Change Bolt Pattern???

[M1A1TankerTom]

Hey guys, on my 62 truck I have 5x5 bolt pattern. I just picked up a sweet set of rally wheels but they are 5X4.75 bolt pattern. Is there a way I could enlarge the holes on the 5X4.75 wheels so that they would fit my 5X5 pattern? I had a idea that if I just ground the holes out a little they would work fine. Then again I was drinking when I thought of that....what do you guys think?

[steverino66]

I briefly considered re-drilling my 6-lug hubs for 5 on 5, but was talked out of doing so by wiser brains, including a machinist.
Anything that could make your hubs/wheels less than 100% tight and stable could cause you bad vibrations, possibly to lose wheel studs or a wheel at some point. These are pretty heavy trucks.

[ryan913]

It is very dangerous to do this to stamped steal wheels. They have a chamfer that the lug nut seats into and if you open up the hole, the nut will not seat properly causing stress, that leads to metal fatigue, that leads to failure. I would advise you not to do it.

[greg64]

From an engineering perspective, I think you'd be nuts to drill out the holes. Besides unintentional weakening, on many wheels (those that use tapered nuts) the holes provide the centering.

You could probably swap the rotors and axles and end up where you need to be, or alternatively, sell the wheels and buy the same style with 5 on 5.

I just can't see a good way to modify the parts you have.

[olsofti]

Don't do the wheels! You would end up with a bad accident waiting to happen.
However you could drill the rotors to the 4 3/4 pattern and replace the studs.Some people don't like this either,but I've seen it done before.
I tried to find front rotors with that pattern but didn't have any luck.

[M1A1TankerTom]

damn! Im gonna have to quit thinking about my truck while I drink. Thanks for all the help guys.

[502tripower]

Originally Posted by greg64

You could probably swap the rotors and axles and end up where you need to be, or alternatively, sell the wheels and buy the same style with 5 on 5.

The first part of this statement is not an option. There is no one that makes a rotor with a 5X4-3/4 GM passenger car bolt pattern that will work with the light duty truck spindle. The later is your best option.

Originally Posted by olsofti

Don't do the wheels! You would end up with a bad accident waiting to happen.

However you could drill the rotors to the 4 3/4 pattern and replace the studs.Some people don't like this either,but I've seen it done before.
I tried to find front rotors with that pattern but didn't have any luck.

This is an option but can jeopardize the integrity of the rotor. I have seen this done but, instead of using a regular knurled panhead type stud I would suggest using a grade #8 allen head stud. The reason for this is the casting on the back of the rotor has 5 raised areas that will have to me machined in order to allow for the new studs. This is the area that I mentioned earlier that could jeopardize the integrity of the rotor. By using the grade #8 allen screw stud you can drill a smaller hole, as there is no knurl, then tap the hole to the thread pitch of the allen screw. Also the raised casting on the back of the rotor will require less material removed for the smaller head of the allen screw stud. Apply a little bit of locktite when installing the allen screw studs and your done. On another note. You will have to repeat this process if ever the rotors need replacing or updating. Something to think about if on a road trip and a rotor fails.