Disclaimer
The community here at 355nation.net urges you to please use caution and seek professional assistance when performing modifications to your vehicle. Before attempting any modification it is advised that you refer to your Colorado or Canyon service manual or contact a certified mechanic as not all GMT355 trucks are the same. The staff and the associated members are in no way responsible for any damages, injuries or other harm inflicted to your vehicle or yourself which may result in attempting these modifications. The posts and content presented on this site reflect in no way the views of 355nation.net or it’s ownership.
A 355nation How To presented by
burn
Project Description
Bore aluminum wheels
Skill Level
Advanced
Project Vehicle
Make: Chevrolet
Model: Colorado
Year: 2006
Engine: 3.5L
Transmission: Auto
Power windows: No
Sun Roof: No
Please be aware that although this is a fairly straight-forward process, its very easy to damage a rim beyond repair. I infact screwed up while boring out the first rim - but by learning from my mistakes was able to bore out the other 3 wheels flawlessly. I was able to salvage the first rim that I screwed up on by over-boring the hole. This left me with 1 wheel that the bore depth is 11/16" whereas the other 3 wheels have a bore depth of 1/2". It will have no impact on the usability of the wheel, it will just be a few grams lighter than the other 3. The shop I got these from are giving me a 5th wheel for free as compensation for having to go through this. I will bore the 5th wheel correctly then keep the buggered wheel in the attic in case I bust a wheel on a pot-hole.
Anyways, moving on........
I picked up a set of RTX Blackhawk 20x8.5" wheels. The RTX wheel search said that these wheels would fit, but when I got them in I found that the centre bore was too small. It was only 75mm:
The stock bore on the Colly is 101mm. I have marked out what 101mm would look like:
I picked up a Freud rabbiting bit. It will cut up to 1/2" width, as well as 1/2" depth. It has different bearings that you can swap out on the tip to give you different width's. I had to use the smallest bearing to give the widest cut of 1/2":
Back of the packaging for the model number incase you want to get the same one. I got this from Home Depot for $38:
Be sure to use lots of WD-40 to keep the bit lubricated while cutting:
I figured out (after screwing up on the first wheel) that its best to cut the bore in 2 steps. Set the bit in at half-dept to cut out the first 1/4":
Then put the rim face down on some carpet, and slowly & carefuly work your way around the opening, gradually opening it up. The bearing will limit you so you cant cut the width beyond 1/2" more than the stock bore. Just keep going until it stops cutting:
Here is a finished wheel bored to 101mm (4"), cut 1/4" deep:
Then adjust the router to give the full 1/2" deep cut:
Now this is the rim that got screwed up - but I was able to salvage it. The bore in the top half of the pic is cut to the full depth, and the bottom half of the bore is nearly complete. You just have to keep whittling it down:
Once its all done, you can measure the bore and will find that they are all now the necessary 101mm bore:
And when you are all done cleaning up you will have a snazzy shop-vac full of aluminum shavings!:
Any questions - post em up!
The community here at 355nation.net urges you to please use caution and seek professional assistance when performing modifications to your vehicle. Before attempting any modification it is advised that you refer to your Colorado or Canyon service manual or contact a certified mechanic as not all GMT355 trucks are the same. The staff and the associated members are in no way responsible for any damages, injuries or other harm inflicted to your vehicle or yourself which may result in attempting these modifications. The posts and content presented on this site reflect in no way the views of 355nation.net or it’s ownership.

A 355nation How To presented by
burn
Project Description
Bore aluminum wheels
Skill Level
Advanced
Project Vehicle
Make: Chevrolet
Model: Colorado
Year: 2006
Engine: 3.5L
Transmission: Auto
Power windows: No
Sun Roof: No
Please be aware that although this is a fairly straight-forward process, its very easy to damage a rim beyond repair. I infact screwed up while boring out the first rim - but by learning from my mistakes was able to bore out the other 3 wheels flawlessly. I was able to salvage the first rim that I screwed up on by over-boring the hole. This left me with 1 wheel that the bore depth is 11/16" whereas the other 3 wheels have a bore depth of 1/2". It will have no impact on the usability of the wheel, it will just be a few grams lighter than the other 3. The shop I got these from are giving me a 5th wheel for free as compensation for having to go through this. I will bore the 5th wheel correctly then keep the buggered wheel in the attic in case I bust a wheel on a pot-hole.
Anyways, moving on........
I picked up a set of RTX Blackhawk 20x8.5" wheels. The RTX wheel search said that these wheels would fit, but when I got them in I found that the centre bore was too small. It was only 75mm:

The stock bore on the Colly is 101mm. I have marked out what 101mm would look like:

I picked up a Freud rabbiting bit. It will cut up to 1/2" width, as well as 1/2" depth. It has different bearings that you can swap out on the tip to give you different width's. I had to use the smallest bearing to give the widest cut of 1/2":

Back of the packaging for the model number incase you want to get the same one. I got this from Home Depot for $38:

Be sure to use lots of WD-40 to keep the bit lubricated while cutting:

I figured out (after screwing up on the first wheel) that its best to cut the bore in 2 steps. Set the bit in at half-dept to cut out the first 1/4":

Then put the rim face down on some carpet, and slowly & carefuly work your way around the opening, gradually opening it up. The bearing will limit you so you cant cut the width beyond 1/2" more than the stock bore. Just keep going until it stops cutting:

Here is a finished wheel bored to 101mm (4"), cut 1/4" deep:

Then adjust the router to give the full 1/2" deep cut:

Now this is the rim that got screwed up - but I was able to salvage it. The bore in the top half of the pic is cut to the full depth, and the bottom half of the bore is nearly complete. You just have to keep whittling it down:

Once its all done, you can measure the bore and will find that they are all now the necessary 101mm bore:

And when you are all done cleaning up you will have a snazzy shop-vac full of aluminum shavings!:

Any questions - post em up!