"Hammer clearancing" for wheels?
Registered User
Joined: May 2001
Posts: 2,534
From: Northwest GA
Originally posted by Brent94Z
My buddy has 33" tall tires on his SS
My buddy has 33" tall tires on his SS
OK, so that's a bit exxagerated, and I deleted a few words from your original reply, but I was dying to post that pic somewhere...
See Jason - anything is possible with your Camaro!
Last edited by 94BlackBowtie; Apr 28, 2003 at 12:51 PM.
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Joined: May 1999
Posts: 4,060
From: Inverness, FL
Originally posted by JDHarris
Okay, so I stand corrected. I was going off of something I'd read here previously. Sorry for the misinformation.
Okay, so I stand corrected. I was going off of something I'd read here previously. Sorry for the misinformation.
Registered User
Joined: May 2002
Posts: 393
From: Roanoke, VA
I might have read it wrong but you are trying to roll the fenders, right? I've heard using a bat works great and it doesn't look like it was "hammered". Here is the way I did mine...
put the stock tires/rims back on.
place a bat on the side of the wheel (fat head on the fenders)
then move the car slowly and pull on the bat. the fat head of the bat should now be "rolling" against the fender pushing it out giving you more clearance. repeat this process until you are happy with the results.
you will not notice any marks, lines, hammer smacks, or any peeling. good luck!
put the stock tires/rims back on.
place a bat on the side of the wheel (fat head on the fenders)
then move the car slowly and pull on the bat. the fat head of the bat should now be "rolling" against the fender pushing it out giving you more clearance. repeat this process until you are happy with the results.
you will not notice any marks, lines, hammer smacks, or any peeling. good luck!
Thread Starter
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Joined: Dec 1997
Posts: 11,157
From: Nashville, TN area
Originally posted by White Z 4 Show
I might have read it wrong but you are trying to roll the fenders, right?
I might have read it wrong but you are trying to roll the fenders, right?
Thanks for the info anyway!
Hopefully it doesn't have to come in handy in the future! 
Registered User
Joined: May 2000
Posts: 2,889
From: Peachtree City, GA
i had same problem when i put my y2k vette wheels on..they were OEM GM wheels...front fit fine, but for the back i had to use little hammer action Just bang the hell out of it and paint it black after you are done..you will hardly see it
Marcin
Just bang the hell out of it and paint it black after you are done..you will hardly see it Marcin
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Joined: Nov 1998
Posts: 71,114
From: Hell was full so they sent me to NJ
The chart I have from the April 2002 issue of VETTE magazine indicates the Z06 18x10.5 wheels are 58mm offset, in BOTH GM and repro models. That means you have roughly an 8.00" backspace, or somewhere between 1/16" and 1/8" tighter (closer to the inner fender sheet metal) than the "GS offset" 17x11's (7.93" BS). It's got to be very tight.
You only tried one wheel. Try the other one also. I'm assuming you did this with the rear axle loaded, so the tire would be sitting at normal ride height. If you had the axle at full drop, the movement of the Panhard rod throws the side-to-side location of the axle off. And, even if you had the rear suspension loaded, the car might not be perfectly centered over the rear axle. Try it with both wheels on the car, and with the axle loaded. That will tell you if some clearance might be gained on one side with an adjustable panhard rod.
You also need to look at the projecting corners of the jounce bumper brackets. Most likely they stick well within the inner diameter of the wheel, and if you let the axle go to full drop, the bracket is going to catch the inside of the wheel and scrape it up.
I found with the 7.93" BS wheels that I had to:
1 - Hammer the inner fenders. I used a 3# hammer and was very aggressive. As noted above, you won't damage the structural integrity of the car. At that point most of the strength is in the subframes, and not much in the fender well sheet metal. The big "gotcha" is to keep the seat back in position, so you don't risk distorting the metal around the pin that the seat back latches to. After I got done with the hammering, I used a spray can of rubberized undercoat. It looks decent, because the undercoat is "flat" and doesn't emphasize the dings, but they are still there and you can tell it was hammered. I also knew I would be running 28" slicks, so I hammered it more than you might have to.
Sheet Metal Rampage
2 - I hacked the jounce bumper brackets off flush. They won't catch the wheel in "normal" driving, specially if your car is lowered, but if you jack it and forget it, you well scrape the wheels.
Jounce Bumper Carnage
3 - When I got all done, there was less clearance on one side and more on the other side. I used my adjustable panhard rod to move the body about 1/8" to get things "even". Note that all of this is on a stock ride height car... or maybe even 1/4 to 1/2" above stock, because of the drag launch springs and air bags.
Clearance - drivers side from rear
Clearance - passenger side from rear
Clearance - looking straight up from floor into wheel well
Note that "corner" that is coming down from the top of the last photo.... that is the passenger side, and the point is a VERY heavily reinforced area... there is a "box" section behind it. It takes a BFH to bend that part back.
End results
Since you have a wheel that sticks back 1/16 to 1/8" deeper into the wheel well, its hard to see how you can have anything but a more difficult time than I had. The outside edge of your wheels/tires will also be about 0.60" deeper into the wheel well than what you see in the picture above. That would indicate to me that the best solution would be a very thin spacer. I would almost say 1/4" max. Get a quality spacer, and be sure the hub studs are long enough to put the ends of the studs at least 1/2" outside the conical surface of the wheel mounting hole. (See tech discussion on "wheel spacers" on Advanced Tech"). Be sure to use a torque wrench to tighten the lugs in a "star" pattern. Take them up to 60ft-lb, then 80ft-lb, then 100ft-lb. May sound ****, but it works.
And, whenever I post this info, someone will post that they have the exact same wheels and tires, and didn't have to do anything. So it appears NOT all F-Bodys are created equal.
