Is there any simple way to check a 66 frame to see if it is bent or sprung? Or is it best just to go to a shop?
Jim

measure from corner to corner. in an "x" pattern. the frame should not very by more then a half inch.

Without some knowledge of frame repair specs and conditions, it's almost impossible to get a reliable idea of whether the frame is bent and if so, how much and in what plane/dimension.

If you suspect your frame is out of spec and don't have the above knowledge, I'd highly recommend taking it to a shop that has a computerized measuring system to get a thorough diagnosis.

The "X" measurement mentioned by the previous poster is a common thing, but it only measures one plane/dimension of the frame and isn't reliable unless coupled with several other measurements and some frame knowledge to go with them.

The original frame dimensions are available from any of the suppliers we hear about on this site: NPD, OPG etc. I got them for my 67 when I was cnsiderig having the frame shop check it.

exactly. the x method is just a quick check that would answer quickly wether further investigation is needed. chances are if it is still square, it has not taken any good hits. it i have had frames that took a good side swiping and remained square. even after it cracked off the front lower control arm mount.

Realistically, you don't need the factory dimensions, or the computer. For that matter, the factory dimensions won't be in any computer data base anyway.

All you need is a bodyshop to check it out. They can measure it, along with visual inspection can tell you pretty well where you are.

I seem to remember a procedure was shown in my Fisher body service manual for '65. Maybe you can get a look at one of those.

My $0.02

Thanks guys, the problem I am trying to solve is the left rear rides about 1/2" higher them the right side. Front and rear ride heights are the same. the trim heights at the firewall and in front of the rear wheel are the same. the height of the body mount above the rear axel near the spring meets the underside of the body is about the same. The body mount behind the rear wheel on the left side is 1/2" higher then on the right side. And so is the left mount at the back near the rear bumper. Car looks great from the front, left and the right. But from the rear you can see it is not level. Didn't notice this when I bought the car last spring, the guys driveway must not have been level. There has been previous damage to the left rear as a full replacement rear quarter panel has been installed, think the frame was also bent; but not checked or repaired.
So, if the rear part of the frame on the left has been bent up, can it be pulled down? If so, what damage will be created when the body is pulled down when bolting up the body mounts? Or should one shim the body mount along the right side to gradually bring up the right rear to be level with the left rear?

Try to shim up with large washers inbetween the car and mountbushing. Losen up all your body mounts,jack the car up add a washer or two on either side to try to bring it level. You must use caution not to get outragious. You can crack your winshield or back window. Go slowly. Set the car down on your shimms (large washers), then check your door jams to see if they got to tight. You should correct the problem within a 1/8 inch.

Listen, measuring these points is not that easy. It is no big deal and easily done, but you have to be sure you are getting the right information.

First, put it on your nice flat garage floor, NOT a driveway or some something like. You need to measure how high the frame is off the floor first. If one area of the frame is not the same as another, so you find the right rear frame rail is lower to the floor than the left as you describe. NOW you need to measure the distance between the frame and the rear axle on both sides! Your spring may be sagging. You need to measure the body to the floor as well so see if there is a diffence between the frame to body height from side to side. Measure the frame to floor then the body to floor, then subtract the two. Do the same on the other side, you can find out if there is a body mount problem with that informaton.

Be sure that the front frame rails are level as well, there could be something happening at the front to throw off the back. Check tire pressure, check for unnecessary stuff in the trunk, etc.

As far as cracking the windows, you would have leave all body mounts tight and jack up ONE a number of inches to break a window, I mean a NUMBER of inches. This should not be an issue.

Also if your frame is bent and you shimm, you may have to adjust the rear bumper by oversizing the hole in the frame ( i will hear it for that one) on the side that was low to even out your bumper. Shimm the frame accordingly= say if the very back ( hypotheticly) is shimmed with three washers then move forward to the next add two shimms then forward to the next and add one. This way you will sit flat on the frame. You must measure on level ground (like MARTINSR said). Its no biggie. Like I said before watch your door jams.

If your frame is bent upward . Best bet take it to a frame guy and have a pull. That may be an easy one for them. Someone on here should have your frame specs. Or you can "REDNECK" it with a come-a-long.

