Runout?
Thread Starter
Racer
Joined: Sep 2000
Posts: 485
Likes: 1
From: Dallas Texas
Runout?
I have an idea what runout is and know how to check for it and I even have the dial calipers to check on it, but I am unclear as to what it really means. Anyone help this dummy out? :smash:
Thanks
Thanks
Le Mans Master
Joined: Apr 2000
Posts: 5,202
Likes: 10
From: cincinnati ohio
St. Jude Donor '09
Re: Runout? (DVG73)
This may get you started..........
http://www.dippy.org/svcman/sm05i.html#CHECKING
http://www.dippy.org/svcman/sm05i.html#CHECKING
Melting Slicks
Joined: Oct 2001
Posts: 2,064
Likes: 1,382
From: Halifax, Nova Scotia, Canada
Re: Runout? (DVG73)
"What is rotor runout".
It's when the wheel/rotor turns and the rotor, for a lack of a better word, wobbles. In other words "bent", or not running "true".
CAUSE, warped rotor, or bent hub.
RESULT, the wobble in the rotor hits the caliper pistons and pulses them in/out and pumps air into the brake system.
Result, no/poor brakes, pedal to the floor.
ANOTHER CAUSE, is when there is too much "play" in the wheel bearings and causes the same wobble and the same problem.
Use a dial guage to check each rotor. With the dial guage at right angles to the rotor, near the outside edge, rotate the rotor and observe the total amount of "wobble", or runout. More than a few thou will cause brake problems.
THE CURE, If it's only the rotor, replace it. However it could be the hub under the rotor that is the problem.
If so, shim the hub to bring the rotor to within a .001 - .002 runout.
The best cure if it's the spindle flange (hub), is to heve a machine shop true up the flange.
Don't forget to check the wheel bearings for excessive play.
Hope this helps.
Barry
It's when the wheel/rotor turns and the rotor, for a lack of a better word, wobbles. In other words "bent", or not running "true".
CAUSE, warped rotor, or bent hub.
RESULT, the wobble in the rotor hits the caliper pistons and pulses them in/out and pumps air into the brake system.
Result, no/poor brakes, pedal to the floor.
ANOTHER CAUSE, is when there is too much "play" in the wheel bearings and causes the same wobble and the same problem.
Use a dial guage to check each rotor. With the dial guage at right angles to the rotor, near the outside edge, rotate the rotor and observe the total amount of "wobble", or runout. More than a few thou will cause brake problems.
THE CURE, If it's only the rotor, replace it. However it could be the hub under the rotor that is the problem.
If so, shim the hub to bring the rotor to within a .001 - .002 runout.
The best cure if it's the spindle flange (hub), is to heve a machine shop true up the flange.
Don't forget to check the wheel bearings for excessive play.
Hope this helps.
Barry
Tech Contributor
Joined: Aug 1999
Posts: 15,154
Likes: 3,959
From: Connecticut, USA
Re: Runout? (Barry's70LT1)
Barry's has it down pretty good. One thing on the spindle flange runout,I just installed new Tom's spindles and the runout on these is .002" which translates to .005-.006" at the outer edge of the rotor. I had to shim them to bring them in to .001-.002" runout. I really wasn't happy with this but didn't want to press off new bearings and take a big chance of wrecking them.
Gary
Gary
Melting Slicks
Joined: Feb 2000
Posts: 3,052
Likes: 0
From: Vancouver BC, Canada
Re: Runout? (DVG73)
a good idea for shimming:
order a few sets of 1/2" Arbor Shims, .001 or .002 thick, from Reid Tool in MI
shims are precison ground hardened steel, just put them over lug stud between rotor and spindle flange
order a few sets of 1/2" Arbor Shims, .001 or .002 thick, from Reid Tool in MI
shims are precison ground hardened steel, just put them over lug stud between rotor and spindle flange
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: Runout? (DVG73)
IF you remove the spring from behind the pistons, and use O ring pistions/seals you will have no 'runout' problems...UNLESS the runout is .1 inch or so...
about ten times the 'allowable' of a stock spec'd system...
GENE
about ten times the 'allowable' of a stock spec'd system...
GENE
Melting Slicks
Joined: Oct 2001
Posts: 2,064
Likes: 1,382
From: Halifax, Nova Scotia, Canada
Re: Runout? (Turbo-Jet)
I used an old set of feeler guages as shims. Simply cut off the one that is the correct thickness. Feeler guages have the thickness labeled. You can always find the exact one to do the job.
I glued it to the spindle flange so it would stay in the correct location. (Weatherstrip glue)
I glued it to the spindle flange so it would stay in the correct location. (Weatherstrip glue)
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Tech Contributor
Joined: Aug 1999
Posts: 15,154
Likes: 3,959
From: Connecticut, USA
Re: Runout? (Barry's70LT1)
Hey Barry,
I used sheet shim stock and knock punch set. I punched a 7/16" hole and slid the .002" shim over the stud. You can get this stuff at MSC or any industrial supplier.
Gary
I used sheet shim stock and knock punch set. I punched a 7/16" hole and slid the .002" shim over the stud. You can get this stuff at MSC or any industrial supplier.
Gary
