Just put new T/A Radials, 255/60-15s on all four original 15x8 rally wheels on my '70 conv. Bolted them on as it was getting dark, and then when I pulled into the garage I heard the left front rub the forward section of the fender when turned to the right. Ouch, a little less paint in the wheel well and now a small crack at the bottom.

I checked the wheel clearances and there seems to be plenty of room on the right front tire, but the left front hits the front lower wheel well when steering to the right only.

I've only had her for a month, have put about 750 miles on her, and she has always driven perfectly straight down the road. The tires that were on it were 215/70-15s and didn't rub.

Where should I start with this? It bothers me that the left side rubs and the right side doesn't--makes me think something is tweaked and out of whack.

What should I check first? BEFORE I get smaller tires!

Thanks,
Rich

 

Congratulations on the new to you Corvette! I would do a visual check to see if anything looks bent or worn out. If everything in the front end is in good shape take it to an alignment shop. Besides, if you change tire size you need a alignment anyways. I have a 79 so not sure if there is any difference in the body than yours but years ago I had completed a front end rebuild. I did not place any of the shims back in at the upper control arms for the short drive to the alignment shop and the camber was so far off that when I turned the wheel the tire just slightly touched also. Good luck.

 

My 75 has same problem seems like it showed up after I rebuild the front end. I went with smaller tires 225 I think. I found a front end guy that really knows his stuff,and said he can do some tweaking when I bring it in for a alignment next time.Just gonna get my mileage out of these tires for now.The answer out there I just haven't brought it back in yet.Good Luck

 

Nothing obvious on any of the control arms, etc. The tire specs showed these were one-tenth of an inch larger in diameter than the ones that came off, but I guess they are a good inch and a half wider. Tire guy wanted me to put 265/60s on.

Since it drove straight before and the old tires were very evenly worn, no cupping or anything, Could the body be misaligned on the frame? Is that something I could determine and fix by myself?

 

The alignment can be way of and the car may still drive strait and handle well. I also 255 60 15 on 8 in wheels and my car is lowered. As stated before with the alignment off my tires rubbed, after having it aligned no more rubbing. It may be possible if the body mounts have warn out and that the body may have shifted, but the front of the body under the nose of the car is not mounted on rubber. Where on the body are the tires rubbing? Any photos?

 

make sure the wheels are AZ's. gm made many different styles of rally wheels with less offset that will cause tire rub.

 

i had same problem with my 75 after redoing front susp. would rub only when turned one direction. took it in for an alignment and no difference. also, i have extremely over-sized tires all around. my advice- get smaller tires and quit over thinking the problem.

 

Hi Rich,
The 215-70 that was on your car is the modern equivalent size of the F70 that was originally on your when new.
While the 255-60 tire is about the same height as the original, it's MUCH wider.
It will rub on some cars and not others. If nothing else, it might just depend on exactly how straight the body was set on the frame.
Just exactly where does the tire rub? When the std tire was changed to the 255-60 I believe the front fender lips were trimmed on the production line.
Regards,
Alan

 

Alan,

Is it possible to loosen body mounts and slightly adjust body position on frame?

Roger

 

Ok. I took a few photos. The right front tire is fine, no issues on that side at all. On the left front with the steering wheel about 1-1/3 turns to the right, the tire rubs on the lower front wheelwell here.....



With the steering wheel 1-1/2 turns left the left front tire also rubs the rear of the wheelwell as in this picture....

The right front tire has clearance all around, and looks like it will be ok with suspension travel, too. Looking along both sides of the car from the front, it's hard to tell, but I get the impression that both left side tires stick out farther than the right side tires.compare the two photos....


So, I'm thinking my options here are:

1. put the spare on the left front, bring the other wheel to the alignment shop and see what they can figure out

2. Trim away at the body,

3. Get smaller tires

4. Is the body out of alignment?

Any other ideas? I'm leaning towards #1 since I would like to have an alignment done anyway, and I think there is some play on the right front.

What do you think?

 

Oh, and yes the wheels are all AZs 15x8s. Thanks

 

Update! At the shop, I found out the cradle had been cracked and welded on bothsides. Left side sticks out a little more(<1/4"). but translate to about 3/4" at the end of tire! Getting some 215/70's to replace the fronts.

Mechanic said he has seen this a lot on C3s and there used to be a "kit" to fix this problem.

Anybody here of this?

Thanks, Rich

 

Hi Rich,
I'm glad you've been able to get to the bottom of this.
No, I've never heard of there being a "kit" to fix this.
Maybe urban or suburban "mechanic's legend"?
Regards,
Alan

 

why not go to 245/60 15 in the front to get your clearance?

 

I put 255 60's on the rear and 235 60's on the front to avoid clearance issues. However there is a bit more of a gap on the front than I would like

 

While it was up on the lift, the mechanic(Walt) and I were taking measurements, and comparing both sides. Then one of the other mechanics(Kenny) comes over and says, "I'll tell you what's wrong with it right now! It's a Shark body Corvette!" and I am like, hahaha, real funny!
Thinking he was just razzin' me. Then he went right to the cradle and showed me the welds and explained it. It needs a new idler arm, too.

As far as the kit, he said he has done two or three of these C3s with cracks and welded them up. He said it is pretty tough to get it exactly perfect with the engine, and front end and all in place, but it is close. The aft lower left end is off by about 1/8-3/16" and to compensate, the left assembly is pushed outboard just enough to cause a problem with wider tires. Kenny told me that the welds were good and looked solid. It drives perfectly straight and handles fine.

Somebody came to Kenny with this kit about 5 years ago. He said it came with a template and braces that he had to do a little cutting and drilling and bolted it all up. And then he followed it up with some welds.

So knowing that the 215/70s don't rub, And they are very close in profile size(215x70%=150.5 and 255x60#=153) only 2.5mm off, they should fill out the wheelwell and look pretty close in size fore and aft.

Thanks for the photo, Roco. How do you like those Coopers? I went with the BFGs--had a set on my first car--'67 Chevelle back in 1980!

I guess the question I have now, How common are these cracks? And how do they affect the value?

 

I suspect that you are talking about the brackets that are welded to the rear portion of the cross member that the lower control arm cross shafts bolt to. If this is so my 79 welds were cracked on both sides. In the Chevy power book it tells how to reinforce this. If you PM me your email address I can email you a PDF copy and photos of my frame where I repaired and reinforced this area.

 

That would be great Mac79vette. PM sent.