rotor redrill help needed

[dusterbd13]

so im getting ready to start on my 4 wheel disc conversion.

the rear disc setup im using is a leftover from another project, therefore it has the wrng wheel bolt pattern. i plan on redrilling this. the rest of the setup will work fine, just the wheel bolt pattern in the rotor hat is wrong.
first, is there any reason i shouldnt redrill it? second, could someone do me a cad template or somethinng to go by? current pattern is 5X4.5, and i neeed to go to 5X4.75
i was thinking if i could get a template, i could glue it to some wood, drill the old pattern so i could bolt through it to the rotors, and then center punch and redrill the new pattern. sound like it will work? it does in my head...
Michael

[astroracer]

Get an old drum brake or axle. An old axle would be best. Make sure your rotor fits the hub and use the axle as your drilling template. Use a transfer punch to get a good center mark to start drilling and make sure you have the right size drill for lug stud knurl retention.
Mark

[csouth]

Also if you don't have an old axle, Moser sells the bolt pattern template.

[Apogee]

Is the rotor hub-centric? If so, the hole pattern isn't all that critical since rotor centering is handled by the center bore, not the wheel stud holes. It can look a little funky, but running a drill that is +1/4" larger though the holes where they are will give you what you need and not require any additional fuss or muss.

Tobin
KORE3

[dusterbd13]

thanks, tobin!!!

now to see just how hubcentric they are. heres to hoping.....

[chevnut55]

I just ran into this problem, my hub is smaller than the rotor so there is play and Im having a hard time to get it all centered. any tricks to fix this problem?

[Apogee]

I just ran into this problem, my hub is smaller than the rotor so there is play and Im having a hard time to get it all centered. any tricks to fix this problem?

Buy or machine a hub-centric ring matching the OD of the axle register and the ID of the rotor. Alternatively, you could sleeve the register to make it larger by machining a ring, heating it, and slipping it on so that it's a semi-permanent solution rather than a loose spacer ring.

Tobin
KORE3

[chevnut55]

Thanks, I look to see if anyone sell one before I rip everything apart. the c5 brake kit fit and works great by the way.

[Skip Fix]

My new axles the rotor was hubcentric but some of the studs very not perfectly straight to the rotor would not slide on until I tewaked them some.Same cane be for lugnuts in the wheel if they are tight for being lugcentric. One of my Mosers on the Camaros drag car is that way one stud is not perfectly centered and barely goes in.

[novaderrik]

might be easier to just find a car with the proper bolt pattern that uses a rotor that is similar to the one you have now..

what is the original application of the rotor, and what are you putting it on?

[chevnut55]

Ok, I took everything apart to check any problems, the rotor fits the hub, the studs are a bit off but probly straighten out when tightened to the wheel.
I made a spacer ring from a cut hose clam so it fight tight and the wheels still seem so vibrate and bounce , there is around 1/8" movement.. I do not understand this as I have done all this stuff before and never seen a problem like it.

[Apogee]

...there is around 1/8" movement.. I do not understand this as I have done all this stuff before and never seen a problem like it.

There is around 1/8" of movement where?

Tobin
KORE3

[chevnut55]

If I put in gear jacked up and place a board under the tires just about touching I can see the space change around 1/8. almost like the rims are oval but they are balanced.

[SSLance]

By chance is the axle bent? You should do the same test only watching the end of the axle for movement.

[chevnut55]

Its both rear tires on a rebuilt rear with new axles...but I will check anyway, thanks

[Skip Fix]

Is the hub locating the wheel or the lugnuts? Most aftermarket axle hubs are too short to locate the wheel if you have a rotor on them esp Moser's. Some aftermarket wheels the hub hole is bigger than the hib-there are hubcentirc precision made rings for that.

If the lug nuts are all that are locating the wheel not the hub I'll bet there is enough difference in the lug nut OD and the wheel lug hole ID to let the wheel move and get tightened slightly off center.

[rod cole]

Tires are not perfectly round you need to measure or watch the wheel itself. Wheels are usually pretty true Tires not so much. That is why road force balancing was invented to measure tire out of roundness and help match the wheel tire combo better.