"Hammer clearancing" for wheels?

Well, things sure do suck when it comes to me and wheels.

Today I put on one of my genuine GM Z06 wheels/tires on the rear driver side to see how it fits, and they does not clear the 9:30-10:00 area on the driver side inner wheel well. I believe this would be the case regardless of drop springs or not. For the record, I mention these are genuine GM Z06 wheels because I belive replicas have a different offset and do not have this problem on our cars.

Then I put on a 1/8" spacer that I had laying around and tried again just to see what would happen.

It is VERY VERY snug, I can't even get my little finger in between the tire and the inner wheel well, and there may even be a tighter spot that I cannot see or reach.

So, I think my only resort is to hammer clearance the inner fenderwell where it is tight. I am not sure if I want to resort to that, but I don't like the idea of using wheel spacers.

So, it is either sell these wheels/tires :( or buy a nice hammer and start making some room.

I am sure there are others who have done this for the exact same situation and area on the car. My questions are...

Is it okay to pound in this area of the undercarriage? Does it compromise the structure of the car?

How much safe clearance should there be between a wheel/tire and an inner fenderwell?

What kind of hammer do I use?

Will I have to re-spray the wheel wells with undercoating?

After I do this, does it look okay or does it look like someone "pounded on the car with a hammer"? I know it is hard to see with the wheel/tire on, but I still want to know.

Any helpful hints?

Thanks!

On my friends stang we just cut out the parts of the wheel well with a cut wheel and we stuck some 335's on a 10.5 inch wide wheel under there. Spray it with primer and some rust inhibitive paint that's all we did anyways :confused:

Originally posted by AW/whiteZ-28
On my friends stang we just cut out the parts of the wheel well with a cut wheel

Ahh...no...I think I will pass on cutting parts of my car off. Thanks! :):)

I pounded mine in as well. I just used a big hammer... like a hand held sledge hammer and went to town :D

The coating did "flake" away in this area from where I was hitting it with the hammer. They sell the undercoating stuff in a can and you can respray this area if you'd like.

Originally posted by Brent94Z
I pounded mine in as well. I just used a big hammer... like a hand held sledge hammer and went to town :D

The coating did "flake" away in this area from where I was hitting it with the hammer. They sell the undercoating stuff in a can and you can respray this area if you'd like.

How did it look after it was all done? Did it look like it was "hammered" or did it look pretty smooth and unnoticeable?

I don't want to do this and have it all banged up looking regardless if it can be seen with the wheel on or not. A good friend will help me if I decide to do this. He said we would use a deadblow hammer. The spot that I have to hammer seems highly reinforced, so I may decide not to do this.

I hate this crap. Not even 2,00 miles on my car and already I am looking to bang it up.:no:

It'll all be worth it Jay, after you get those sweeties on there.;)
I wouldn't worry to much about being able to see any difference, you'll be the only one who will ever notice, and barely at that.......
Happy pounding.:)

Originally posted by Pandamonkey
you'll be the only one who will ever notice, and barely at that.......


THAT'S the PROBLEM!! I am weird like that!:irk: :blah: :irk: :blah:

This may seem odd, but what about getting the right rims for your application so you won't have to massage any body panels?

Since you didn't mention so, are you running bigger than 315mm?

How accurate are you with a hammer is basically what it boils down to. You can pound in the spot until you have the clearance and then flatten the area around it to blend it a little so the difference isn't drastic. If you blend it nicely and spray it with the undercoating you'll never notice. It's like any other fabricated mod, just take your time and be patient, it'll come out alright.

What size rims are you putting on? Are you using the factory 18"/17" combo or all 18's or all 17's? I just put the 17" Z06 rims on my car and love it. It didn't take any modifications, but mine are only 17x9.5's. If you want a wider tire, you're gonna have to go the route of slightly modifiying the wheel well from what I understand. Good luck with your decision and post pics afterwards! :D

These are GM Z06 wheels, 17 x 9 in the front, 18 x 10.5 in the rear. I have been waiting to put them on since last October.

I am also concerned with structural integrity if I do the hammering.

If the car wasn't so new, I suppose I wouldn't care as much...

I put Y2K 17's/18's on my 94Z and dropped it 2in.
Mine "rubbed" a bit exactly where you said (9:30-10:00) all I did was to take my time and slowly hammer that area evenly (not hard) I then resprayed some undercoating on it. Not even myself can notice it and I got NO more "rubbing" even under hard cornering. As a precaution make sure your rear seatback is in the upright and latched position (you don't want anything moving out of position). Remember to take your time and that you really don't need to hit it too hard at all. Bang aaway!! :metal:

Well, I used a huge hammer and whacked the crap out of mine. I tried a smaller hammer but was making zero progress. On mine the coating in the wheel well kinda flaked off where I was hitting it. With the right style hammer you whould be able to get an "even" look. If you'll be able to get an even look when after spraying the coating on is another story? I never bothered to re-spray mine so can't tell you how well the stuff works :D

The structural integrity shouldn't be affected that much at all, if any. I understand that our cars out unibodies, and that pretty much everything serves some structural function, but the inner fenders/wheel wells main purpose (as you know) is just to keep stuff from flying up into the rest of the car. They aren't really "structurally supported" as in haveing any bars etc. bracing them, or coming from them, so you can't hurt that. GM beat them as they need to to fit them to the car (indentions for the rear Bose, etc.) so I would suppose you aren't really comprimising much structural stability whatsoever - from a theoretical perspective.

