Transmission Cross member

As the floor install progressed, I began to consider the things I should probably take care of while I had the access. I had installed the frame connectors. So much easier without a floor if you don’t have access to a rotisserie.

I wanted to lock the drivetrain in at it’s 3 degree tail down position. Once set it was better to lock it in with a cross-member sooner than later.

I tried to use the existing cross-member but I couldn’t figure out how I was going to pull that off without the transmission tunnel support to fasten it to.

The conclusion I came to was that I would have to build my own from scratch.

I cannibalized one of the discarded transmission tunnel supports and used parts from it to make the chassis mounts for the cross-member. Took some rough measurements using the drivetrain as it sat in the car and applied those to the floor supports and then welded the mounts into place.

With that taken care of I could start the process of making the cross-member itself. How the hell am I gonna do that?

I made some templates out of cardboard. I was thinking of different designs I’d seen over the years and tried to come up with something that would hold the transmission in place and allow the most clearance for the exhaust

I salvaged a mount I had made from an earlier attempt at making a crossmember that would work with the trans tunnel support still installed.

With the drivetrain at its 3 degrees down angle, I bolted the trans mount to the transmission. Using the floor support mounts and the reused transmission mount, I was able sketch out a shape for the cross-member sides

From the cardboard template came the steel pieces made of 1/8” mild steel. The width of the crossmember was dictated by the width of the side mounts and more 1/8” steel was cut to size.

The skeleton of the cross-member was assembled and, as always, checked for fit under the car before fleshing it out.

I used masking tape to make a template for rest of the cross-member parts. From these I was able to cut the metal plate to length.

I used a piece of thick wall pipe as a forming brake to put a gradual bend in the plates. There was a glint of an idea to form the plate exactly to the cross-member but that passed.

With a bow in the plate, one end of the plate was securely tacked into the inside curve of the cross-member. The plate was gradually pressed in to the cross-member until the face of the plate was even with the edges of the frame and then tacked into place so it would hold its position.

For the outside curve, there was no pre-bending. The plate was tacked in like the others and then pressed around the outside curve and tacked into place as before but when the bend became too great, a dead blow hammer was used to coax the plate into shape. Quite a bit of pounding and then pulling to get the pieces aligned but I was having fun watching this thing come together.

Did a little boxing in of some areas and then the usual test fit. When it looked like there was no more work to do in it, it got spray bombed.

So there it is. I accidentally put a dent in the top when I was “adjusting” it. After all of the welding, I found that there was a slight twist to the cross-member. I had to use a bench vise and huge crescent wrench to get the twist out of it.

Yeah, the dent bums me out but I ain’t putting more time into this thing than I already have. There’s way too much other stuff to take care of to get this car back on the road again.