Thanks again guys. I Have check just about all measurements on the garage floor. Front ride height on both sides is the same and checked as per assembly manuel and specification in service manual. I checked height from the bottom of the body mounts. The height of the body mounts at firewall are the same. The height of the body mounts at the center of door are the same. The height of body mounts just before rear wheel have a differance of 1/16" higher on the left side. Height of mounts near the rear springs have a difference of 1/16" higher on the left. The height of the body mount just to the rear of the tire have a differance of 3/8" higher on the left. And finally the mount at the rear is 1/2" higher on the left. Car sits level at the front, at the firewall, and at the rear windshield and margins at the doors, hood, and trunk are look good. The rear ride height measure from the bottom on the frame to the top of the axel shows a difference of about 1/16" and within specs; think the spring are OK. The trim height of the rocker panels at the front and rear is the same and within spec. I am thinking that when the car was hit in the left rear and the quarter panel replace that besides the frame being pushed up and not brought back to specification, that since the left quarter panel was left inplace with a full skin put over it that the panel and trunk floor also got pushed up and so that when they put the skin over it, the result was that the left side rides 1/2" higher. This bugs me everytime I approach the car from the rear. So my approach is going to be: 1. Have the frame checked and pulled down some if possible. 2. install new bushings etc. at the mounting points. 3. Re-check all measurements. And finally 4. Shin the mounts on the right side, starting at the firewall 0, mid-door 1/16", front of rear Wheel 1/16", Spring area 2/16 don't want to get the rear whindshield to far out of level, rear of back wheel 3/16', and the last mount 4/16". Any finally crank the left rear mounts a little tighter. What do you guys think.

Go for it! But the mid door mount has a tappered thread insert deal. You may need to make the hole bigger in the shimm to alow the body to drop back down on the frame mounts. You may not need it under the door. Try startung just aft of the door first.

Car goes to the frame shop next week for a check and adjustment if necessary and provided the pull won't fracture the present body?? Then will put in new bushings and add shims. And add new springs and control arm bushings. Hopefully there is a smile on my face by mid Nov.

If the Quarter panel was installed when the inner structure was not in the correct position it is very likely that something will have to give when if there are corrections to the rear frame rail or inner structure.
From your description the ride height is correct, or at least within specs.
On a level floor if you measure the rear rocker distance to floor it should be equal side to side, same at the front of rocker, side to side.The same is true for the corners of the frame at cowl and in front of rear wheels.
If the rockers are level, frame is level at corners, and you stand at the rear of car, and it appears out of level, something is distorted behind the wheels.
Sound like you have a good plan, Good luck. Karl

Yep, rockers are level at the front by the firewall and at the rear in front of the rear wheels and rear ride height is equal. The left rear body mount just behind the rear wheel is 1/2 " higher then the right mount. And the lowest and most rear part of the rear quarter panel is 5/8" higher than on the right side. So as you said think the truck area was distorted by a hit and the part of the fram on the left to the rear of the rear wheel was bent up. Just hope to get it closer to level than now.

By the way Karl, have you had any work done at the Lake Marion shop in Lakeville?

Know Bruce at Lake Marion. He and I both have the "Chevelle" affliction. He favors the 70 to 72 Velles.
I stick with 66 only.
He is a nice guy that knows his Chevelles very well. Can be trusted to do it right!
Bought a car from him last spring.
We both own Collision Shops in Lakeville. My shop is on 35W and Co. rd. 46. He is further east and south of me on Dodd Blvd, and Hiway 50.
Somehow he has figured a way, where he can afford to take in and repair the old stuff.
The only old cars I let in my shop are my own. Have multiple 66 Chevelles plus some parts cars.
Karl

Well I finally put in all new bushings and from the looks of the old one's, it was a good idea. But the shimming at the mounts did not raise the rear of the body on the right side to make it level with the left. What happened was the spring on the right side must have been compressed because the rear of the right side moved up from the frame, but the body did not move up as the frame moved down. Any comments? Then I took out the shims and the rear of of body on the right side is now only 3/8 " lower than the left side. Guess I will live with it, use a worn tire on the left side and adjust the bumper a little and add some air to the right rear tire.

use a worn tire on the left side and adjust the bumper a little and add some air to the right rear tire. Don't do that, the difference in tire height will burn the spider gears out of your differential. I read the last post four times and still can't make any sense out of the body and frame height problems you are having. The rear section of frame behind the suspension is fairly flimsy and will follow the body contour when bolted up. Maybe you should switch the rear springs from side to side and see if the problem moves with them. It's as easy as unbolting the shocks on the bottom and lifting the frame till the suspension seperates and the springs will come out. Bob

Thanks Bob, The right rear of the car is about 5/8th of an inch lower than the left. Car at some time had the left rear quarter replaced, don't know how much but the holes for the vinyl top are not there, so am guessing a full quarter with the orignal lower rear part of the quarter below the truck left in place. So am guessing the car was hit on the left rear with the result being the rear part of the body cage bent or the frame bent. Your right about the rear of the frame weak since when I shimmed the mounts over the rear tires and the ones just aft of the tires the bumper moved down, but the rear height of right side remained unchanged. When I relieve weight on the right rear spring both rear sides of the car move up the same height, so that doesn't solve the level proglem. Guess I'll try again, leaving all mounts to the rear of the tires out, shim the one over the rear tire on the right side and the two in between the front cowl mount and the rear tire and check the height again. The try new spring.