yel76low

So a few questions...

How thick is the crossmember? What did you use to cut it out? I have access to a 110V plasma cutter, but I don't know if that will cut through or not.

How thick of plates did you weld on for bolting it back in? Will a 110V welder be strong enough?

Any suggestions, pics, etc would be appreciated!

Gordonm

Cut mine with a sawzall. Of course I work for Lenox saw blades so I have blades at my disposal. One blade cut through in no time at all. Be careful near the floor though. Easy to punch through the floor.

yel76low

I figured someone must have done that... but I sure don't trust myself enough!

What about the plates? How thick did you use?

Gordonm

I went a different way than the plates. I still had to weld some brackets on but I did not use the plates as seen here on the forum. Here is my setup. Not the prettiest but it works. I made the bracket for the back side and welded it on. On the front is a plate. In the frame I made some sleeves so when I tighten it down it will not crush the frame. The frame is quite thin and easily crushed. Cost me nothing to do this. I had the steel and got afriend to do the minor welding.

Dustup7T2

Hey Fellas:
I've been contemplating doing this project. I have a TKO600 to slide in and the thought of wrestling it into position on the fixed trans mount doesn't sound appealing while lying on my back [w/longer tailshaft than Muncie]. I bought the kit from Keisler and I know they engineered it to work with a fixed x-member; this way just has to make it easier.

Plus, I'm considering future clutch maintenance where I would not want to yank the motor.

Thanks for the picture Gordon. I've seen another design (may be the one you mentioned) that has flanges welded on tunnel-side ends of x-member "stubs" as well as the removable section. Then they're bolted together. It's strong but can't see how to get weld 360 degrees with body on. Or is 270 degrees (sides-bottom) enough?

My concern lies with doing the work body on; you expressed caution during cutting w/sawzall. What about welder heat transfer (rising) onto a non-steel floor? How did you control or not really an issue? I haven't crawled under my car to check and wonder if some type of barrier can be slid between x-member and floor to protect?

I like how Gordons work resulted in a stable platform; cheap is great too. I saw Shafi Keisler has a slick new x-member kit offered too but like others, disposable $ is becoming more of an problem lately. Ugh.

My sbc doesn't have tree-stump-pulling torque and with the sleeves you built into your design, I imagine it's plenty stout. I'd like to plan how and appreciate starting this post. I'll follow along and see what happens.

Thx!

yel76low

Any particular reason you chose to do it that way? I wouldn't even have thought of that.

Your sawzall cuts look very clean. How thick do you think the crossmember is? 1/8"?

carriljc

If I were to do it again, I make the cuts further inboard.
As far cutting, just use a sawzall or a circular saw. I used a rope saw to cut mine, but there's no need to be that accurate.

All stitch welds completed and painted this gray that I really like.

72LS1Vette

Here is a pic that shows the thickness of the crossmember metal. I think the thickness is .10" but I could be mistaken. For reference, the stock I used for the mount is 1/4".



Rick B.

yel76low

Thanks for all the pictures everyone.

So the consensus seems to just use a sawzall, and be careful by the floor... Now what about welding onto the stubs? Like was said before, we're aweful close to the body...

carriljc, I like the tabs that don't go any lower than the crossmember. Do you have any pictures closer up from a different angle on the end of the crossmember?

silverslashstreak

A sawzall works very well and makes a nice cut. Here a couple of pictures of my removable cross member. I don't like to weld on stuff with the car body so close, so I drill 2 holes on each side through the left over cross member and the channel iron I welded to the removable part of the cross member.





When it is bolted in you don't really notice it is home brewed.



Jeff

yel76low

Jeff - got any pictures from under the car to see what it looks like? I like that idea of not welding right up next to the body.

captl27

If you have the body off the frame you can grind back the welds on the ends where the crossmember meet the frame and then separate the cross member from the frame, add to ears to the part under the frame and drill 4 holes two on the top side and two from the bottom. (see Pics) then weld in tee nuts and bolt it back together

68 NJConv 454

Very clean, I like.

Gordonm

I did no welding on the frame on the car. My bracket is welded to the removeable part of the X member. I only had to drill the frame on the car. My trans is out at the moment. I can take a picture of it later today to show you exactly how it was done. Like Isaid it is not pretty but it works just fine. It stands up to 500HP so far with no problems.

carriljc

Pretty much straightforward though...cut the crossmember, used some 1/4" plate, ensured the width by grinding away after the cut. For the stub left on the vehicle I just welded the top of plate to the top edge of the stub (while making sure that the fiberglass floor was shielded)...after I made sure I had a good weld then ground it so it was flat.
The remaining 3 sides are welded at the 90° angle so it's quite solid. I initially had a "lip" over the vehicle stub, but I ground it off; not necessary and I used Grade 8 bolts.

silverslashstreak

I will try to get a picture today. By the way I have the machine shop slice a piece of 4 inch square tubing in half and the inside width fits the cross member perfectly snug.

Jeff

rebc3

i see a few mentions of cuts NOT needing to be accurate. this is gravely wrong. the guys who are doing the side plates are probably ok, but those of us who are welding end plates need to be VERY accurate. if you dont get the mount back in the right location from left to right, your driveshaft will hit the floor/tunnel. especially under load. also you must make certain that you angle is correct. meaning the trans mount on the crossmember must return to the same angle/plane as it was before the cuts were made.
and i dont think strength is as big an issue as it is being made out here. you dont need to weld all the way around. if you cant put some scrap sheet metal in between the floor and the top side of the mount, just dont weld it. our crossmembers are enourmous and incredibly strong, even for performance engines.
this mod has been one of the best things ive ever done to my vette, especially after i got the tko 600.

carriljc

Nothing hangs lower than the original crossmember.

69 Convertible

With the encouragement from Gordon I bit the bullet and made my crossmember removable. I copied Bullsharks design, but rather than making the flange open in the center, I just had a full flat plate welded. In cutting the crossmember, I used a square to scribe a line and use tape to tape where the line is so I could try to keep the cut straight. The bottom was easy to cut but the top was alittle harder. After using a 6 inch blade and smashing my finger, I switched to a 9 inch blade. Cut in an angle. With the 6 inch blade, it was too short and would come off the top of the crossmember causing the blade to kick back which kickback the gun. In welding the plate to the crossmember on the car, I got some copper sheets, damp rags on top of it to protect the floor. I had a coworker help me weld it. Before you cut the crossmember, make sure you take some measurement of the trans mount bracket to the frame toward the door.The distance from the drivers side and the passenger side are different. When I had to trim off some metal from the crossmember on and of the car, I forgot to take the measurement. So I didn't know where to weld it. Gordon help me get back on track. You dont want your trans to be off.





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rebc3

that is exactly what i did!
but whats with the ground straps? please dont say to ground the cut section of crossmember, as the new plates are touching AND it has 8 bolts holding it together!