I'm already kicking myself for not making the transmission xmember on my 68 vert removable when I did the body off resto.
Today I had to pull the 4spd trans as for some reason the damn plastic speedo gear is loose inside the tranny, no idea why and didn't want to grind it up so out comes the tranny...but having that manual xmember in the way is driving me nuts.
So I'd like to hear some options.... (I have hooker sidepipes)

1a.) Does anyone make a tubular xmember for the stock 4spd? Bowtie does not.
1b.) If so, I would assume the trans xmember is very important to the structural integrity and ridgedness of the frame. (well as rigid as it can be). How would a tubular xmember with only two bolts per side serve as a structural member to prevent the frames twisting motion?

2.) If I fab up something on my own it will closely resemble the below that I found on the "other forum" as it only requires me to weld off the car and the cutting won't require me to raise the body.


I was considering the below method and finding someone who could sell me the plates however I don't want to weld the xmember on the car near the floor nor do I only want to be able to weld three of the four sides.



And lastely, anyone have any links to these strong manual transmissions that are being talked about on here with these hi-perf builds? I think they're refered to as Transzilla and transzilla jr? I'd like to read up as I've always wanted to get better gearing and mpg but have confidence the trans can handle far more than I'm throwing at it which is a hair over 600 at the moment. Gotta get it on my wish list for xmas 2012.

Thanks,
-Brett

 

I have seen a few that were cut 90 degrees and had a flat 4 bolt flange welded to each piece.

You could also source an auto x-member and adapt it to the manual frame. It uses 3 bolts on each side - 2 are on the bottom and connect to the frame rails and 1 mounts horizontal thru tangs mounted on the interior of the rails.

Good Luck, Ed

 

The 45Deg. out at the rails is a good idea , like GM did it for the Auto. I layed out different ways and came up with the one you see in the Pic. 1. It was easy to have the removeable piece 14" span, all the bolt up and removable right in front of me. 2. I had to notch the drivers side exaust hole so decided to cap them Both for superior Torsion strength, not at all Necessary, I have a side mount exhaust so made the caps a bonus addition.

Ive dropped the tranny 2 times in the Past 6yrs for engine upgrades and Im Happy with the way I modified the crossmember. I can easly drop the Tranny alone, from under the car on jackstands and reinstall just as easily.

In all honesty the 45deg. cut and attach to the frame rail like GM did it is just as good, Possibly Better? It may take more time and hands to remove and reinstall the tranny that way, but dont know that for sure.

Good luck with the new tranny, the 6speeds are the best thing you can do for a C3 with an engine upgrade.

 

Had another thought...do I have to worry about frame recoil when I cut this xmember? I have the front wheels chocked in up on ramps and jack stands holding the rear of the car up right under the #3 body mounts (in front of rear wheels).
I sure don't want to be under this thing if its going to wiggle when I finally cut the xmember.

Kwik lift would be ideal right now if only I had the $$.

Thanks
-Brett

 

When I initially cut and modified, it was on a lift there was no recoil or springing. When I removed it Both times , I was under the car on jack stands , No recoil, and No spring.

PS you dont want to Buy the Flange Plates..youll need to measure ,Cut and weld to fit . If you do it like GM, you wont need to be as exacting.

 

I cut my C2 frame (same as C3) at angles just as you show in your diagram, approx halfway between the exhaust holes and the side frame rail. Then I used 4" aluminum square tube which fits exactly (tight) over the original cross member to support it and drilled two 3/8" holes each side of the cuts, so a total of 8 bolts hold it all together (4 each side). Aluminum square tube is actually c-channel, 4" outer dimension with 1/4" wall. The sides of the square (c-channel) should come up about 2".

I would note that I was unable to cut my cross member without raising the C2 body a few inches for saws-all clearance. I tried, even had it on a lift, but no joy. But in the end, I have a removable cross member and never had to weld. Your idea with an inserted support should work fine also, but I would use two bolts on each side.

Good luck!

 

I cut the old one out and bolted the new one in. Have to make brackets. I can put a wrench on and un bolt from holes i cut out.

 

Here's a pic of a friend's removable cross member fabricated onto his 69 coupe.

 

You can see the first version of my removable crossmember. Just used end plates. What I did to allow a full weld was to leave a small lip at the top of the *stub* on the frame so that the upper part could be welded on the *plate side* along the top and then ground down smooth. I sed 3/16" plates that I made.

This year I got tired of having to put exhaust through the holes and wanted to install 3.5" pipes. I had a local circle track shop bend a tube ($40) and I added new plates and built the trans mount and emergency brake mount. Now I can go straight off headers for pipes with no bends!








JIM

 

Well, here's what I ended up doing. Went with the first diagram of my original post as that was easiest and would suffice. I didn't feel comfortable welding the plates on the xmember that would stay attached to the car...I would have only been able to get to 3 sides and I'd have to get all the holes to line up exactly each time i reinstalled.

This mini sawzall was absolutely amazing and made the install go very smoothly. Cost me $99 at home depot, has a bright light near the blade and speed varies how far you push the trigger. You can flip the blade over for more clearance. No way I would have been able to manuver a big sawzall with the car only 1.5 feet off the ground.
Look how small it is when compared to my large workglove!



I used the cutoff wheel to get the first cut then I could insert the sawzall blade into the hole and start cutting.
First cut, I used the tape and a measuring square to try to make the cuts consistent on both sides.


In order to cut the top to connect the diagonal cuts I had to cut down without cutting the floorboard. I will fix these cuts with the welder.








And the trans is out!


Now i have to find some 3"x3" square tubing and fire up the welder.