I'm re-posting, and re wording this question from my last thread:
I find when I put my IROC up on jack stands using the sub-frames for the support. I find that if I put up all 4 at max. height all but the passenger front side will sit level. I have to use a different taller jack stand to balance it out. Does this mean my sub-frames are bent/twisted. When the car is on all 4 tires it does not appear to sag, and it looks straight. The doors close well also when on all 4 tires. But the doors do sag when the IROC is up on the jackstands. I actually have to lift the doors up a little to close them on the jack stands.

 

Yes, your frame is bent and the car is worthless - I'll give ya $500 for it!

Seriously - may not be a big issue. My car does the same - seems like there's always one corner not sitting on the stands the same as the other 3. Maybe it's in the location your jacking at - my driveway isn't exactly flat or level and I always attributed this to the driveway. I'd expect the doors to not shut the same when on stands as they would when on all four wheels - weight distribution is definitely going to be different. There's also alot of difference between teetering on four little stand supports vs. stable sitting on 4 big tires. If you don't have excessive tire wear that can't be taken care of with a good alignment, I wouldn't worry about it. Besides - who ever said that GM produced every frame perfectly straight? I'm sure no car has every left the factory with a perfect frame, unless it was by accident.

But - the $500 offer still stands

 

Well what your encountering is most likely the reason why people view sub frame connectors as an absolute must for these cars. The unit body construction has a lot of flex in it and when its not resting on its wheels as the factory intended it to be and designed it to be the forces may cause it to flex in ways to cause the issues described. Long story short i believe thats normal however its easy to check to see how strait the body really is. If you by chance have a factory manual they have all the points to measure from and to and what they should measure.

 

Agreed.

As far as the door issue, that's expected. The doors play a huge role in the structural integrity of the uni-body. As Camaronewbie said, you're changing it's characteristics.

My 2nd gen was VERY bad... I remember reading on a 2nd gen forum not to open the doors if the jack stands were too far out on the back and front, lol... (I'm sure it would have been fine).

 

Ouchh!!! man that really hurts.
My tire wear is pretty good all the way around, other than the baldness on the rears due to excessive road testing LOL.
This makes alot of sense, and I do put the jack stands at the farthest points from each other. I hope I'm not causing any damage by doing that as I've done that many times.

The subframes are also bolt on's which I forgot to mention, I do plan on welding them on soon though sometime this Winter/Spring.
With that being said is there any special/certain way they should be welded in since there is so much flex. Like should the car be in the air supported by the subframes, or should it be on all 4 the tires etc?

 

It really should be on all 4 tires on level ground so the chassy is as it wants to sit naturally. I would either do it on ramps or spot weld them in place while its on the ground and then lift it to have better access to do the real welding.

 

Thanks for the info.

 

If you have access to welding equipment but no lift, I figured out a cheap way to get the car high enough to get under and get the sub frame connectors (and anything else underneath you may want to change easily) Go rent a uhaul car trailer. It should cost about $60 for 24 hours, but is sooo worth it. The silver trailers have a split deck design, so there is plenty of room to get in between the wheels and do serious work under the car.

 

Wow!
Thanks for the tip, but is that the same height as using jack stands?

 

its actually taller....but you have to be a little thin to squeeze under there....my fat a$$ cant do it

 

Do that. My car doesn't sit perfectly on jackstands either... in the middle bay of the garage. The height of my garage floor is off by almost 3/8 of an inch in places, so of course it won't always sit right on jackstands.

 

this is just my car.. 2 weeks after getting from the dealer.about 60 miles on th OD. i had
SSM's weld in SFC. and the lift bars installed. before it was shipped off the Lingenfelters..

to this day. it will sit on 3 jack stands and the doors close with your finger tip.. the open corner of the car with out jackstand sits just under 1/4" Hi
above the rest.. the sfc are installed with the car on a drive on rack
ment to do front end work.. could be the way GM made the cars
could be one frame rail sits hi or low by 1/4 "