Checking body/frame alignment at home

[hanksemenec]

I had some fun reading through the service manual. The procedure does not look too complicated. The fun part was they were using a plumb bob. +/_ 1/4" tolerance. I can get the same measurements done with 360 deg. self leveling laser. Anyone tried this at home? I can level the car, and use the laser to mark the points on the floor then take the measurements. I can even map the floor flatness, some math and correct for floor slope if any. After the horizontal I should be able to set the laser under the car and measure the vertical position of each point to datum line. WTH could be fun. 

[JS29]

Lazar systems are great, have fun and enjoy. 

[hanksemenec]

Well this exercise really paid off. Car is level.

Front is actually straight, it was repaired by someone that knew what they were doing.

Rear is a different story. Rear was hit on the right.  Frame was sectioned near the trunk cross-member. Right rear tail of the rail has a 1/2" drop compared to the left side rail. The tail panel and everything else is 1/2" lower on the right.
Well that explains why the car looked twisted.

Good news, the roof structure is straight and a&b pillars are good too. 

[1 Wild R/T]

Well this exercise really paid off. Car is level.

Front is actually straight, it was repaired by someone that knew what they were doing.

Rear is a different story. Rear was hit on the right.  Frame was sectioned near the trunk cross-member. Right rear tail of the rail has a 1/2" drop compared to the left side rail. The tail panel and everything else is 1/2" lower on the right.
Well that explains why the car looked twisted.

Good news, the roof structure is straight and a&b pillars are good too. 

Allot more common than you would think.... Back in the 90's I knew of three cars locally that weren't square....

[hanksemenec]

On one aspect I'm lucky. The rail is welded in square, the rear right to left front shackle mount matches the rear left to right front, only the elevation is off. Previous owner put in the trunk floor, but he stitch welded the floor to pan from the bottom to hide the work, it will be easy to release the welds. Quarter has to come off anyway and the wheel well might as well come off too, it is damaged.

[torredcuda]

Since I do a fair amount of bodywork at home I`ve thought about getting some type of laser and doing that, I`ve had a few cars that were hit and repaired in the past. What laser are you using?

[70 Challenger Lover]

This car was in super bad shape. The front end was straight but rusted out so initially, I put the car on jack stands and rails to take accurate measurements as I put new front rails on. I even used your plumb bob style to ensure shock towers were angled equally side to side.

On the back, the car took a light rear end impact but because everything was so rusted out, it crumpled like an egg shell. The rear rails needed to be replaced so I built this rack to place the car on for precise measurements. As it turns out, I discovered the rear rails got pushed up ever so slightly in the collision. Not enough to see inside but with the new ones attached, the floor sat two inches too high at the rear tail panel. I saw this coming so I purposely did not stitch the seat back panel to the sides of the wheel wells when I welded in new rails and wheel wells. In the last picture, you can see straps from the rear shackles and I used them to gently pull the rail assembly down. Fortunately, the rack I made is so thick and heavy that it was easy to anchor it at the front end and use for light pulls like this. The floor goes in next and gets further strength as I weld it to the wheel wells.

If everything comes out as planned, I should be able to get the floor, tail panel, quarters and drop offs to all play nicely together. I have no doubt it will be good.

The laser thing sounds nice. Wish I had one and knew how to use it.

[hanksemenec]

I use a tripod and https://www.amazon.com/gp/product/B0727RX8PD/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 (SC-L04), mine is a little older, and there are other similar levels.

Level the car: I use QuickJack, since I'm old and tired of jacking the car up. I surveyed the floor for the drop at the pick up points. Set the level under or on the side of the car, so you can illuminate area close to
jacking points. Set level to horizontal beam. Take beam to floor measurement, record the numbers. The lowest reading is your floor peak. Calculate shims needed at each point ( tape measure reading - peak point = shim thickness)
Cut plywood shims and put them under lifting blocks. I use 4 more jacks to pickup the rails when doing work.

Horizontal measurements: Set the level to vertical beam, place the level under the car. Move the level to position to mark the datum point center line (x direction), rotate level 90 deg (y direction) mark the X spot on the floor.

Vertical measurements: Set the level under the car, switch to horizontal beam. Use a tape measure with a magnetic tip, put it on datum point and hang it, then take your elevation reading.

With the car level, pick points on the car that appear to be still intact, like roof frame, a pillars, c pillars and etc.  Measure the distances, half them and try to mark center line(CL). Align the vertical laser with the CL. You can check the symmetry of the body panels.

With the horizontal beam and car level you can check the level of roof structure, fenders and rear. Just move the laser to the right elevation and look at the beam intersections.

[Topcat]

Last week I visited Hank.

He has a pretty good  project to work on. 

Here's a pic of the right rear inner fender.
It was the main concern when we talked.

[hanksemenec]

Hats off to the bondo sculptor. Same car!

[JS29]

When a car is receiving a vinyl top, the filler  work is marginal at best!