Rotor RUNOUT

WARNING: This page is about a different car, the 2005 Dodge Stratus and 2005 Chrysler Sebring. However, it is still accessible from the selected car via links, so may be relevant.

On-vehicle rotor runout is the combination of the individual runout of the hub face and the runout of the rotor. (The hub and rotor runouts are separable). To measure rotor runout on the vehicle, first remove the tire and wheel assembly. Reinstall the wheel mounting nuts on the studs, tightening the rotor to the hub. Mount the Dial Indicator, Special Tool C-3339, with Mounting Adaptor, Special Tool SP- 1910 on steering arm. The dial indicator plunger should contact braking surface of rotor approximately 25 mm (one inch) from outer edge of rotor. See Fig 1. Check lateral runout on both sides of the rotor, marking the low and high spots on both. Runout limits can be found in the table at the end of this brake rotor information.

Fig 1: Checking Rotor Runout

Courtesy of DAIMLERCHRYSLER CORP.

1 - SPECIAL TOOL SP-1910

2 - 25 mm FROM EDGE

3 - DISC SURFACE

4 - SPECIAL TOOL C-3339

If runout is in excess of the specification, check the lateral runout of the hub face. Before removing the rotor from the hub, place a chalk mark across both the rotor and the one wheel stud closest to where the high runout measurement was taken. This way, the original mounting spot of the rotor on the hub is indexed. See Fig 2.

Fig 2: Marking Rotor and Wheel Stud

Courtesy of DAIMLERCHRYSLER CORP.

1 - CHALK MARK

Remove the rotor from the hub.

NOTE: Clean the hub face surface before checking runout. This provides a clean surface to get an accurate indicator reading.

Mount Dial Indicator, Special Tool C-3339, and Mounting Adaptor, Special Tool SP-1910, to the steering knuckle. Position the indicator stem so it contacts the hub face near the outer diameter. Care must be taken to position stem outside of the stud circle, but inside of the chamfer on the hub rim. See Fig 3.

Fig 3: Checking Hub Runout

Courtesy of DAIMLERCHRYSLER CORP.

1 - HUB SURFACE

2 - SPECIAL TOOL C-3339

3 - SPECIAL TOOL SP-1910

Hub runout should not exceed 0.05 mm (0.0019 inch). If runout exceeds this specification, the hub must be replaced. Refer to SUSPENSION - EXCEPT COUPE .

If the hub runout does not exceed this specification, install the rotor back on the hub, aligning the chalk marks on the rotor with a wheel mounting stud, two studs apart from the original stud. See Fig 4. Tighten nuts in the proper sequence and torque to specifications.

Fig 4: Index Rotor and Wheel Stud

Courtesy of DAIMLERCHRYSLER CORP.

1 - CHALK MARK

Recheck brake rotor runout to see if the runout is now within specifications.

If runout is not within specifications, reface or replace the brake rotor. For information on brake rotor machining, (Refer to BRAKES/HYDRAULIC/MECHANICAL/ROTORS - STANDARD PROCEDURE) .

Brake Rotor Limits

Braking Rotor	Rotor Thickness	Minimum Rotor Thickness	Rotor Thickness Variation	Rotor Runout*	Rotor Micro Finish
Front Rotor	22.87-23.13 mm 0.900-0.911 in.	21.4 mm 0.843 in.	0.013 mm 0.0005 in.	0.10 mm 0.004 in.	15-80 RMS
Rear Rotor	8.87-9.13 mm 0.350-0.360 in.	7.25 mm 0.285 in.	0.013 mm 0.0005 in.	0.10 mm 0.004 in.	15-80 RMS
* TIR-Total Indicator Reading (Measured On Vehicle)