Question about installing sub-frame connectors

[paddyrk]

Hello all,

I have full length sub frame connectors with the seat brackets ready to be installed on my 1991 Lx 5.0 as soon as it gets back from the transmission shop. I have heard people say both you can install them with jack stands and that you need a drive on lift. A shop owner near my city that has built his own Indy car and done plenty of work for NASCAR and works on million dollar plus cars daily said that I could install them with jack stands, but people on forums and LMR say should really use a drive on lift. I will be bolting them in for now unti lI can have them welded in by someone that actually knows how to weld.

Bottom line, is it okay to install sub frame connectors without a drive on lift? I.E. using jack stands.

Thanks

 

[JD1964]

I would stick to whatever the manufacturer instructions for installation are. Furthermore, if welding is the final plan, I'd wait and just weld rather than drill holes in the car body.

 

[Mustang5L5]

Usually most want the SFC's installed on a drive on lift. The idea is that the tires are all flat on the same plane, so the chassis is in its nuetral state. When you use post style lifts, or jackstands, you can't be sure that the stands/lift aren't tweaking the chassis out of it's neutral state and the last thing you want to do is weld the SFCs with the chassis tweaked. That's when doors don't line up and close properly

 

[Davedacarpainter]

The weight on the suspension thing mainly has to do with the weak bodies our cars have.

I'm able to weld mine on with jackstands, but it's a shell right now. No drivetrain or anything to help tweak the body.

No disrespect meant to you friend with his experience. These cars are just noodles.

You can do it on jackstands if you place them under the suspension. Meaning under the rear axles close to the wheels and close to the front control arms.

If you place the jackstands under the rear torque boxes and the front subframes, your body will bend slightly. It will stay that way once the sfc's are welded in. Some people actually have issues with their doors opening and closing while on jackstands like this.

That's all it is. Not rocket science. Just weak subframe architecture.

 

[kendawg73]

The weight on the suspension thing mainly has to do with the weak bodies our cars have.

I'm able to weld mine on with jackstands, but it's a shell right now. No drivetrain or anything to help tweak the body.

No disrespect meant to you friend with his experience. These cars are just noodles.

You can do it on jackstands if you place them under the suspension. Meaning under the rear axles close to the wheels and close to the front control arms.

If you place the jackstands under the rear torque boxes and the front subframes, your body will bend slightly. It will stay that way once the sfc's are welded in. Some people actually have issues with their doors opening and closing while on jackstands like this.

That's all it is. Not rocket science. Just weak subframe architecture.

I was kinda wondering the same thing myself, I have MM full lengths to put on.... my thinking was to do like you said, put the jackstands on the rear axle, and under the front control arms... which, would put all the weight on the suspension just like it was sitting on the tires...

But here is my concern... where I have my car parked under a car port, it's not totally level, it has a slight slop to the left... which unless I'm wrong (been know to happen a time or two... lol) shouldn't really matter since everything is still sitting on the suspension and it all moves anyway... So will that work, or not?


if not, then that's going to suck... I wanted to get that down once I got the drive train put back in, and before I put the new carpet in ect...... will be awhile before it's moving under it's own power..

 

[Mustang5L5]

I was kinda wondering the same thing myself, I have MM full lengths to put on.... my thinking was to do like you said, put the jackstands on the rear axle, and under the front control arms... which, would put all the weight on the suspension just like it was sitting on the tires...

But here is my concern... where I have my car parked under a car port, it's not totally level, it has a slight slop to the left... which unless I'm wrong (been know to happen a time or two... lol) shouldn't really matter since everything is still sitting on the suspension and it all moves anyway... So will that work, or not?


if not, then that's going to suck... I wanted to get that down once I got the drive train put back in, and before I put the new carpet in ect...... will be awhile before it's moving under it's own power..

You'll need to level it. Long straight edge and son thin boards to try and level out the base of the jackstands.

What you plan to do is how I'll do mine eventually. They key is to level the jackstands. Check your door fit too first before welding

 

[VibrantRedGT]

They need to be installed under load according just about every SFC Manufacturer.

If you can put the car on ramps in all 4 corners that will work.

Hanging on jack stands, I would avoid that.

 

[kendawg73]

yeah, I didn't think of that... I'll just let it down onto ramps.... but guess I would still need to level it, and raise the drivers side up (since the driveway slants left) by putting some thin boars under the left side ramps I guess...

 

[Davedacarpainter]

Level is important.

 

[mikestang63]

car needs to be level and with the full weight of the car loaded or you will weld them in with the car tweaked and cause all kinds of issues.