Rear Spring Question.

[minendrews68]

While building my '68 Camaro, I ordered new rear springs (5 leaf spring). I ordered them from Classic Industries. My question is, are there different spring rates for these? I'm asking because when I go over something like a speed bump or a rise going into a parking lot the tires will rub the fender causing the metal to pull from the lip a little. Seems like they aren't stiff enough, but I don't know. Any ideas? I need to roll the fender lips, but it draws me up since it's already painted.

[dhutton]

Are they lowering springs? Hotchkis and DSE drop springs have a high spring rate but they ride like crap imho. If you are happy with the ride I would trim the lips (as opposed to rolling them) rather than sacrifice ride quality.

What is your wheel size and backspacing?

Don

[minendrews68]

Thanks Don, The wheel size is 15" x 7" stock rally wheels. I do not know the back spacing. I'm wanting to get wider wheels for the rear but I'm thinking I'm already rubbing as it is... As far as I know they are not lowering springs. They were just factory replacement springs.

[dhutton]

That is odd for a 7” wheel. Here are the backspacings versus width to center the wheel in the wheel well for a first gen. Ignore the 17” diameter.

17x7 = 4.25"bs
17x8 = 4.75"bs
17x8.5 = 5" bs
17x9 = 5.25"bs
17x9.5 = 5.5" bs

What size tire are you running?

Don

[minendrews68]

225/60 r15 BFG radial gt on the front, 255/60 r15 BFG radial gt on the rear. I've always wondered if the rear end housing wasn't part of my problem. I bought it from a friend of mine that had it under a 1st gen Camaro race car. Even though it was physically under the Camaro I believe it was out of a Chevelle. It had the "rings" for a lack of better description on the top of the housing. Camaro's did not.

[dhutton]

I think that rear end might be two inches wider than a stock Camaro rear end.

That is a pretty wide tire for a seven inch wheel. It is quite tall too. Both are aggravating the issue imho.

Don

[JustJohn]

Have a look here. These guys are pretty good about having OE factory drawings to work from and list 3 different rear springs for a coupe:
https://www.eatondetroitspring.com/

[dhutton]

I would not sacrifice ride quality and try to fix this with stiffer springs.

Don

[minendrews68]

maybe, first off I need to look at the correct rear housing. Then move on from there.

[dhutton]

maybe, first off I need to look at the correct rear housing. Then move on from there.

At least measure the housing. Should be around 60” wheel mount spacing for a first gen. Later Chevelles were 62”.

Post up some pics of your wheels in the opening.

Don

[BMR Sales]

I agree your Housing may be too wide - what Shocks are you running?

[minendrews68]

Don, attached is the pic you requested. A little larger than I expected but here it is. You can see, about the two o'clock position where the tire caught the lip and pulled it down a little.

172363

TC, The shocks are stock Monroe

[dhutton]

Pretty sure your rear end is too wide. You can change it out or get wheels with more backspacing but if you have less lip in the rear than front it looks bad.

Try to find an 8.5” 10 bolt rear. They are pretty decent and less money than a 12 bolt.

Don

[minendrews68]

I think I'd rather find a 12 bolt housing because I already have the posi, new gears, etc for the 12 bolt. Thanks for you guys help on this by the way....
I am also toying with the idea of (like Don mentioned earlier) maybe getting a wider rally wheel for the rear with more back space. This would be cheaper in the long run..

[dhutton]

I think I'd rather find a 12 bolt housing because I already have the posi, new gears, etc for the 12 bolt. Thanks for you guys help on this by the way....
I am also toying with the idea of (like Don mentioned earlier) maybe getting a wider rally wheel for the rear with more back space. This would be cheaper in the long run..
Going wider may make it worse. What you need is less front space. But again, you will likely have more lip up front than out back and that won’t look right.

If you go wider add one inch to the backspacing numbers I posted above to account for the wider rear end.

don

[BBBluey]

Your diff is too wide, overlooking a spacer, or wheel offset is wrong. My friend has a stock 68 convertible camaro with 8in rally wheels and stuffs a 295/50r15 BFG in the rear.

For my 70 Nova I bought 5 leaf OER (145 rate) springs and mine are way too stiff and put my rear shocks (Bilstein) at full extension. Now contemplating between removing a leaf to see how it rides after or switch to a coilover suspension.

[minendrews68]

Your diff is too wide, overlooking a spacer, or wheel offset is wrong. My friend has a stock 68 convertible camaro with 8in rally wheels and stuffs a 295/50r15 BFG in the rear.

For my 70 Nova I bought 5 leaf OER (145 rate) springs and mine are way too stiff and put my rear shocks (Bilstein) at full extension. Now contemplating between removing a leaf to see how it rides after or switch to a coilover suspension.

Hey Don,
This is Carl Wilson. I looked at buying a new (or used) rear housing for my Camaro. Used ones are almost non existent and new Moser housing with tax and shipping is $1554. There used to be a guy here in Jonesboro that narrowed rear ends but moved about a hour away. Just called him and he’s still in the business. We talked and he told me he charges $150. He’s been doing this for over 25 years and has all the jigs.
He mentioned using Ford ends and doing away with the “C” clips.
He’s going to call me back tomorrow and give me a price doing the job complete or with me taking him just the housing. Complete would be with Moser axles.
What do you think?
Thanks,
Carl

[dhutton]

Hey Don,
This is Carl Wilson. I looked at buying a new (or used) rear housing for my Camaro. Used ones are almost non existent and new Moser housing with tax and shipping is $1554. There used to be a guy here in Jonesboro that narrowed rear ends but moved about a hour away. Just called him and he’s still in the business. We talked and he told me he charges $150. He’s been doing this for over 25 years and has all the jigs.
He mentioned using Ford ends and doing away with the “C” clips.
He’s going to call me back tomorrow and give me a price doing the job complete or with me taking him just the housing. Complete would be with Moser axles.
What do you think?
Thanks,
Carl

Hi Carl. That sounds like a good option. Your choice of ends might depend on your plans for brakes. For the kind of driving you do C clips are probably ok.

Don

[minendrews68]

Hi Carl. That sounds like a good option. Your choice of ends might depend on your plans for brakes. For the kind of driving you do C clips are probably ok.

Don

Ok, this guy has always been pretty highly regarded as being good at this work. Oh, you need to clean out your pm box.
Thanks for your help again...