CTS-V1 5x115/120 Conversion Parts/Methods
02-26-2016, 10:04 AM
#1
TECH Resident
Thread Starter
CTS-V1 5x115/120 Conversion Parts/Methods I wrote this up to toss into the files section on my facebook group (https://www.facebook.com/groups/541090912712385/) so I figured I'd toss it up on here for people to search later on. could be useful as a sticky, too.
__________________________________________________ _______________
04-07 CTS-V 5 LUG CONVERSION
There are a few different methods to doing this that range in complexity and cost based on how you want to get it done and what's needed. This can basically be treated as a hub swap, but there is a small amount of machining that needs to be completed regardless of how you want to do it. I will only be explaining methods that allow you do keep a functional parking brake. I do not recommend doing it in a method that does not retain all of the functionality that the car came with stock. If you want to go down that path that is your choice. I know it is a manual car and you can leave it in gear, but we all know that's not the correct thing to do.
Obviously you can increase/decrease cost based on the parts you decide to buy. I used mid-grade hubs (Precision Auto), rotors (OEM replacement Camaro SS rotor from Amazon for front, V2 takeoffs for rear), and added the V2/Camaro SS parking brake assembly. Prior to wheels/tires I spend in the realms of $1200 for everything to do it the "right" way. It's all in what you are comfortable with. I could have done it much cheaper with cheaper parts, but that's not what I wanted on my daily driver.
EDIT: base CTS hubs are a direct swap so you can now use the 5x115 bolt pattern if wanted. This will give you a larger variety of wheel choices that will be in the correct offset and width ranges instead of 5x120/4.75 bolt patterns.
Before I break it all down I'll list the thread where I kept track of what I was doing:
https://ls1tech.com/forums/cadillac-...-complete.html
And now, onto the business...
METHOD 1 (CHEAPEST):
This method you will reuse everything you have on the car, except you'll swap out your stock 6x115 CTS-V hubs for a set of 5x4.75 Corvette C5 hubs that have the same speed/ABS sensor setup built into the hub as we do. You can also use base CTS hubs which are 5x115, the choice is yours. Use the hubs to mark where the new bolt pattern will need to go in the stock rotors and get to drilling. Note that at least one of the holes in the rotors will end up wallowing out one of the stock 6x115 bolt pattern holes. This is totally fine! The rotors are held to the car via friction between the surface of the hub and the wheels, NOT the lug nuts. Don't let anyone tell you this isn't safe because it is. Because we haven't changed the rotors on the rear the stock parking brake is still fully functional.
You also have the choice of running Camaro SS rotors up front here, but the hub bore of the rotors must be opened up from 66.9mm to 70.3mm to fit over the hubs. Not a big deal, but necessary to get it all to work. The hub bore of the base CTS hubs is the same as the stock hubs so you’re good to go there.
Parts necessary:
- Corvette C5 hubs or Base CTS hubs
Modifications necessary with C5 hubs:
- Redrill stock rotors to have 5x120 bolt pattern
- Bore our hub of front rotors from 66.9mm to 70.3mm (only if using Camaro SS rotors in front)
Modifications necessary with base CTS hubs:
- Redrill stock rotors to have 5x115 bolt pattern
METHOD 2-1 (MORE EXPENSIVE):
This method you'll swap out all of the rotors for the appropriate versions. You'll do the same as above with the C5 hubs except we'll have to get some Camaro SS front rotors and V2/Camaro SS rear rotors. From there you'll machine the hub bore of the rotors from 66.9mm to 70.3mm in order to fit them over the hubs. The final piece to this is the V2/Camaro SS parking brake assembly. It's 100% bolt on, but it's just a better design using two pads instead of the stock single horse shoe design that our cars come with. It still needs to be adjusted properly to work well.
I'll list the parking brake assembly parts here:
25814678 - x2, shoe kit
25867413 - x2, shoe lever arm
25867414 - x2, shoe leveler
18K2087 - spring and hardware kit
25851190 - backing plate (driver)
25851205 - backing plate (passenger)
11517996 - x4, bracket nut
Those are GM parts and they're not going to be the cheapest ordering it straight from the dealership. I just wanted it all together and ordered it from Luke at Lindsay Cadillac. You can look around for him on forums and he's dealt with a lot of guys in the past for OEM parts at a not so steep cost straight from a dealer. There's clearly cheaper ways (buying junkyard knuckle assemblies, etc.), but this is what I did. Note that these are not specific to the V2/Camaro SS and are actually on the base CTS from 09-15 as well. It may be on a couple other vehicles as well. That opens up doors.
