Subframe connectors

[Muswagon]

Getting around to installing my competition engineering subframe connectors, I have a silly question.

Instructions say to lift the car and use jackstands, leaving the rear end unloaded. Why is that?

Reason I ask is the place I would use a jackstand on in the rear is exactly where the connector slides over.

I am sure there us another place that won't kill me, just more curious why you leave the rear end unloaded.... Chassis flex?

 

[Kendog 170]

Interesting. I would think you would have different results if left hanging unsupported in front of the leaf springs as opposed to the rear near the bumper. I would think supported loaded at the shock plate but what do I know. (Don't listen to me. Get more advise)

 

[Just Send It]

I was taught that when welding rigid frame pieces to a unibody, the car should be supporting its own weight on the suspension with the doors shut. Of course, that's assuming that everything is square to begin with.

Not sure if that's right or wrong, but that's how I've always done it and my cars go straight down Broadway. And my doors shut like they should.

Here's when I did mine. Race Ramp blocks so I had room to work, and the post lift held the connectors in place so I could weld everything

 

[crackedback]

I put them underneath, tack the crossmember plates and jack them into the bottom of the car.
If your doors are aligned well, open/close doors until you find the sweet spot. Weld them it in.
Do the other side.
It makes no real difference how you do it. Welded them in with the car upside down, sideways, on tires, on jackstands. Even took a laser pointer with a car on a rotisserie, right side up and upside down, nothing to even worry about either way. The tolerance they built these cars with are a looser than the town floozy...

 

[Muswagon]

I was taught that when welding rigid frame pieces to a unibody, the car should be supporting its own weight on the suspension with the doors shut. Of course, that's assuming that everything is square to begin with.

Not sure if that's right or wrong, but that's how I've always done it and my cars go straight down Broadway. And my doors shut like they should.

Here's when I did mine. Race Ramp blocks so I had room to work, and the post lift held the connectors in place so I could weld everything

View attachment 1716390099

Perfect! I have the same set of raceramps, and the older version of the maxjax, never thought of lifting it that way.

thank you!

 

[sam69sat]

These cars can flex. I've heard of doors not being able to open when up on a 2 post lift.

US Car Tool Frame Connector Instructions.

Hint #2. Do not weld your car with the frame supported on jack stands and the tires
hanging in mid air. Support the car on the suspension (under the rear axle tube and front
lower control arms is a good spot for Mopars) so it is “loaded” and have the doors closed
while you weld the frame connectors in.

https://store.uscartool.com/assets/images/Instructions/US%20Car%20Tool%20Frame%20Connector%20Installation%20Instructions.pdf

 

[Garrett Ellison]

I was taught that when welding rigid frame pieces to a unibody, the car should be supporting its own weight on the suspension with the doors shut. Of course, that's assuming that everything is square to begin with.

Not sure if that's right or wrong, but that's how I've always done it and my cars go straight down Broadway. And my doors shut like they should.

Here's when I did mine. Race Ramp blocks so I had room to work, and the post lift held the connectors in place so I could weld everything

View attachment 1716390099

Show-off! But I caint imagine any way of doing it that would be more correct than that. Man, I've got to upgrade my work environment...

 

[famous bob]

I put them underneath, tack the crossmember plates and jack them into the bottom of the car.
If your doors are aligned well, open/close doors until you find the sweet spot. Weld them it in.
Do the other side.
It makes no real difference how you do it. Welded them in with the car upside down, sideways, on tires, on jackstands. Even took a laser pointer with a car on a rotisserie, right side up and upside down, nothing to even worry about either way. The tolerance they built these cars with are a looser than the town floozy...

unless you have a great amount jacked into the supension , if it does , I`d jack the car up on leveled jack stands to make sure the preload isn't being welded int it , BUT , u may have to
realign ur doors --------I didn't !!

 

[Kendog 170]

I've done 2 cars with suspension loaded. I did hang the back of my Ragtop because I had tight gaps at the top of both doors and factory quarters. I was a bit nervous, but it came out great with even gaps on both sides.

 

[BrianT]

Following along. I have the same CE connectors getting ready to go on my Duster.

 

[abodyjoe]

I was taught that when welding rigid frame pieces to a unibody, the car should be supporting its own weight on the suspension with the doors shut.

me too and thats how i did my old dart. when finished doors shut as nice as they did before the connectors were welded in.

 

[Ozyduster]

You MUST have the load on the wheels. The guys saying weld them in with unloaded must not have used a hoist more than once in their life. Literally can see your door gaps change as it lifts car up. I had a holden monaro that is a chassis car and passenger door wouldn't open on hoist.
I built a tall timber frame that i sat car on and just dropped the hoist slightly lower so car unloaded.

Also i stitch welded my connectors as to not put too much heat in and avoid blowing holes in the floor. My engineer actually specked that i dont seam weld them on.

 

[mopowers]

You MUST have the load on the wheels.

MUST is way too strong of a word here. CAN or MAY are probably more appropriate. I've done it both ways and it worked out great for both. Doesn't matter how it's done. As long as the doors shut well and the gaps are good, weld 'em up.

 

[Ozyduster]

MUST is way too strong of a word here. CAN or MAY are probably more appropriate. I've done it both ways and it worked out great for both. Doesn't matter how it's done. As long as the doors shut well and the gaps are good, weld 'em up.

So you are recommending to literally stiffen a bow into the car? You "May" have done it however saying as long as the doors shut its ok.......... that sounds like a fairly agricultural build theory. Not sure why you would risk it given how simple it is to load the wheels up. Big difference between a door closing and a door with a perfect panel gap.

 

[mopowers]

So you are recommending to literally stiffen a bow into the car? You "May" have done it however saying as long as the doors shut its ok.......... that sounds like a fairly agricultural build theory. Not sure why you would risk it given how simple it is to load the wheels up. Big difference between a door closing and a door with a perfect panel gap.

Do you really think the bodies on these cars haven't sagged between the front and rear subframes over the last 50-60 years? This is an instance that people tend to overthink in my opinion. It's obviously been done both ways with great success. Pick one and go with it. If the panels align well and the doors shut well, burn them in. It's not worth losing any sleep or arguing over really.