i put the cutlass up on jackstands tonight and now i cant open the doors. the gap between the doors and fenders are no more. why the heck did this happen? is this a bad sign of a weak frame?

 

Where do you have the jackstands placed?
They should be behind the front wheels and in front of the rear wheels.

The gaps will change because all cars flex some but the doors should open if it's jacked up in the right places and the panel gaps are set right. I worked at several gas station back in the day and was always the frame lift pad/arm placement guy, never had one fall or drive off the drive-on lift. You try not to open the doors if you don't have to when the car is on jackstands or a frame lift but I can't remember any car that you couldn't open the door on after it was up in the air? Convertibles doors could get tight at the quarter gap area, they can do that if you park them on uneven enough ground even with the boxed frames. The legendary Vista Cruiser has a boxed frame and a roof so it hardly even flexes when you jack it up.

 

I've heard not to open the doors on Corvettes when they are jacked up because of the risk of expensive body damage due to flex.

 

That's were I have them.

 

[QUOTE=STAYBG;156412]Okay, but they should be under the *frame*, not the *body*. If that is where you have them, then your body *and* frame are very weak and that is probably due to metal corrosion (rust).

 

Very common, chassis in the front is flexing down. Happens to mine when I put it on a two post lift. Once you put it on the ground it will go back. JKaz

 

I haven't lifted my 70 conv w/ a 2 post lift in years. I almost puked @ what happens to the side gaps when lifted from the center frame "box". Thankfully I have a drive on lift, or will put front wheels on ramps(chocked w/ something) & then lift the rear by the pumpkin & safety jacks under the frame. Hardtops aren't nearly as bad but still bow some.

 

Just make sure you are on the lift points as outlined in the Chassis manual, even then frame flex will be evident. Helps also to support the engine cradle. I put a jack under with a block and jack it up about a 1/4"
for support and leave it as long as the car is on stands. This will eliminate the frame drop mentioned in an earlier post.

 

thanks for all the replies. sounds almost common then.. so i wont worry to much about it i guess.

 

ok i fiured out why the doors wont open. the rear bottom part of the fenders are rusted and not securley bolts down so they move more with the front end when i let the jack down.

 

So, out of curiosity, why would placing jack stands at the rear axle tubes be a bad idea over the Chassis manual indicated lift points?

 

I bought new BFG tires for my '72 Cutlass several months ago that have been sitting in my enclosed garage until I get in gear to take the old tires off and have the wheels either painted or powder coated. Today, when I was searching for posts on the proper placement of jack stands, I came across these posts that made me concerned about potential problems with placing my car on jackstands. I would be using a 2-ton hydraulic floor jack and placing the car on jack stands in my garage. Any tips for properly putting the car on jack stands if I attempt to do it myself? Or should I try to find a car repair or tire shop that will remove the tires and leave the car on their lift while I get the wheels painted and then get the new tires installed? I plan to also remove and paint or powdercoat several parts under the hood (alternator & A/C parts, air cleaner, etc.) and the rear drums.

 

Well, this is just my own opinion, and others may hold opposing views, but these cars were flexible flyers from day 1 compared to modern computer-designed, crash-tested cars.

They bend all over the place all the time, and, in general, bend right back afterward.

You don't want to abuse their frames, but you can jack them up darn near anywhere, see some pretty big deflections (just watch how far the weight of the motor pulls the nose down if you jack from the "right" place on the frame behind the front wheel), and have them return right back when you let them down.

Personally, I prefer to jack them under the "ham" (differential), or by suspension points, like under the spring attachment areas on the rear axle shafts, or under the middle of the frame under the engine.

I wouldn't worry much, though - the car's probably been through worse.

- Eric

 

If it's for storage I would never put my car on stands. If garage fires don't scare you (you can't push a car out of a garage if it's on stands) then put the stands under the rear axle and front end so the suspension doesn't hang. I wouldn't put then on the frame. For a repair is one thing, but for months of sitting, bad idea IMO. Exposed stretched shocks can rust and when you let the car down months later, the seals can be damaged by the rust. My $.02

 

Good point.

 

In an evacuation, aren't you supposed to leave all belongings behind?

 

Only the ones you don't really care about. Wouldn't you want the chance at least. What's the idea about jacking the car up anyway? So it looks cool, so air gets to dry the undercarriage, because the suspension cannot take the car sitting on it? If it's to prevent flat spots on the tires, six months won't do it, or get old tires and put them on. I've been putting my car away every winter since 1987 and I don't get flat spots. So, it must be another reason.

 

It seems a little excessive to me for a hardtop. I did notice our 65 Biscayne rear 1/4 buckles just behind the drivers door at the track when leaving the line. It has a rock solid frame and body shell but does pull the tires off the ground a little. The frame relies on the integrety of the floor to add additional strength, you may have some issues as mentioned by Kurt..

 

I've only had that problem when working with convertibles.
The body panels do play a part in the rigidity of the car.If they are off,or rusted to the point where the main fastening points are not effective,that could add more flex to the frame.

 

Staybg,

Yes, on a car with rusted fender bottoms, you will get more flex than normal. I think your fine.

2 spots you can try to put the jacks:

1. Under the frame as far forward as possible before or behind the front wheels, or
2. right under the sway bar attaching point on the frame ahead of the front wheels.

#2 worked fine for me. If neither of those work, you have problems.