Parts necessary:
- Corvette C5 hubs or base CTS hubs
- Camaro SS front rotors
- V2/Camaro SS rear rotors
- V2/Camaro SS/CTS(09-15) parking brake assembly
Modifications necessary to have 5x120 bolt pattern:
- Machine rotor hub bore from 66.9mm to 70.3mm
Modifications necessary to have 5x115 bolt pattern:
- Redrill rotors to have 5x115 bolt pattern
METHOD 2-2 (MORE EXPENSIVE):
This method is going to be the same as the one above, except instead of machining the rotors you'll machine the hubs. The hubs have a hub bore OD of 70.3mm and it can be reduced to 66.9mm and rotors will just slip on. This makes it so you can just buy off the shelf rotors when you do your brakes and not worry about it. This is also the method that Creative Steel uses and why buying a set of hubs from them is so expensive. They also make their own parking brake backing plate to use due to cost, but that's neither here nor there.
Parts necessary:
- Corvette C5 hubs or base CTS hubs
- Camaro SS front rotors
- V2/Camaro SS rear rotors
- V2/Camaro SS/CTS(09-15) parking brake assembly
Modifications necessary for 5x120 bolt pattern:
- Machine wheel bearing hub OD from 70.3mm to 66.9mm
Modifications necessary for 5x115 bolt pattern:
- Redrill rotors for 5x115 bolt pattern
METHOD 3 (MOST EXPENSIVE):
This final method is going to be the most expensive option, but that's due to you going with a larger rotor and brake caliper on the front. We're switching to the 6 pot V2 calipers! All of the methods above apply, except in this case we'll need the matching rotors that go with the calipers. The calipers bolt up and fit under the stock 18s if that's something you were curious about as well.
Parts necessary:
- Corvette C5 hubs or base CTS hubs
- V2 front calipers
- V2 front rotors
- V2/Camaro SS rear rotors
- V2/Camaro SS/CTS(09-15) parking brake assembly
Modifications necessary for 5x120 bolt pattern:
- Machine wheel bearing hub OD from 70.3mm to 66.9mm
**OR**
- Machine rotor hub bore from 66.9mm to 70.3mm
Modifications necessary for 5x115 bolt pattern:
- Redrill rotors for 5x115 bolt pattern
This should wrap up all the ways to do it (the right way). Given that you want to skip the parking brake there's easier/cheaper ways to do it, but I like having everything on my car as functional as can be so I have method 2-1 on my car. With wheels and tires I have $2068 in it. Then I sold my stock wheels (with TPMS) for $400 so all in to get to 5 lug with some wheels with specs very close to stock I have $1600 in it. The wheels on the car now are now winter wheels (Wisconsin, yay!) and I'll be running some summer wheels that didn't cost me $4000 to have a custom bolt pattern!
Note that 5x120 wheels will work. The Corvette is 5x4.75, which is 5x120.65 and most wheel manufacturers sell those two patterns as interchangeable. Just be aware of your wheel hub bore and make sure it's larger than 70.3mm and you get hub rings to make up the gap. The same goes with the 5x115 and 5x4.5 (5x114.3) bolt patterns. They’re the same.
__________________________________________________ _______________
04-07 CTS-V 5 LUG CONVERSION
There are a few different methods to doing this that range in complexity and cost based on how you want to get it done and what's needed. This can basically be treated as a hub swap, but there is a small amount of machining that needs to be completed regardless of how you want to do it. I will only be explaining methods that allow you do keep a functional parking brake. I do not recommend doing it in a method that does not retain all of the functionality that the car came with stock. If you want to go down that path that is your choice. I know it is a manual car and you can leave it in gear, but we all know that's not the correct thing to do.
Obviously you can increase/decrease cost based on the parts you decide to buy. I used mid-grade hubs (Precision Auto), rotors (OEM replacement Camaro SS rotor from Amazon for front, V2 takeoffs for rear), and added the V2/Camaro SS parking brake assembly. Prior to wheels/tires I spend in the realms of $1200 for everything to do it the "right" way. It's all in what you are comfortable with. I could have done it much cheaper with cheaper parts, but that's not what I wanted on my daily driver.
EDIT: base CTS hubs are a direct swap so you can now use the 5x115 bolt pattern if wanted. This will give you a larger variety of wheel choices that will be in the correct offset and width ranges instead of 5x120/4.75 bolt patterns.
Before I break it all down I'll list the thread where I kept track of what I was doing:
https://ls1tech.com/forums/cadillac-...-complete.html
And now, onto the business...
