Brake Drum and Hub Radial Runout Check - On-Vehicle

1. Remove wheel.

IMPORTANT: Be sure drum and hub surfaces are free of debris and corrosion

2. Remove brake drum and install on hub backwards; secure drum with two wheel bolts.
3. Fasten a dial indicator to the knuckle or strut-to-knuckle fastener.
4. Position dial indicator tip against brake drum shoe surface.
5. Rotate drum to lowest reading.
6. Zero the dial indicator.
7. Rotate drum one complete revolution and observe Total Indicated Runout (TIR).
^ If combined brake drum and hub radial runout does not exceed 0.10 mm (0.004 inch), proceed to step 8.
^ If combined drum and hub radial runout exceeds 0.10 mm (0.004 inch), proceed to step 14.
Maximum TIR (combined brake drum and hub): 0.10 mm (0.004 inch)
8. Move dial indicator neck to allow removal of drum. It is not necessary to remove dial indicator from knuckle or strut-to-knuckle fastener.
9. Remove drum from hub and turn 180 degrees and again, install on hub backward. Secure brake drum with two wheel bolts.
10. Position dial indicator tip against brake drum shoe surface.
11. Rotate drum to lowest reading.
12. Zero the dial indicator.
13. Rotate drum one complete revolution and observe Total Indicated Runout (TIR).
Maximum TIR (combined brake drum and hub): 0.10 mm (0.004 inch)
^ If combined brake drum and hub radial runout does not exceed 0.28 mm (0.011 inch), brake drum and hub are within specification and no repair is required.
^ If combined brake drum and hub radial runout exceeds 0.10 mm (0.004 inch), proceed to step 14.
14. Remove drum and install on a brake lathe.
15. Fasten a dial indicator to brake lathe.
16. Position dial indicator tip against brake drum shoe surface.
17. Rotate drum to lowest reading.
18. Zero the dial indicator.
19. Rotate drum one complete revolution and observe total indicated runout.
Maximum TIR (brake drum): 0.15 mm (0.006 inch)
^ If brake drum radial runout exceeds 0.05 mm (0.002 inch), refinish brake drum as long as refinishing does not exceed brake drum maximum diameter of 230.65 mm (9.08 inch) after turning.
^ If brake drum exceeds maximum diameter, replace brake drum.
20. Subtract Total Indicated Runout (TIR) measurement obtained in step 19 (brake drum runout) from TIR measurement obtained in step 7 (combined brake drum and hub runout). The difference between these two readings represents hub runout.
Combined Drum and Hub Runout - Drum Runout = Total Hub Runout
Maximum TIR (combined brake drum and hub): 0.10 mm (0.004 inch)
If hub runout exceeds 0.05 mm (0.002 inch), replace hub and bearing assembly.