Redrill your own axles

[coilover]

Have noted several posts on changing bolt patterns to five lug on a six lug rear or to six lug on a five lug rear end or bolt circle sizes. This usually comes up when a front end is changed to A-frame type or rear to an open driveshaft. I am getting my 37 Buick ready for the AACA annual Bug Tussle Trek (big in the northern part of Texas) and with a brand new engine I didn't want to keep the 4.44 factory gears. Four dollar gas is also a factor. I could have used the Bridgeport mill and an index table but decided to try it with tools the hobbiest either has or can get at the local Home Depot. If your lucky your new wheel will fit the axle pilot tight (I wasn't). If not, first use a wheel with the bolt pattern you want and one that has a center pilot hole that is too big; a "white spoke" painted wheel has a big pilot hole no matter what the bolt pattern is. Make a bushing (on any home wood lathe) that fits tight on the axle pilot and tight in the wheel center. This is the yellowish colored ring in the center of the wheel in the picture. Now get a short pipe nipple that the OD fits the lug bolt hole in the wheel and a drill bit that fits inside the nipple, you may have to drill it through. This will keep your drill from walking off center. After drilling with this bit you can enlarge to the size of the shoulder of the lug bolt your using and draw it through the axle with a lug nut, washers, and a smear of anti sieze. This drills the axle and brake drum in one operation. Buick had lug bolts instead of lug nuts so I drilled and tapped the axle flange. The tire has virtually no run out.

 

[Kens 50 PU]

I think I know what you're talking about, but I need a little more information. Can you describe (with pictures) a little more about the drilling process and what you do as far as the drums themselves. Can you take an 8 lug axle and convert it to 5 or 6?

 

[Chiro]

And if converting a five lug modern bolt pattern to six lug as when changing out the rear end, will there be any overlap of bolt holes to worry about? How does one secure the "template wheel" used to line up the new bolt holes when converting a five lug modern rear to six lug bolt pattern?

I DO like it. Could save probably about $150.00 or more and LOTS of down time for the vehicle waiting for the machine shop to redrill the axles on a closed to open driveline conversion.

Andy

 

[coilover]

First an answer for Andy; you drill the first hole and put a lug in and snug the nut down. This holds the wheel while drilling the remaining holes. If some of the old holes overlap the new pattern I tap the old lug holes with the smallest tap that will thread the holes left after the original lugs are hammered out. It usually take drilling to make the holes the right size for the tap. I then use RED loctite on a grade five bolt, thread it in till flush with the back, and cut off flush with the outer flange. This is plenty strong and doesn't make welding hard spots which often make a drill walk off center.
The pics are for Ken. The first shows the old pattern (white) and the new pattern(orange). The next shows how much bigger the center hole in the wheel was than the axle pilot. The last shows the spacer ring made to hole the wheel exactly on center. Once the wheel is so mounted then a short piece of tubing that just fits the lug hole in the wheel is used along with a drill that just fits the hole in the center of that tubing is used to make a pilot hole through both the brake drum and axle flange which can later be enlarged to the size of the shoulder on the new lug bolt. This is shown, with a drill in the tubing and the spacer ring in place, on the first posting picture (above). Remember, it is the pilot that centers a wheel not the lug nuts, they just hold it on.