Frame Connectors, Freaking windshield!

[4406bbl]

No suprise on the flex, these cars are bad for it. I would quit jacking it up like that unless you want the cowl to crack where the piller meets the cowl. Jack under the rearend, or k-frame only. If you do frame connectors make sure the car is square and level before you start. On a resto that lead seam at the cowl should be melted out and welded solid. I have seen cars put on 2-post lifts show witness marks in the paint at that seam. Every time you jack the car like that or 2 post lift it you over flex those welds, weakening them.

 

[ckessel]

Where do you place the jack? I've always either put it under the center of the K or center of the diff. Never had a problem. However, if the glass had a stress point from being too big or improperly installed, it does not take much for it to break. It would still be a good idea to put some connectors in but do them weld in which means interior removal.

 

[beanhead]

Sounds like the metal may have some fatigue..it happens. I wouldn't let anyone put a jack anywhere besides under the K-frame. #Jackstands can go right behind the control arms on the frame. This way the car isn't twisting sideways as it's raised, but going straight up like when you're popping wheelies...
Frame connectors should help and will definitely help with flex in the door area.

 

[ckessel]

Maybe you have a Monday or Friday car that didn't get enough welds or they were sketchy due to hangovers.

 

[mpro69rr]

Where do you place the jack? I've always either put it under the center of the K or center of the diff. Never had a problem. However, if the glass had a stress point from being too big or improperly installed, it does not take much for it to break. It would still be a good idea to put some connectors in but do them weld in which means interior removal.

I jacked it up behind the front wheel couple fee back. I can't jack it from the k member because I have a QA1 one. The company said I shouldn't jack it there. Already have the interior out so that's not a problem.

 

[mpro69rr]

Maybe you have a Monday or Friday car that didn't get enough welds or they were sketchy due to hangovers.

LOL, that would be my luck!

 

[Fran Blacker]

Two jacks one under each control arm?

 

[mpro69rr]

Two jacks one under each control arm?

That would work

 

[mpro69rr]

Thanks everyone for their suggestions and ideas!

 

[Dennis H]

A little off subject, but after the 440 was warmed up the windshield cracked on first romp. THEN, USCartool connectors were welded in. I never jack from the side. Dana or front crossmember.

 

[Runcharger]

So you're not supposed to jack on those fantastic aftermarket K'members? Another reason that &^%$ will never be installed in a car I own.

 

[mpro69rr]

A little off subject, but after the 440 was warmed up the windshield cracked on first romp. THEN, USCartool connectors were welded in. I never jack from the side. Dana or front crossmember.

I think that's what I'm going to do.

 

[mpro69rr]

So you're not supposed to jack on those fantastic aftermarket K'members? Another reason that &^%$ will never be installed in a car I own.

They said they would not advise it, but I may try and put a thick board under it to reach both cross members, then put the jack under it.

 

[StrokerSpanky]

I welded in the CNC cut frame tail connectors and torque boxes from US car tool and I'm really happy with them. Really stiffened the frame up. And didn't burn my paint. The factory put torque boxes on many old B bodies with Hemis and 440 six packs to prevent cracking the windshield during a hard launch. If you're worried about your paint cover it when welding and use a mig with argon/CO2 shielding gas. Very little splatter.

 

[ckessel]

Several years ago I was at the SEMA show when QA1 announced the new K frame. The first thing I asked the guy at the booth was "what happens when you put a floor jack under it to lift like you would a standard K frame". Gave me the deer in the headlights look for a bit then said as long as you put the pad under both tubes you "should be ok". I believe they never thought of that MINOR detail. That pretty much told me how great the unit is.

 

[MoparLeo]

Jacking instructions and locations are always in the front of the Factory Service Manual in the maintenance and lubrication section. Always refer to the FSM.

 

[70chall440]

I say again, something is not right. Unibody or not the car should not flex under acceleration/jacking enough to crack the windshield. I know the car is painted and all that but this issue needs to be figured out and dealt with as painful as it might be or it will be a problem forever.

 

[70chall440]

Jacking instructions and locations are always in the front of the Factory Service Manual in the maintenance and lubrication section. Always refer to the FSM.

And to that point if jacking the car up under the frame behind the tire breaks the windshield I can only imagine what is going to happen if a bumper jack is ever used.

 

[mpro69rr]

Several years ago I was at the SEMA show when QA1 announced the new K frame. The first thing I asked the guy at the booth was "what happens when you put a floor jack under it to lift like you would a standard K frame". Gave me the deer in the headlights look for a bit then said as long as you put the pad under both tubes you "should be ok". I believe they never thought of that MINOR detail. That pretty much told me how great the unit is.

I think it would hold, those crossmembers are pretty thick.

 

[Fran Blacker]

If you make something up like a bar not attached to car that went frame rail to frame rail. So you could jack it in the center of the bar. Is it possible the QA1 K member flexes more than a stock K frame?