puzzling body twist Options

[doug_b_928]

Sorry in advance for the longish post. My 73 was hit before I bought it as a naive kid of 15 (the car was badly rusted and poorly repaired or not repaired at all, more than 30 years ago). A few years ago I set out to begin the slow process of restoring the car only to find out how extensive the rust is and that the chassis is twisted. I wish I could drop it off to Rick or Scotty but that's not in the budget (especially with the exchange on the CAD). I know I should abandon any hope of restoring it, and it may well become my parts car, but it keeps sucking me back in.

Case in point: When looking at the car from the rear the twist is obvious, it's 1.25" higher on the passenger side. I've done the measurements on the car and the only part that's off is the rear end. The trunk is square but the 'length of rear body assembly' (q measurement) is 8mm short (and, as shown below, shorter on the driver's than passenger's side as well), the width of the trunk opening (r measurement) is a bit wide at the top (2-3mm), perfect at the point above the transmission crossmember, and narrow at the very back (-7mm). The diagonal across the trunk (s measurement) is square but 8mm short.

I also measured from various points under the car down to a flat surface (trailer floor) and was quite shocked to find symmetry side to side all of the way from the firewall back to the transmission crossmember and even a bit past that point. As well, I measured these points from the firewall and to the suspension mounting brackets and found symmetry.

I was able to check measurements on another shell that does not appear to have ever been hit and they were either identical or almost identical to mine (except the ones that are off on mine mentioned above).

The PO had put in a homemade engine bar, so I theorized that perhaps the bowing of the front of the fenders meant that the engine mounts bowed as well, but I acquired an engine bar and it fit like a glove. Then I thought that perhaps the trans mounts were shifted (necessitating a custom engine bar so the trans would mount), but the symmetry side to side from the attached measurements below as well as the consistency with the measurements I took from another shell suggest that's not the case either.

This all suggests to me that the car is only twisted at the very back, including the rear trunk floor pan but not the trans crossmember. Even the pinch weld of the "frame" a bit behind the trans cross member is not different side to side as measured to the floor of the trailer. The fender(s) are pushed in at the very back and maybe slightly bowed toward the front (at the bottom front the fenders they are bowed significantly past the doors). The inner wheel wells in the trunk area are also off from one another a bit in terms of height from the trailer floor, but not by much (I calculate at most 5mm).

Attached are my measurements (that are supplementary to the ones on the list of 'Body Dimensions' as well as some pics that show the asymmetry in the rear of the car. It is clear that the rear trunk floor was pushed in, it took the hardest hit on the driver's side and there is a poor patch on that side (but there was also damage to the tail light area of the passenger fender). Looking from underneath you can see the difference in distance between the underside of the trunk floor and the tail section. It almost looks as if they welded on a different tail section crooked, but given the repair I doubt that any panels were replaced (even the broken tail liight housing was re-used with puddy to seal it up). When you look from the back of the car into the trunk you can see how crooked the tail piece is in relationship to the trans crossmember (see pic below).

So I have all of these data but I still can't figure out whether the driver's side is low or the passenger side is high, or both. Does anyone have any advice on what I can do to figure that out? Do the pics below showing the difference in distance from the underside of the trunk floor to the bottom of the tail piece give any clues?

Here's the view from the back where you can see how the tail section is off relative to the trans crossmember:



Here's a view of the underside where you can see, sort of, how the distance from the underside of the trunk floor to the bottom of the tail section is quite different from side to side (it's more obvious in real life):



Here's the view from the underside of the dirver's side:



Here's the view from the underside of the passenger's side:



I'm hoping the latter two pics might give some clues as to which side is (more) off.

Here is a pdf attachment of the measurements that I took:

 914_Supplementary_measurements_June_1_2016.pdf ( 1.06mb ) Number of downloads: 728

[doug_b_928]

I've finally had some time to work on this (IMG:style_emoticons/default/sawzall-smiley.gif) (It took a lot of planning and thinking; even waking up in the middle of the night designing tools to do the job). I think I have the car straight. I'll know better once I get the donor quarters and tail section from the shell I'm getting from Rick.

I made a jig out of threaded rod and couplers. I made it so that I can bolt it to, or remove it from, the bench attachment that supports the rear of the car. Once I had it made, I unbolted the attachment that supports the rear of the car and bolted it to the trans mounts of the another shell that a fellow 914World member has in the city (Many thanks to 914World member Krank!). Then I set the jig per the shell. Then re-installed the jig on my bench.



I should have used 5/8' threaded rod so it would be much less flexible and more precise, but it served the purpose for me to show me where my car was off. As you can see by looking at the tail section, which is set by the jig and suspended by a rack that I made (I'll also use it for hanging parts to prime and paint), the right side is correct and the left side was low (see how the tail light area is 1.25" low on the left; also note how the tail section is straight relative to the inside of the trunk).



So, time to do some bending. I had to make a hold down to counter the force of pushing up the left rear. I used vise-grip pliers, with the adapter from my slide hammer, and made a receiver for the chain hook out of a large bolt with the correct fine threads that the slide hammer has and two washers welded to the bolt and to each other. Then chained and anchored to an existing anchor in the floor. It worked perfectly.

I marked measurements on the tops of the inner fenders based on distance from the trunk seal flange at the front of the trunk where it meets the inner fender on each side. I then used a straight piece of metal with a plum bob hanging off of each end, set the piece of metal on a given measurement on both sides, and measured from the piece of metal down to a straight bar resting on the bench. That way I could check the measurement of each side relative to the true bench.



Then came the porta power.





The car is now straight. I put some tape on it to assist with seeing some of the lines, but the tape is sagging. This pic is not perfectly square, but it's pretty close. As you can see, everything looks pretty good relative to the bench.



Finished off with some hammer and dolly work to smooth out the crash damage.

Before straightening



After



I'm not going to weld the crack etc. because there will undoubtedly be some adjustment needed once I get the new quarters (I just hope I don't need to make any major adjustments again).

Overall, for my first attempt at doing something like this I'm pleased with the result. Now that this is done I have to undo some of the poorly done repairs from more than 33 years ago before I can start the undoubtedly long process of making my own rust repairs.