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The quarter panels have both been replaced by the car's previous owner, and they did a terrible job, especially on the driver's side.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

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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.
 

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Discussion Starter #3
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.
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...
 

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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.
 

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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...
I think your math is a little off. 20mm is almost .8", so you would pick up about .4" per side. If you combine that with centering the rear (moving it .25" towards the passenger side), then you will pick up roughly .65" on the drivers side and .15" on the passenger side. That should help quite a bit.

Take a straight edge and line it up with the outside of the tire. Put a temporary mark on your fender lip, then put another mark .65" in and see if that's enough clearance for you. You can do the same on the passenger side, with the second mark .15" in and see if it looks symmetrical.
 

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Discussion Starter #8
I think your math is a little off. 20mm is almost .8", so you would pick up about .4" per side. If you combine that with centering the rear (moving it .25" towards the passenger side), then you will pick up roughly .65" on the drivers side and .15" on the passenger side. That should help quite a bit.

Take a straight edge and line it up with the outside of the tire. Put a temporary mark on your fender lip, then put another mark .65" in and see if that's enough clearance for you. You can do the same on the passenger side, with the second mark .15" in and see if it looks symmetrical.
When I get the car back from the transmission shop I will try this. I'm not familiar with "centering" the rear end. What do you adjust to move it to the passenger side?

Also, what brand are those tires, and what's the section width? (275/??/18)
The tire is a Cooper RS3-S and the size is 275/40/18.

Thanks so much for your help! You have given me hope! :beers:
 

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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.
 

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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.
 

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Discussion Starter #13
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.
I will make sure to measure the backspacing on the wheels when I get the car back. I made sure that all of the suspension components were tightened while the car was on its wheels, a full load. The rear leaf centering pin was correctly placed inside of the lower mount hole as well.

I will double check everything and make sure that all of the new pieces are what I paid for too.

The different tire option may be the next thing to try...

I'll keep everyone posted.

If anyone else has some more ideas, let me know!!
 

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Discussion Starter #15
Here's a thought, if nothing else works. How much are two new tires going to cost? Can you just buy one new wheel for the drivers side with a little more back spacing and keep the 275's?
I bought the tires locally, and they have zero miles in them. Hopefully they'll just exchange then for me, maybe for a small restocking fee.

I could buy just one new rim for around $350, but I'm not sure if that's the best solution...
 

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I bought the tires locally, and they have zero miles in them. Hopefully they'll just exchange then for me, maybe for a small restocking fee.

I could buy just one new rim for around $350, but I'm not sure if that's the best solution...
Definitely see if you can get it centered first. But one thing to realize is that a lot of these cars came out of the factory not centered. Tolerances weren't exactly what they are today.

If you don't want to buy a new wheel, as suggested before, you could take one to a machine shop and see if there's enough meat on the hub to have a little taken off. Some shops probably wouldn't even touch it since it becomes a safety/liability issue, but it may be worth looking into, and may cost a lot less than buying a new wheel.
 

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Discussion Starter #17
Definitely see if you can get it centered first. But one thing to realize is that a lot of these cars came out of the factory not centered. Tolerances weren't exactly what they are today.

If you don't want to buy a new wheel, as suggested before, you could take one to a machine shop and see if there's enough meat on the hub to have a little taken off. Some shops probably wouldn't even touch it since it becomes a safety/liability issue, but it may be worth looking into, and may cost a lot less than buying a new wheel.
Would that significantly compromise it's structural integrity? If it will become a safety issue, I don't know if I'll feel comfortable doing that.
 

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Would that significantly compromise it's structural integrity? If it will become a safety issue, I don't know if I'll feel comfortable doing that.
It would be up to the machine shop to decide that. If the hub is thick enough, it might be fine. If not, then they probably wouldn't even want to touch it.
 

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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.
 

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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.
 
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