[Rock-It Man]

The pinch welds are stronger and stiffer than the sheet metal on either side. That's why all car manufacturers designate them as the best lift points on unibody cars.

The lift blocks that straddle pinch welds and load the horizontal sheet metal next to them were designed by people who don't know structural design, sorry to say.

[vtirocz]

Originally Posted by Rock-It Man

The pinch welds are stronger and stiffer than the sheet metal on either side. That's why all car manufacturers designate them as the best lift points on unibody cars.

The lift blocks that straddle pinch welds and load the horizontal sheet metal next to them were designed by people who don't know structural design, sorry to say.

I agree.

[Gunkk]

Originally Posted by craigss50

Does anyone know what the difference is between the convertible and the sedan as far as pinch welds? You can get bolt on for the sedan for under $50 but if you have a convertible it looks like ZL1 Add Ons is the only company that makes them for the verts and costs $94.

There's a difference in the "depth" of the pinch weld on one side (height of floorpan vs height of rocker). The unique door frames for the vert come with extra steel on the outboard side to support the x-brace and add stiffness. The ZL1 Addons Vert pads are cut down on one side so they properly fit this beefier panel at the pinch weld. If you don't cut down the outboard side, the set screw will not engage.




(edit - added a crappy photo but you get the idea)

[Emoto]

Originally Posted by Racerman27410

The fender damage that i've seen doesn't come from the pinch weld lift pads . The dealerships use a two post lift that has arms that swing under the car. When the lifting pads on those arms are not adjusted correctly then the arms of the two post lift will make contact with bottom of the front fender
and bend them before the lifting pad makes contact with the subframe/ chassis of the car.

Has nothing to do with the strength of the pinch welds and everything to do with techs not paying attention to details before lifting the car.

Thank you for this excellent description of how the damage can happen.

[MatthewAMEL]

Originally Posted by Rock-It Man

The pinch welds are stronger and stiffer than the sheet metal on either side. That's why all car manufacturers designate them as the best lift points on unibody cars.

The lift blocks that straddle pinch welds and load the horizontal sheet metal next to them were designed by people who don't know structural design, sorry to say.

You mean other than the ZL1Addons product? They DO NOT make the area around the pinch welds load-bearing. They simply make the area of the pinch weld easier to access and get a lifting device on.

[az4783054]

The provided 1/8" allen set screws are a PITA to tighten since they're so recessed within the pucks. Longer set screws may be available (?).

I replaced them with hex head grade 8 bolts. I believe the thread size is 1/4-28" to allow a better grip and torque without stripping out the recessed set screws. I also inserted 1/8" aluminum shims behind the fasteners to prevent the fasteners from digging into the pinch welds.

[zaimer]

Originally Posted by az4783054

The provided 1/8" allen set screws are a PITA to tighten since they're so recessed within the pucks. The unibody floor boards are not flat which prevents using just about anything but an allen wrench. Longer set screws may be available (?).

I addressed that by replacing them with hex head grade 8 bolts. I believe the thread size is 1/4-28". With those, one can get a better grip and torque without fear of stripping out the recessed set screws. I also inserted 1/8" aluminum shims behind the fasteners to prevent the fasteners from digging into the pinch welds.

The ZL1 ADDONS pucks may be more to prevent the pinch welds from being deformed laterally when lifted.

Thank you, I'm glad I'm not the only one who had struggled. They weren't terribly difficult but it was enough to say "c'mon on now".

[Gunkk]

You can get 3/4" stainless set screws on amazon.