METHOD 1 (CHEAPEST):
This method you will reuse everything you have on the car, except you'll swap out your stock 6x115 CTS-V hubs for a set of 5x4.75 Corvette C5 hubs that have the same speed/ABS sensor setup built into the hub as we do. You can also use base CTS hubs which are 5x115, the choice is yours. Use the hubs to mark where the new bolt pattern will need to go in the stock rotors and get to drilling. Note that at least one of the holes in the rotors will end up wallowing out one of the stock 6x115 bolt pattern holes. This is totally fine! The rotors are held to the car via friction between the surface of the hub and the wheels, NOT the lug nuts. Don't let anyone tell you this isn't safe because it is. Because we haven't changed the rotors on the rear the stock parking brake is still fully functional.
You also have the choice of running Camaro SS rotors up front here, but the hub bore of the rotors must be opened up from 66.9mm to 70.3mm to fit over the hubs. Not a big deal, but necessary to get it all to work. The hub bore of the base CTS hubs is the same as the stock hubs so you’re good to go there.
Parts necessary:
- Corvette C5 hubs or Base CTS hubs
Modifications necessary with C5 hubs:
- Redrill stock rotors to have 5x120 bolt pattern
- Bore our hub of front rotors from 66.9mm to 70.3mm (only if using Camaro SS rotors in front)
Modifications necessary with base CTS hubs:
- Redrill stock rotors to have 5x115 bolt pattern
METHOD 2-1 (MORE EXPENSIVE):
This method you'll swap out all of the rotors for the appropriate versions. You'll do the same as above with the C5 hubs except we'll have to get some Camaro SS front rotors and V2/Camaro SS rear rotors. From there you'll machine the hub bore of the rotors from 66.9mm to 70.3mm in order to fit them over the hubs. The final piece to this is the V2/Camaro SS parking brake assembly. It's 100% bolt on, but it's just a better design using two pads instead of the stock single horse shoe design that our cars come with. It still needs to be adjusted properly to work well.
I'll list the parking brake assembly parts here:
25814678 - x2, shoe kit
25867413 - x2, shoe lever arm
25867414 - x2, shoe leveler
18K2087 - spring and hardware kit
25851190 - backing plate (driver)
25851205 - backing plate (passenger)
11517996 - x4, bracket nut
Those are GM parts and they're not going to be the cheapest ordering it straight from the dealership. I just wanted it all together and ordered it from Luke at Lindsay Cadillac. You can look around for him on forums and he's dealt with a lot of guys in the past for OEM parts at a not so steep cost straight from a dealer. There's clearly cheaper ways (buying junkyard knuckle assemblies, etc.), but this is what I did. Note that these are not specific to the V2/Camaro SS and are actually on the base CTS from 09-15 as well. It may be on a couple other vehicles as well. That opens up doors.
Parts necessary:
- Corvette C5 hubs or base CTS hubs
- Camaro SS front rotors
- V2/Camaro SS rear rotors
- V2/Camaro SS/CTS(09-15) parking brake assembly
Modifications necessary to have 5x120 bolt pattern:
- Machine rotor hub bore from 66.9mm to 70.3mm
Modifications necessary to have 5x115 bolt pattern:
- Redrill rotors to have 5x115 bolt pattern
METHOD 2-2 (MORE EXPENSIVE):
This method is going to be the same as the one above, except instead of machining the rotors you'll machine the hubs. The hubs have a hub bore OD of 70.3mm and it can be reduced to 66.9mm and rotors will just slip on. This makes it so you can just buy off the shelf rotors when you do your brakes and not worry about it. This is also the method that Creative Steel uses and why buying a set of hubs from them is so expensive. They also make their own parking brake backing plate to use due to cost, but that's neither here nor there.
Parts necessary:
- Corvette C5 hubs or base CTS hubs
- Camaro SS front rotors
- V2/Camaro SS rear rotors
- V2/Camaro SS/CTS(09-15) parking brake assembly
Modifications necessary for 5x120 bolt pattern:
- Machine wheel bearing hub OD from 70.3mm to 66.9mm
Modifications necessary for 5x115 bolt pattern:
- Redrill rotors for 5x115 bolt pattern
METHOD 3 (MOST EXPENSIVE):
This final method is going to be the most expensive option, but that's due to you going with a larger rotor and brake caliper on the front. We're switching to the 6 pot V2 calipers! All of the methods above apply, except in this case we'll need the matching rotors that go with the calipers. The calipers bolt up and fit under the stock 18s if that's something you were curious about as well.
