fit brake disc to wheel hub in a different position offset radially with regard to wheel hub.

^ Repeat measurement with adapter plate fitted (Special Tool 9510/1).

^ If the lateral runout is still in excess of 0.09 mm, the brake disc must be replaced.

NOTE: If the brake disc runout has been reduced by offsetting the brake disc radially with regard to the wheel hub, one 6 mm countersunk head screw may be omitted if two 6 mm screws had been fitted.