Torsion bar crossmember removal

[Ryansrt]

Hi Everyone! So my 72 Dart has a rotted torsion bar crossmember and needs replaced, I have all the replacement parts and a welder. Just not sure on how to properly remove the crossmember or the process that should be done to complete it right. Ps....torsion bars are already out, just need to remove crossmember with transmission in the car still.

 

[pishta]

I think most everything down there is spot welded, just look for the welds and drill them out.

 

[Pascamp]

The trans has to come out. The cross member is tacked to the floor all the way across and up over the trans.

 

[72bluNblu]

Remove the transmission. You’re going to have a heck of a time trying to work around it. It’s not worth it.

You’re going to have to put the car up on jack stands and support the ends of the frame rails. You’ll need to level the frame rails, and you’ll probably want to support the rockers too.

Once everything is level and supported you’ll want to take a bunch of measurements. You can use the chassis measurements in the factory shop manual, but you’ll want to know how your car actually measures out with you taking the measurements. If you have a brand new replacement crossmember, use a 3/8” drill to drill out all the spot welds on the old one and remove it. That will leave 3/8” holes in the floor pan, which will help you locate the new crossmember AND allow you to plug weld it with a MIG from the top side, which will make your life A LOT easier. If you have an original crossmember removed from another car you can use a spot weld cutter instead because the replacement crossmember will already have all the holes from the old welds being drilled out. But you’ll still probably want to drill a few all the way through. And welding from the bottom isn’t that fun if you’re up on stands.

Needless to say, measure a lot, tack a few spots, measure again.

 

[gdrill]

Pretty good descriptions above. The only thing I did that isn't mentioned was, I welded a solid structure between the frame rails and the rockers prior to removing the torsion bar cross member. This held everything where it originally was. Now having said that, exactly where it was isn't fully critical. It is truly surprising the tolerances the factory had. I have found quite a difference between cars.

 

[Ryansrt]

Also I have about 20 inch by 20 inch sections of floor pan cut out already too so it makes a little more room to work with but thanks guys I appreciate it

 

[72bluNblu]

Also I have about 20 inch by 20 inch sections of floor pan cut out already too so it makes a little more room to work with but thanks guys I appreciate it

I wondered about this. You need to brace this car before going forward. You can't just cut out large sections of floor pan and remove the crossmember at the same time and expect nothing to move. Unibody's depend on a lot of different parts for their strength, you can't just cut out a bunch a stuff at the same time and not have the chassis flex.

I would strongly recommend finishing the floor before you start on the crossmember replacement.

 

[Ryansrt]

I wondered about this. You need to brace this car before going forward. You can't just cut out large sections of floor pan and remove the crossmember at the same time and expect nothing to move. Unibody's depend on a lot of different parts for their strength, you can't just cut out a bunch a stuff at the same time and not have the chassis flex.

I would strongly recommend finishing the floor before you start on the crossmember replacement.

I will definitely brace it and some kid younger then me pulled it from a barn and cut where your feet go pretty much on both sides of the front so now the windows have small imperfections