Tips for measuring rotor run out?

[The73vetteman]

OK, so now I have the front hubs fitted out with new bearings, mounted on the spindles, and I want to check for rotor runout. I borrow a dial gauge and a couple of rods but I can't figure out how to mount it off the spindle nut.

How do you experienced guys do this?

'73

 

[Jack]

If the dial indicator mount has a magnetic base ... slide a ramp under there and stick the base to the ramp ... or stick it to an unloaded caliper.
JACK:gap

 

[GTR1999]

I use a clamp over the mag base to be sure ti doesn't move. Any movement ofthe indicator will give you false reading and a big headache. Pick a spot to secure it. I like to get the caliper out of the way,hang it by a coat hanger so you only have the bearings to deal with. Set you bearing preload and check the runout. I use ss shim stock and a punch set to shim them. With front rotors you can bolt them together using 3/8-24 flat socket heads then have a shop lightly turn them true. This is if the rotors were changed in the past and the rivets are removed. I can get them down to .001 +/- .0005" with the ss shim stock if you go that route.