Team Camaro Tech banner

New Wheels, New Issues...?

6K views 37 replies 10 participants last post by  CamaroMan469 
#1 · (Edited)
I finally got around to replacing all of my suspension (front and back). I went with the following:

-Hotchkis 2" lowering coil springs
-Hotchkis 1.5" lowering leafs
-Hellwig front and rear sway bars
-Varishock QS1s front and rear
-SC&C Stage 2 Plus
-All new Moog steering components (pitman arm, idler arm, etc.)

Late last fall I had purchased some 18" Torque Thrust 2s (18x8 w/4.75" bs for the front, and 18x9.5 w/5.5" bs for the rear). I had a local shop measure the front and rear (passenger side only :mad:, my mistake...) to make sure they would both fit. Once they gave me the "thumbs up" I placed the order.

Over the past 2 weekends, I replaced all of the suspension and went to put the new rims and tires on (I was soooo excited)...but then the worst possible thing happened...the rears didn't fit. Here are some pictures:

Passenger Side:


Driver Side:


As you can see, I have some problems.

It's hard to tell from the pictures, but on the passenger side, the outside of the tire is dead even with the edge of the fender lip. On the drivers side, the outside of the tire is even with the trim screws (about halfway into the fender lip).

The quarter panels have both been replaced by the car's previous owner, and they did a terrible job, especially on the driver's side. The tires are 275s...

What are my options? I don't have the money right now to order new rims, so I would prefer to make these work. I am open to trimming/rolling the fender lips, but I don't think that would make the driver's side work...

Do you guys think that a 255 series tire would help me out?

I am open to all suggestions. I know it is my fault that I didn't have the shop measure both sides prior to ordering them, so please take it easy on me.

I really appreciate all of your help! I need some smart ideas on this one...

Thanks,

James
 
See less See more
2
#2 ·
if it's the installation of the quarters you don't have many options except for some smaller tires or wheels with some more backspacing to bring them in some.

Is your rear centered? Doesn't look like it would help much, but if the whole thing went over to the passenger side 1/4" or so, would it make it any better? There's definitely some adjustment in the front spring cups.
 
#3 ·
Thanks for the reply!

The rear end is a brand new DTS 12-bolt, and no it is not perfectly centered. It is slightly off center toward the driver's side. When I had the alignment done, the tech said that the rear was tracking perfectly straight though. I also did some cross measurements, and the body is square on the chassis (+/- 1/4").

I don't think that an extra 1/4" toward the passenger side would help too much. I think it would start creating issues over there.

I'm trying to decide whether a 255 tire would help or not...I know a 255 would be around 0.4" skinnier, so I might gain around 0.2" on each side. That may help a bit, but I don't know if the combination of that and a fender trim/roll would be enough...
 
#4 ·
I'm not a wheel expert or engineer, but it may also be possible to take the driver side wheel to a machine shop and have them put it on the lathe and machine the mounting pad down some to add some backspacing.

I've got no idea what that would do to the strength of the wheel, but if it's thick enough, I don't see what 1/8 or 1/4" would do. Combine that with rolling the rear quarters and maybe a bit smaller wheel and you'd probably have more then enough space.
 
#11 ·
Since the rear end is positioned on the leaf springs you would have to determine why the rear is not centered under the car. It's either the springs are not positioned correctly, or the perches on the axle tubes are not mounted in the right place. There is also a chance the quarters are not mounted exactly right and the rear is centered and square to the frame rails. There is no adjustability built in, everything has to be square when you bolt it all into place.

Any time you try to push the envelope with wheels and tires the car has to be perfect on top of and around them.

Forgetting the math and just looking at the pictures I don't think splitting the difference and centering the rear end will solve any problems with those tires and wheels.

My suggestion is start making sure you got what you paid for spec wise. Measure the wheels, width and backspacing... Measure the rear housing, axle flange to axle flange and on center from perch to perch. Also measure the wheel houses, do you have the same room from fender lip to frame rail on each side?

Once you know what you are working with then you can come up with an action plan... I think your car is a '68 so with the round wheel wells you might be able to work the ride height and suspension so the fender never drops down onto the tire. You might be able to swap to a 275/35/18 it's an inch shorter than the 275/40/18 and would give you 1/2" extra clearance below the fender lip. 255/35/18 is about 1 1/2" shorter and about 1" narrower in section width...

I have to ask, what does the inside clearance look like? If you have room and the wheels have thick pads you might be able to have the pads machined a little for extra back spacing.
 
#12 ·
Forgetting the math and just looking at the pictures I don't think splitting the difference and centering the rear end will solve any problems with those tires and wheels.
My suggestion was to split the difference and go with a narrower tire. That should make a difference. I would check the backspacing just to make sure you got the right wheels.


However, as Dennis said, the rear really isn't adjustable per se. You can check the front leaf spring pockets to make sure they are positioned correctly. If the bolts weren't tight, one or both could have twisted/shifted. It wouldn't take much to move 1/4" to one side.

Another consideration is to make sure all suspension parts were torqued down with the full weight on the wheels. If anything was tightened while the suspension was not loaded, it could sit uneven causing the car to shift to one side.

Since everything is new, the shackles shouldn't be bent and the leafs shouldn't be twisted (either of those could cause a shifted rear). One last thing is to check to make sure the rear leaf centering pin is seated in hole in the spring perch. That would certainly cause the rear to shift to one side.
 
