redrilling axles and hubs - help and guidance???

[Chuck78]

I've got a nice set of 5 on 5 torque thrust d's for my 62 GMC panel truck, and want to swap out the non-fitting wheels that are on it now (6 lug) asap. I'll probably pay to have the GMC Dana 44 rear end redrilled ($100 @ Babbit Bearing locally), but I was thinking I might try and do the fronts myself since I will eventually be swapping to a 73-87 front end with discs. I need some help and advice on how to get the pattern set up right. I have a drill press, can use a factory wheel, and have some factory rotors, but I still don't know exactly how I am going to get this pattern 100% accurate on the old hubs/drums up front. I wish I had a template with 3/16" holes to use as a guide, so that the big drill bit doesn't walk around at all when I take the plunge with that. Only get one chance!

House remodel and power steering are the bigger priorities than a disc swap, as I can get by on the drums now, but the manual steering and lack of a sway bar is definitely becoming a drag.

Thanks,

Chuck

[PrerunnerRob]

I am a machinist by no means, but couldnt you get the distance from the centerfor the hole, divide 360 by 5 (72 degrees) and get the number of degrees to rotate the rotor per hole? I would really suggest taking everything to a machine shop, and make sure there is enough meat in the drum to accomodate the new hole. Take a look at the rear of the drum to make sure it can accomodate a stud.

[Captainfab]

If you either have or can find a 5 hole wheel that fits the center of the hub snugly, simply use a transfer punch to mark your holes. Then just drill a pilot hole and then your final hole size for the studs you are going to use.

Here's what transfer punches are in case you don't know. You just need the correct size to fit the lug hole in the wheel you use for the pattern. Most industrial supplies will sell single sizes and are typically of higher quality than what can be found at HF.

http://www.harborfreight.com/cpi/cta...temnumber=3577

http://www.rlspellmanmfg.com/index_punches.html

[Fred T]

I agree that this is a job best left to a machine shop. The location of the studs in relation to the axle center needs to be closer than most people can do with a drill press. If I were doing it myself I would set up on an end mill where it is far easier to keep a hole on center.

Another issue is that there are two holes that will need to be plugged. The best solution is to leave the studs in place and grind the stud flush on both sides. The plug then needs to be fixed. I would tack weld with a MIG.

I have attached a pattern showing the conversion. Outer pattern is 6 X 5.5, inner is 5 X 5. If you want to try doing this yourself, print on card stock. Measure the diameter of one of the large circles to check your print, many printers are not accurate and will need some resizing of the plot.