A deadblow hammer would be my "tool" of choice if I were going to do it. They provide enough force to do what you want, are a very managable size, and they don't hurt your hands.

I have used the spray on undercoating before - and guess what, so does GM dealers. In fact, I was helping my buddy work on his car at their shop (local Chevy dealer's body shop) and they had like three or four cans of Keystone's undercoating laying around - that's what they use on their wrecks. So you are probably pretty safe with that - plus the Wurth that I used lasts very well, and looks just as good as stock - or better, since you take time to not let it run, etc.

With a little bit of time and patience, you could hammer it out pretty smoothly. Like Brent done - you will probably just have to flail them to get them beat out some, but once you have them where you want them, you could spend the time to beat the lines in a little better.

Good Luck- hopefully that inspired you in some area.

You may have a problem with your ABS as a result of using two different wheel sizes. If the overall diameter of the tires, front to back, is off by much you can cause the ABS to think that a tire is slipping. It's not guarranteed that it's going to cause problems for you, but it's something to be aware of.

Originally posted by JDHarris
You may have a problem with your ABS as a result of using two different wheel sizes. If the overall diameter of the tires, front to back, is off by much you can cause the ABS to think that a tire is slipping. It's not guarranteed that it's going to cause problems for you, but it's something to be aware of.

The difference in diameter doesn't matter for the ABS computer. What the ABS computer looks at is a "change while moving" so to speak. When you start from a stop with different sized tires, the difference is constant. My buddy has 33" tall tires (tubbed) on the back of his 96SS with skinnies up front (which I believe are slightly smaller in diameter than the stockers) and he has a fully functional ABS system with no ABS lights.

Originally posted by Brent94Z
My buddy has 33" tall tires on his SSWow - so you know this (http://ist-socrates.berkeley.edu/~groch/Images/Cars/camaro.s_small.jpg) guy? :D

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!

Okay, so I stand corrected. I was going off of something I'd read here previously. Sorry for the misinformation.

Originally posted by JDHarris
Okay, so I stand corrected. I was going off of something I'd read here previously. Sorry for the misinformation.

No problem at all! That is a common misconception because I hear it often. Just wanted to reply letting people know that different sized tire diameters could be done! :D

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!

Originally posted by White Z 4 Show
I might have read it wrong but you are trying to roll the fenders, right?

Nope, we are talking about the INNER fenderwell...the vertical "wall" of sheet metal with undercoating on it that separates the wheel/tire from the rear hatch cargo area.

Thanks for the info anyway! :):) Hopefully it doesn't have to come in handy in the future! ;);)

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

Get wheel adapters.

Originally posted by KillerTA
Get wheel adapters.

What kind and from where?

have you asked santa? hope you was a good boy jason! hahaha

Originally posted by White Z 4 Show
have you asked santa? hope you was a good boy jason! hahaha

Crack head.

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 (http://cjcfo.fbody.com/members/injuneerzz@aol.com/PhotosA/Drivhamr.jpg)

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 (http://cjcfo.fbody.com/members/injuneerzz@aol.com/PhotosA/FendMas2.jpg)

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 (http://cjcfo.fbody.com/members/injuneerzz@aol.com/PhotosC/TirClr2L.jpg)

Clearance - passenger side from rear (http://cjcfo.fbody.com/members/injuneerzz@aol.com/PhotosC/TirClr1R.jpg)

Clearance - looking straight up from floor into wheel well (http://cjcfo.fbody.com/members/injuneerzz@aol.com/PhotosC/TirClr5R.jpg)

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 (http://cjcfo.fbody.com/members/injuneerzz@aol.com/PhotosC/Rr34Dr02.jpg)

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 anal, 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.

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 :D

-Dustin-

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.

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.

Just curious, Steve...have you raced with adapters? Ever had any problems?

I've autocrossed (using 315 Kumho V710's and Hoosier S03's) and run track days with them with no problem. If I was going to have a problem, it would have surfaced by now. I would probably think twice if I was running a 1/2" or larger but a 1/4" just isn't an issue.

I've autocrossed (using 315 Kumho V710's and Hoosier S03's) and run track days with them with no problem. If I was going to have a problem, it would have surfaced by now. I would probably think twice if I was running a 1/2" or larger but a 1/4" just isn't an issue.

You also had the longer studs, correct?

Steve, you are running 17x11" on the front??? Did you have to do any mods to the front to fit 11" wide rims other then a 1/4" spacer??

My front 17x11's are 36mm offset so I didn't have to do anything.

If you use a 50mm offset, you either need a spacer (1/4") or grind the little bump of the upper spindle arm.