#19 ·
My gut tells me wheel manufacturers don't have different centers made for every possible backspacing. They probably make them in for instance a 4" backspacing and then machine what's not needed off, but again, I'm far from an expert.
 
#20 ·
If you buy high end wheels they often will tell you how thick the pad is. Most wheels that are production made and sitting in retailers inventory have very generic back spacing or offsets that will fit on the most possible combinations and won't have much or any extra material in the pad. Wheel design can leave the pad with extra material on it, a lot depends on how the wheel is designed around the lug holes.

A good wheel shop that has the equipment and does wheel repairs will know the safe limits in pad thickness and will not remove more than what is safe.
 
#22 ·
I did try switching rims/tires from one side to the other with no success. I am going to try a 255/40/18 this Friday to see if that helps at all. I'm hoping that the extra ~0.4" and a fender lip roll/trim will do the job. If not, you might be seeing these rims/tires go up for sale soon...

Do you guys think that a 255/40/18 will look bad on a 9.5" rim? Do you guys have any pictures of what it might look like?
 
#24 ·
Measure your rear end flange to flange or back of axle to back of axle and post up the measurement since it's a new build. I'll check mine to compare.

Maybe easier to measure from back side of tire to inner fender, or back of axle flange to leaf perch. Just to get some measurements to compare to others.

That width tire and rim tucks on my '69 with rear discs.
 
#28 ·
255's have a section width of 10.2" and don't look stretched on 9.5" wheels, I've been running them for years on my '69.
Those don't look too bad at all Dennis. I was thinking they'd have a little more of an "import" look to them. What size are your fronts, and do you have a good shot of your front to rear comparison?

My thoughts were that a 245/40/18 on an 18x8 would not have the same profile as a 255/40/18 on an 18x9.5 since the tires are only .4" (10mm) wider, but the wheels are 1.5" wider.
 
#29 ·
My wheels are 17" but before anyone says we are not talking apples to apples with 18" wheels, 255's in both sizes have the same section width within about 1/10" and the 18" wheels typically have just a bit more tread width so the 255 on a 18" wheel will look wider than on a 17" wheel. Even with the difference in 40 and 45 series tires you won't see the 255 sidewall roll into the tread.

Now as far as sidewall height and looking okay you don't need that perfect combination front and rear that gives you the exact same sidewall height. I started out wanting it (275/40 and 245/45 gives it both 17" and 18") but settled for a slight difference.



The fronts are 235/45 and the rear are 255/45 and there is .7" difference in height. That's a .35" different sidewall with the fronts being shorter. I don't think its noticeable at all...
 
#30 ·
The fronts are 235/45 and the rear are 255/45 and there is .7" difference in height. That's a .35" different sidewall with the fronts being shorter. I don't think its noticeable at all...
I actually like a little more sidewall on the rear tire than the front, so you won't get any criticism from me. I'm running a 245/40/18 and 275/40/18 combo. I originally thought about doing 275/35/18's in the rear, but decided against it.
 
#31 ·
Thank you all for your help and infinite wisdom.

I ended up doing tons of measurements of the wheels, frame rails, axle tubes, perches, wheel well, etc. I came to the conclusion that my rear was almost perfectly centered (about 1/8" to the passenger side).

I decided to trim the fender lip, but making sure to not trim to the spot/pinch welds. I ended up getting around 1/4" of space on both sides. I think I'll be able to keep my 275/40/18s after all. Here are some pics:





 
#37 ·
Thanks for the compliment!

Unfortunately, I didn't take any pictures during the trimming process , but I do have a finished product picture. I'll post that below.

This was my process:
1. Remove trim
2. Measure from pinch/spot weld to inside of fender lip
3. Make marks at a reasonable distance away from the weld
4. Make a "comfort guide line" with a scribe along that line
5. Use painters tape to help protect the finished exterior paint
6. Use electric sheet metal shears to trim along that line (make sure to angle the shears so the handle is away from the outside finished paint)
7. Test fit the rims and use a straight edge to check clearances from about "10 to 2"
8. Once you are happy with the amount of trimming, reattach the fender trim
9. Use a fine tip marker to go along the top edge of the newly cut fender lip, marking the cut line for the trim piece
10. Take the trim back off and cut the trim piece to fit the fender
11. Reinstall the trim piece and make sure it follows your cut line (I had to drill new holes closer to the outer fender for 3 of the trim screws)
12. Next, I used a die grinder with a soft stone to soften the edges and remove the sharp pieces (I made sure to go very slowly and take breaks so that the metal didn't heat up too much and wreck the paint)
13. Have a beer (or two...or five)
14. Go back and prime and paint the bare metal that you just created. You'll thank yourself later.

The entire process took me about an hour per side (not including the priming/painting). It wasn't bad at all. Keep in mind that I'm a novice at this kind of stuff. I had never used sheet metal shears in my life, but man was it easy.

Here is a picture of the passenger side finished product:



It may not be perfect, but I am overall happy with the result. Keep in mind that I only trimmed the area at the top that the tire has a chance to touch. You'd only notice it if you crawled under the car and looked for it.
 
#38 ·
Thanks!

I also wanted to add: I took a 2 hour round trip yesterday on Michigan roads (terrible potholes, etc) with speeds ranging from a creep to 80 MPH and I have no rubbing or scratches of any kind on the tires. I think my Hellwig rear sway bar may be helping a bit, but it's good news nonetheless.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top