Parts necessary:
- Corvette C5 hubs or base CTS hubs
- V2 front calipers
- V2 front rotors
- V2/Camaro SS rear rotors
- V2/Camaro SS/CTS(09-15) parking brake assembly
Modifications necessary for 5x120 bolt pattern:
- Machine wheel bearing hub OD from 70.3mm to 66.9mm
**OR**
- Machine rotor hub bore from 66.9mm to 70.3mm
Modifications necessary for 5x115 bolt pattern:
- Redrill rotors for 5x115 bolt pattern
This should wrap up all the ways to do it (the right way). Given that you want to skip the parking brake there's easier/cheaper ways to do it, but I like having everything on my car as functional as can be so I have method 2-1 on my car. With wheels and tires I have $2068 in it. Then I sold my stock wheels (with TPMS) for $400 so all in to get to 5 lug with some wheels with specs very close to stock I have $1600 in it. The wheels on the car now are now winter wheels (Wisconsin, yay!) and I'll be running some summer wheels that didn't cost me $4000 to have a custom bolt pattern!
Note that 5x120 wheels will work. The Corvette is 5x4.75, which is 5x120.65 and most wheel manufacturers sell those two patterns as interchangeable. Just be aware of your wheel hub bore and make sure it's larger than 70.3mm and you get hub rings to make up the gap. The same goes with the 5x115 and 5x4.5 (5x114.3) bolt patterns. They’re the same.
Last edited by Bio248; 10-12-2016 at 04:04 PM.
02-26-2016, 10:19 AM
#2
Nice writeup.
I went with skf front hubs from a 07 Zo6 and normal Zo6 hubs for the rear. Upgraded to v2 rear ebrake with v2 2-pc slotted rotors upfront and v2 1-pc slotted rear
Next upgrade is the z28 ccm brake system, but i want to be able to swap between the two...
I went with skf front hubs from a 07 Zo6 and normal Zo6 hubs for the rear. Upgraded to v2 rear ebrake with v2 2-pc slotted rotors upfront and v2 1-pc slotted rear
Next upgrade is the z28 ccm brake system, but i want to be able to swap between the two...
02-26-2016, 10:33 AM
#3
TECH Resident
Thread Starter
as stated in the past i was doing mine for mainly aesthetic reasons since i just wanted different wheels on the car, but it would make sense to do this to be able to run other brake setups as you've mentioned.
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54inches (05-11-2022)
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54inches (05-11-2022)
04-16-2016, 01:38 AM
#11
On The Tree
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Has anyone tried the hurst 2 piece rotors for the camaros? The mustang guys seem to love them and the price is hard to beat. They sell fronts and rears.
http://www.hurst-shifters.com/produc...yr=&md=&sm=&e=
http://www.hurst-shifters.com/produc...yr=&md=&sm=&e=
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54inches (05-11-2022)
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54inches (05-11-2022)
04-16-2016, 08:58 AM
#16
TECH Regular
If you can show me, why it won't work on technical side, I will believe you that it's a bad idea doing this, otherwise not!
Regards,
Ronald
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54inches (05-11-2022)
04-16-2016, 10:05 AM
#18
Gamble with your life,
The biggest problem you're going to run into is being able to find a clean area for all your new spindles to fit. iyou need an area without having any interference from the original spindle holes, if you can do that then great but chances are you will have overlap between one of the old spindle locations and with your new spindle locations so like I said before gamble with your life not with others
The biggest problem you're going to run into is being able to find a clean area for all your new spindles to fit. iyou need an area without having any interference from the original spindle holes, if you can do that then great but chances are you will have overlap between one of the old spindle locations and with your new spindle locations so like I said before gamble with your life not with others
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54inches (05-11-2022)
04-16-2016, 10:31 AM
#19
TECH Regular
Ok, that's the only reason I see now before I tried it, as I said in my first post here, I will make a drawing 1:1 and then see if it will work and where and how much overlap there is, then I will post the results, thank u!
04-16-2016, 12:05 PM
#20
The reason that it is a stupid and horrible idea is that you are compromising how the wheel lugs attach to the hub and the lugs are the only thing that hold the wheels to the car. Any overlap or any lug hole that is within a 1/4-1/2" of an existing lug hole would be greatly compromised.
Now people have been redrilling 5x4.5 and 5X4.75 hubs and axles forever without any problems but that is only because the lugs are evenly spaced between the existing holes. You can even look at the Creative Steel 5 Lug Swap and see that they have taken the stock c5 corvette hub which is 5x4.75 and redrilled them to 5x120mm but it is a non issue as they are also evenly spaced between the existing lug holes.
Go on ebay and spend $120 on a set for four c5 corvette hubs and save yourself the time and possible death from a fiery crash due to your wheels falling off from redilling the stock 6x115mm hubs.