larrywalk

Sorry, '75, but there's no way the side yoke moving inward will make the top of the tire move outward.

Scottd

Paul...your tires look as if they are just on the edge of those fenders, like your sidewalls actually stick out a little further. If thats the case, then my rear spring is surely wrecked. What are you running for a spring/shocks?

'75

I never said it would, re-read my post!!!!!!
I said that if the strut rod eccentric had to be adjusted that far to get 0 camber, there must be some side yoke wear, no mention of the tire leaning out. 0 camber is straight up and down.

Paul L

You are seeing the offset of those Centerline wheels. It is not your spring.

But FWIW, the spring is VBP #330 with KYB computer-designed shocks by VBP shocks match.

http://www.vbandp.com/C2-C3-Corvette...-set-of-4.html





I am beginning to wonder if Mike W. is on to something. You may have the wrong half-shafts. But I am going to stop at that. I cannot get further than my limited technical knowledge allows me. Others here have much more expertise.

Mike Ward

OK, turns out that half shafts are a red herring. I looked my notes, turns out the later models are shorter, not longer. Yours should be 13 7/8", '80-'82 are 13 12". Sorry.

The other hardware mentioned in your second paragraph are also red herrings. None of those affect wheel to wheel width.

Being that most C2/C3 bodies are not centred on their frames (no, there's nothing you can do about it), you might have an extreme example. That, coupled with the extra width of the tires might just be too much.

Paul L

Yes Mike,

I dearly would like to help this person but nothing more comes to mind. As I said previously it is not the tires. With a good suspension stance the 235-60Rs actually ride too low. That is why I moving over to 225-70Rs for 2013 (another thread here). I am lost on this one....

Scottd

I also forgot to mention that the body is not original to the car. Its a 82 body on a 72 frame. (But I STILL cant find any differences from side to side... I wanted to rule out all mechanical possibilities before I even considered this option. Im thinking that a bunch of 'tolerance stacking' combined with the bigger tires are the culprit. I think my best cure at this stage is a good stiff spring, max ride height and stiff rubber overtravel bumpers...?? I dont mind the 'butt in the air' stance, I kind of think it lends itself towards muscle cars. Whats the best way to gain and extra 1/3 clearance on the rear end? Is there any kind of lift kit?

Im thinking a new spring...but maybe going back to the stock tires....ARGHHH,, these tires have less than 50 miles on them....but stock calls for 205/75's, and Im running 235/60's....stock tires would not only give me more fender clearance but higher ride height. Question is, how much?

EDIT: 235's are 6 high by 9.25 wide. 205's are 6 high by 8 wide. HUGE difference. I need new tires. Anybody want to buy some brand new Firestone 235's?

noonie

235/60s are not grossly oversized. They are a little wider but much shorter than oem leaving far too much fender gap.
Below is a pic of a 75 and a 77, both have much bigger BFG255/60s and NO fender scrubbing ever, even both sides.

You're car has had some adjustments over it's life. It already has a replacement spring.
Sounds like the body wasn't centered at the rear when swapped. Have seen quite a few of these after body off restos.
Proper way is to fix that and not with tires, springs etc.
Get it up on a "drive on" hoist at "ride height" sometime and do a lot of measuring.
Skinny tires will help, but it's not the root of the problem.

An idea of what they should look like. Both 255/60 rear, white car has 545/60 front. All on alum factory wheels.

JimT

Check your rims to see if they all match. I've seen what was supposed to be a matched set of rims - they looked the same - but one was from a different manufacturer and the offset was a little different from the rest. Just looking at the wheels you couldn't see the differrence.
Has the car been wrecked? Someone may have done repairs and didn't align the body correctly.
Good luck,

leadfoot4

NO, you don't need new tires!!!

You have an issue of some sort, and simply changing tires is not going to fix the problem. I get involved with these C-3 discussion once in a while, because my wife owned 2 of them over the years, the last one being a '79 that she kept for 18 years. I did a LOT of work on that car, and have addressed a number of issues.

One thing I did with the '79, was to replace the body mount cushions. That was somewhat of a big job, and a big part of it was getting the body sitting straight and evenly sitting on the frame. It took a lot of measuring, pushing and shoving, to get the body aligned properly.

Since you've mentioned you own a newer body on an older frame, I think you should back-track a little, and start taking measurements of the body panels to the frame, both sides, from front to rear. It could be as simple as loosening all the body bolts and shifting the body around a little on the frame.

Keep in mind, you're having clearance issues with a 235/60 tire...a tire that's actually two sizes smaller than the tires that GM offered as an option on these cars.....

