I used the rectangular BMW pucks.

 

I'm sure the engineers didn't design these secondary outer rail lifting points for lifting the whole side of the car.

 

I would guess your jack/jacking stands are making contact with the outer frame, not just the pucks. The rectangular BMW pucks have indentations and you can machine jack and jack stand ends that fit into the indentations. No slippage and no contact with the outer frame.

 

I've noticed same thing.

 

I'm and engineer and I would have to agree with you. Why would there be two lifting points on each side?

 

The frame lifting points are to accomodate a 4 point commercial lift.

Shadetree mechanics would be advised to use the preferred frame lifting points.

Given how thin the C6's hydroformed frame is, a larger lifting pad which will distribute more of the force (ie: BMW rectangular ot hockey puck) may be the way to go for 4 point lifting or the occasional single frame point lift for wheel removal.

 

I almost hate to post this
:o
But I will for the sake of those who use pucks at the track.

Listen to the first 30 seconds. Video sucks, my camera was messed up but I did catch the noise starting from the front Left, going back to the right rear and then getting caught up in my wheel.



Messed my caliper and wheel up big time. Cosmetic damage only but

I iniitally thought it was something from the track until later in the day I went to jack the front up, went to get a puck and it dawned on me,
"You dumbarss"


My advice for the day
DO NOT FORGET TO TAKE THE FREEKIN PUCK OUT.


I am just very lucky it did not hit someone behind me.

 

Some pucks can remain installed (for example plastic BMW). I assume you used aluminum pucks or home made pucks with eye bolts that need to be removed? Sorry about the damage.

 

I did jack my car up a couple of times using only the rear puck location BUT as a rule I don't do that. I found out by accident that jacking from the rear location will raise the whole side of the car. This occurred when for what ever reason, I jacked up my car starting at the rear driver side of the car. I already had my puck installed in the front location as was certainly going to use it. To my surprise, both wheels on that side of the car were lifted off the ground as I raised the jack under the rear puck.

The word of advice here is: When using jacking pucks, always start with the front end of the car and then proceed to the rear. That way you won't be tempted to use only the rear location.

I doubt the shape makes a difference since any puck is still fairly small in size so the point of contact is concentrated. I strongly believe that what the puck is made of is much more important. Aluminum pucks are not good at all in my opinion. Rubber pucks is the way to go.

I've used my rubber hockey pucks for all jacking operations including when the car has been put on a lift rack and I have no problems at all. Zero frame damage, not even a scratch. You can't even tell the pucks have ever been installed. Oh yeah, I remove my pucks after every use. I see no reason for pucks to stay in place all the time.

 

Thanks for all the input on this issue.

The original pictures I posted were of the passengers side location, and the drivers side is actually dented in even more (it's shoved in about 8mm). All of this damage occurred in less than 10 lifts of the vehicle at autocross events using the aluminum pucks.

I double checked my jack, and with the aluminum pucks in place it would not be possible for the jack to contact the frame.

My conclusions thus far:
- my aluminum pucks were probably designed with only commercial 4 post lifts in mind (the diameter of the aluminum pucks is small and aluminum can mess up your frames finish)
- it's probably best not to lift the entire side from one jacking location (especially not with the smaller aluminum pucks)


So in the future my puck use will be limited to 4 post lifts, and then it will only be the hockey puck (non-metallic) variety.

Another lesson learned the hard way, but I hope the damage is only cosmetic.

 

The four locations on the frame rails are used:

1. To support the car as it is being assembled at Bowling Green. Big arms on an overhead rail system support it simultaneously on these four points until it starts rolling on its own four wheels.

2. As tie-down points for shipping. A key is slipped into each slot and a strap puts a couple of hundred pounds of force into the frame to snug down the suspension, but not bottom it out.


The Chevy shop manual recommends that the car be jacked up on specific points on the massive aluminum crossmembers as shown in THIS FAQ THREAD.

 

Here is what it should look like ...

 

This is what I also use, either a 2x4 wood block or a cut piece of tire.

Warren

06 DSOM Vert,Z51,M6

 

You might want to check your rad for bird remains!

 

There is obviously a '#3', which is: to lift the car on a 4 point lift, as in to work on the car at the dealership or any other service shop.

I use 2x4 shaped to clear the rocker panel cutouts, but I have some slight frame deformation as the OP experienced. I have had 2 hockey pucks crumble/split on me, and I will never bet my rocker panels on them again!! Use caution guys, and always check those hockey pucks for splitting/ damage before you use 'em!

 

Ok, I understand.

However, I would think something had to be in contact with the area of the frame around the perimeter of the puck to dent it as shown in the pictures.

 

And if you are using 1 puck to lift the whole side of the vehicle you can multiply those values x2.

 

Looks like you've been running a fowl..

I always clean the feathers out from under my vette after bird season..

 

I snapped the 'it should look like' picture at a local car dealer, they had a used C6 convertible sitting on the lot. Guess the test drive involved running over local wildlife ... I didn't look to see what was stuck in the radiator!

"I would think something had to be in contact with the area of the frame around the perimeter of the puck to dent it as shown in the pictures"

One thing I noticed about the aluminum jacking pucks is that they can move quite a bit in the slots. From the scrapes in my paint it looks like the pucks moved as far as they could towards the outside of the car. Perhaps this may have allowed the jack to contact the frame, or somehow led to the frame denting.

 

I knew mine looked funny, I'm missing a feather...