C3 Frame Check

[Bill B.]

Have a clean 72 convertible frame with suspension on and no motor or trans. Where in the Waco/Austin Texas area can I take it to have it checked.

[William C.]

Re: C3 Frame Check

I'm not sure what you mean "checked" but if you mean for straightness, any good body dhop with a frame bench should be able to do the job.

[Bill B.]

Re: C3 Frame Check

Thanks Bill. Guess it was probably a stupid question but I had my 90 fixed several years ago at a local body shop (suppose to be the best in Temple, Texas) and it was not a good experience. It had frame damage and I did not trust the work. Just thought that someone in this area might know a shop that performs every time and has the reputation to go with it! Oh, I am wanting to make sure it is straight since she rode a little canted before the restoration--all the diagonals checked okay for me? I just want to make sure of things after all this effort.

[Mike Cobine]

Re: C3 Frame Check

Before you take the car in, have a copy of the frame dimensions from the serive manual. Often they do not have one that old or they have a generic one for all Corvettes 1963-1967, 1968-1982, etc.

Have the body mounts loose. If they twist the frame any to straighten, you don't want them twisting the fiberglass, too. Tell them the mounts are loose, in case they decide to use body points to measure.

[Mike Cobine]

Re: C3 Frame Check - have a motor and trans in it

Often if the frame is bent from an accident, the motor mounts can be off slightly once all is back straight. You don't need a whole engine, just a block, bellhousing, and transmission case so that all three mounting points are connected.

[Bill B.]

Re: C3 Frame Check - have a motor and trans in it

Mike, I have the frame specs from the manual to provide them. I was told by one shop that I just needed the wheels on (the body is off). I am currently completing the chassis restoration and should be ready for the body sometime this summer. I don't mind waiting in this process but I did not want to go to far if I shouldn't. Can things be done with all the chassis together provided the body mount locations stay within specs? Or, guess I should go ahead and complete things as you say and then just make sure body is loose at the mounts when I get that far. I personally think that the carrier is slightly moved (1/2 inch) as the drivetrain looks a little crooked from the rear to me. It seems to me that trying to correct this at the trailing arm shims would be too much. I really had not thought of the motor mounts and that could be the issue too! I am sure it is something obscure and would not take a tremendous "tweak"--I hope!

[Dick W.]

Re: C3 Frame Check - have a motor and trans in it

I repaired a C-4 that took a hard hit to the front spindle. Had the frame shop massage the frame back to specs. Two or three years later the customer destroyed the engine, lack of oil. Luckily he took it to another shop. They pulled the engine and tried to install another engine. Didn't take but two days to accomplish this task. Seems the engine mounts on the frame were off almost one inch

[Chuck R.]

Re: Ya'll dodged a bullet on thata one huh? *NM*

[Bill B.]

Re: C3 Frame Check - have a motor and trans in it

Thanks Mike and Dick. I think at this point I am going to complete the chassis less exhaust and tank. Then, I am going to see what a local shop gets with everything together except the body on her. Dependent upon their finding(s) I,ll take a next step. Figure that the worst that could possibly happen is that I might want to have the body on before they actually do any straightening if needed. Just Dependends? I feel comfortable after hearing from you guys. Thanks again.

[Terry M.]

Re: C3 Frame Check - have a motor and trans in it

Bill,
Just to be real clear -- I think moving the frame around (as in straightening it, not transporting it) without the body in place is a real bad idea. I know of one individual who undertook the restoration of a Corvette that had body damage (building fell on it) while the body was off the frame. Getting the body to fit the frame again was a nightmare for several shops.
I would think that changing the relationship from the other direction would be just as bad.

[Bill B.]

Re: C3 Frame Check - have a motor and trans in it

I am with you on this subject Terry. I think I want it checked more for the piece-of-mind at this point rather than for repair. If all is okay then I have some other issue going on--just want to know. If they found something I think I would wait till I had the body on to actually start any kind of straightening. Although I have two cars in body off mode this is my first to actually be putting things back together. I just want to do things at the right time. I was really worried that I would complete the car and take in for checking and someone would say "you have to remove the body". The frame is in excellent condition for her age and I really don't think much is wrong except--you could see her tracking crooked from the rear. With my limited knowledge and experience I once thought that alignment might be really, really screwed up? My gut tells me that the carrier crossmember and rear kickup has been moved from some very minor impact. The car did have the original driver quarter panel repaired but the carrier movement (if wrong) is in the opposite direction. With all your help on the board I will get through it. Thanks.

[Dick W.]

Re: Ya'll dodged a bullet on thata one huh?

Ya said that right

[Mike Cobine]

I'm sure it wasnt' tracking as crooked

as the Ford E350 that pulled out in front of me tonight. His rear tires must have been 6 inches to the right of where the fronts were. And it looked like a new van.

[Mike Cobine]

The Good and the Bad Points

Good is that they can get to everything and can measure everthing easily. It is also easier to lay a level across the body mounts to be sure they are where they are supposed to be. You might have to reminded them to do that.

Depending on the shop, ease of doing it translates into less shop time and lower costs. However, you may want to add enough extra checks that it becomes more expensive. Still, you can do those extra checks easier. Like body mount positions, location of rear end and cross member, etc.

Good is there is no cracked fiberglass.

Good is they can grab anywhere on the frame to bend back evenly so there are not the tell-tale kinks.

The bad is that without the weight of the car, they won't align the suspension. On a '63 frame, the shop attempted to pull the frame down to "load" it but they couldn't get it to act right, so they passed on alignment. In my case, that didn't hurt, but easily could have if the suspension points had been bent in a different direction.

Bad is that the body mount locations could be missed if they do not check that separately.

Bad is that items like the seat belt tabs could be a bit too high and hit the body when it is reinstalled.

With no engine and transmission, the motor mounts are often not where they should be. But if possible, use a junk block so that no strain is on your original block.

Remember that the engine and transmission are offset to the right one inch.

[Bill B.]

Re: The Good and the Bad Points

Super Info Mike! I feel equipped enough to take the right action at this point. My problem is that I really didn't/don't know exactly how difficult it is to do some things with the body covering areas. Seemed that areas would be really easy to access without everything there as long as "major" twisting or pushing was not required. I sort of feel like the mid-rear kickup area needs some encouragement and that only the #4 mounts would be slightly affected--I know. I am very aware of problems related to putting body back on, however, I have never put one "back on" before. By the way, it didn't track like the E350 you saw. I have a really good eye for things like this and it was enough to just plain bug me! What a wonderful experience to see something that you have done which belongs in the garage and is clean enough to sleep with. Cannot get her out of my dreams--my wife just tolerates me at this point.