You only tried one wheel. Try the other one also. I'm assuming you did this with the rear axle loaded, so the tire would be sitting at normal ride height. If you had the axle at full drop, the movement of the Panhard rod throws the side-to-side location of the axle off. And, even if you had the rear suspension loaded, the car might not be perfectly centered over the rear axle. Try it with both wheels on the car, and with the axle loaded. That will tell you if some clearance might be gained on one side with an adjustable panhard rod.
You also need to look at the projecting corners of the jounce bumper brackets. Most likely they stick well within the inner diameter of the wheel, and if you let the axle go to full drop, the bracket is going to catch the inside of the wheel and scrape it up.
I found with the 7.93" BS wheels that I had to:
1 - Hammer the inner fenders. I used a 3# hammer and was very aggressive. As noted above, you won't damage the structural integrity of the car. At that point most of the strength is in the subframes, and not much in the fender well sheet metal. The big "gotcha" is to keep the seat back in position, so you don't risk distorting the metal around the pin that the seat back latches to. After I got done with the hammering, I used a spray can of rubberized undercoat. It looks decent, because the undercoat is "flat" and doesn't emphasize the dings, but they are still there and you can tell it was hammered. I also knew I would be running 28" slicks, so I hammered it more than you might have to.
Sheet Metal Rampage
2 - I hacked the jounce bumper brackets off flush. They won't catch the wheel in "normal" driving, specially if your car is lowered, but if you jack it and forget it, you well scrape the wheels.
Jounce Bumper Carnage
3 - When I got all done, there was less clearance on one side and more on the other side. I used my adjustable panhard rod to move the body about 1/8" to get things "even". Note that all of this is on a stock ride height car... or maybe even 1/4 to 1/2" above stock, because of the drag launch springs and air bags.
Clearance - drivers side from rear
Clearance - passenger side from rear
Clearance - looking straight up from floor into wheel well
Note that "corner" that is coming down from the top of the last photo.... that is the passenger side, and the point is a VERY heavily reinforced area... there is a "box" section behind it. It takes a BFH to bend that part back.
End results
Since you have a wheel that sticks back 1/16 to 1/8" deeper into the wheel well, its hard to see how you can have anything but a more difficult time than I had. The outside edge of your wheels/tires will also be about 0.60" deeper into the wheel well than what you see in the picture above. That would indicate to me that the best solution would be a very thin spacer. I would almost say 1/4" max. Get a quality spacer, and be sure the hub studs are long enough to put the ends of the studs at least 1/2" outside the conical surface of the wheel mounting hole. (See tech discussion on "wheel spacers" on Advanced Tech"). Be sure to use a torque wrench to tighten the lugs in a "star" pattern. Take them up to 60ft-lb, then 80ft-lb, then 100ft-lb. May sound ****, but it works.
And, whenever I post this info, someone will post that they have the exact same wheels and tires, and didn't have to do anything. So it appears NOT all F-Bodys are created equal.
Last edited by Injuneer; Apr 28, 2003 at 10:29 PM.
Registered User
Joined: Sep 2003
Posts: 5,907
From: The Wild West
Re: "Hammer clearancing" for wheels?
Great information gentlemen. I seached Vette forums all night last night trying to find the offset for stock Z06's and of course CamaroZ28 has it. I think this will come in handy fitting similar GM Z06 wheels. Thanks fella's, time to find some wheels and persuade my wheel wells to like the 18x10.5's
-Dustin-
-Dustin-
Registered User
Joined: Aug 1998
Posts: 520
From: Perryopolis, Pa
Re: "Hammer clearancing" for wheels?
If you are hammering in the wheel well, try using a small 4x4 block of wood. Press the side of the block against the inner & hit that with a hammer. This way you get a smooth deflection with no hammer marks.
Remember the stiff 18" tire will not deflect much. I drive my Camaro w/ only space for my little finger & 315 Drag Radials. It only hits if I corner hard w/ low air pressure. Stiff 18 have less sidewayy & should deflect less.
Also 1/8" spacers are not bad. You can get steel ones from GM. They used them on the Formula Firebirds w/ WS6 in the late 80's-early 90's on the rears with drum brakes. If they were safe enough for GM, I would not worry.
Remember the stiff 18" tire will not deflect much. I drive my Camaro w/ only space for my little finger & 315 Drag Radials. It only hits if I corner hard w/ low air pressure. Stiff 18 have less sidewayy & should deflect less.
Also 1/8" spacers are not bad. You can get steel ones from GM. They used them on the Formula Firebirds w/ WS6 in the late 80's-early 90's on the rears with drum brakes. If they were safe enough for GM, I would not worry.
Registered User
Joined: May 2003
Posts: 1,132
From: Atlanta Ga
Re: "Hammer clearancing" for wheels?
I use 17x11's all the way around and I too had to hammer that area of the wheelwell. It's a VERY sound part of the car and takes a considerable amount of pounding to make much of a dent at all.
I use and would recommend a 1/4" spacer. You can get a billet aluminum hub centric spacer from www.wheeladapters.com , that's where I got mine. They're not cheap at $40 each but you're not looking for cheap, you want it right.
It's possible you might need to get longer studs. On the LT1 cars, the front studs are 1/4" longer and I used those in the rear. You don't even have to pull the axles to put them in.
I use and would recommend a 1/4" spacer. You can get a billet aluminum hub centric spacer from www.wheeladapters.com , that's where I got mine. They're not cheap at $40 each but you're not looking for cheap, you want it right.
It's possible you might need to get longer studs. On the LT1 cars, the front studs are 1/4" longer and I used those in the rear. You don't even have to pull the axles to put them in.