Garys 68

So the car was wrecked? Not many other reasons to swap a fiberglss rear. If everything is tight, is your frame strait?

Scottd

All the measurements Ive taken look good, but then again Im rolling around on the floor in a garage on my back with nothing more than a measuring tape. Whats the easiest way to measure a frame?

leadfoot4

If you're like many of us who live in the "snow belt" you've probably got the car off the road for the winter. You might want to wait until spring, and take it to a reputable frame/collision shop, and have them get it up on a frame machine, where they can accurately measure things for you.

I understand the agony of rolling around on a cold garage floor, trying to do stuff. If you don't want to wait until spring, buy yourself a set of ramps, and roll the car up on them. That will at least get you 3-4" off the ground. While it doesn't sound like much, 3-4" buys you a lot of "wiggle room". Also, try to get your hands on a shop manual. It will give you the points used to make the necessary diagonal measurements on the frame.

Scottd

I see you are from Webster...I guess you know my pain. Funny thing is I bought this car just outside of Webster!
I usually keep the car on rolling dollies during the winter, that gives me some room and lest me scoot the car side to side. Those dollies are amazing. My only apprehension of taking it to a shop is 1) there are only 2 places here in Syracuse I trust to know anything about older Corvettes and 2) The car has been so bubba'd that Im afraid they wont work on it. Besides, Im afraid to even drive it now. Im really convinced the body was put back on a tad crooked and the oversized tires are just too much. Nothing else makes sense.

leadfoot4

Scott, you're obsessing on the tires. Again, they're NOT your problem, as they're smaller in OD than either of the "correct" sizes for the car, so in fact, they're helping your clearance problem.

If the car is on dollies, that's giving you work room under the car, as well as keeping the suspension loaded, which is what is needed when working on the body, and/or measuring stuff.

Start by measuring the distance from the frame to the body along the rocker panelr, then move to the rear of the car, right behind the rear tires. The measurements should be the same on both sides. You mention that the body is on a different frame, so the body bolts hopefully arent rusted up badly. If you take some measurements, and they're off, side to side, you can try to loosen them up, and shuffle the body around.

There are, IIRC, two bolts in the rear (one on each side) one on each side behind the cover panels in the rear wheelwells (in front of the tires), one on each side at the base of the firewall, and one on each side at the radiator bulkhead.

Scottd

I can just loosen up the rear bolts and move the body over by 3/4 of an inch?????? Just like that? This Im going to have to see. (The ones in the wheel wells are actually missing.....)

leadfoot4

Not just the rear bolts, you'll have to get all of them loose...

Faster Rat

Scott
When I changed my rear shocks, I let the suspension drop, which only managed to flip my rear sway bar links over center on both sides. When I sat the car down, the rear end was sitting high and the tires were way out on the top. The half shafts did not like that either when I rolled it out of the garage. Can't tell from your pictures, but something to check. If you don't have a rear sway bar...just forget I mentioned this.
FR

Bob Heine

The 72 body mounts are different from the 82 body mounts. The 72 uses solid aluminum washers and steel shims while the 82 uses two-piece rubber mounts (and I assume steel shims). In this photo the mount on the left is the 72 mount and the one on the right is the 82. I'm not sure but I think the rubber mounts help locate the body better (quieter for sure).


There are four mounts on each side of the body.

Mount 1 is at the bottom of the firewall and difficult to see on your car. Here's a photo of its location on my 72 with the side grille removed (your 82 body doesn't have that large opening). Don't be confused by the gap -- I'm using an all-thread rod to lift the body and that aluminum washer is the 72 mount.


Mount 2 is inside the door frame behind the kick panel. The bolt has been removed but you can see the hole.


Mount 3 is at the front of the rear wheelwell behind an inspection cover. Remove the 4 screws and the cover and you can see the mount. Again, the bolt is missing from the picture but you can see the hole.


Mount 4 is behind the rear tire at the back of the wheelwell. Sorry about the rod but you get the idea.


In addition to those eight body mounts, the radiator mounting frame locates the front fenders and it might help to loosen those as well. Because you have a 72 frame with an 82 body, the crossmember might be different but there should only be two bolts holding the radiator frame in place on the frame. A bunch more bolts hold the inner fenders to the radiator frame but those shouldn't need to be touched.

Sunstroked

Body not aligned correctly would be my best guess. I just lowered the body back onto my frame this week. A little nudge is all it takes to move them with the body bolts loosened. I talked with a long time corvette restorer, it may take multiple attempts at shimming to get the perfect alignment of gaps, and every time squaring the body up is critical.