Door gap when put on jackstands
Thread Starter
Racer
Joined: Jan 2006
Posts: 256
Likes: 0
From: Norfolk VA
Door gap when put on jackstands
When I put my car on a lift or lift it up on jackstands, I notice the gap at the top of the door become greater. That's not suppossed to happen right? I usually put the jackstands right before the doors on the front, but this has me wondering. I don't see any obvious frame problems...
Racer
Joined: Dec 2007
Posts: 404
Likes: 2
From: Kingston Ontario
I had a similar and it was 1 of the front body mounts had rotted. When I had the body mount fixed it also fixed an array of other minor problems that I had not really noticed because everything has worstened so gradually
Melting Slicks
Joined: Dec 1999
Posts: 2,116
Likes: 156
From: Mid West
Cruise-In III Veteran
The frame is pretty flexible on these cars. Mine did that too, and the frame was in fine shape with just minor surface rust common to cars of this age.
After I welded some frame reinforcements along the sides, the car doesn't flex at all now when placed on jack stands.
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
The frame is pretty flexible on these cars. Mine did that too, and the frame was in fine shape with just minor surface rust common to cars of this age.
After I welded some frame reinforcements along the sides, the car doesn't flex at all now when placed on jack stands.
Pro
Joined: May 2007
Posts: 593
Likes: 0
From: Warrenville IL
These cars have some flex in them. I put my '75 on stands and the passenger door doesn't want to close anymore. Once I get it down it will be fine.
I've read several posts that reference people opening the doors and popping the hood before jacking up any C3 and they have had trouble once the car was on stands and had flexed.
I've read several posts that reference people opening the doors and popping the hood before jacking up any C3 and they have had trouble once the car was on stands and had flexed.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
These cars have some flex in them. I put my '75 on stands and the passenger door doesn't want to close anymore. Once I get it down it will be fine.
I've read several posts that reference people opening the doors and popping the hood before jacking up any C3 and they have had trouble once the car was on stands and had flexed.
I've read several posts that reference people opening the doors and popping the hood before jacking up any C3 and they have had trouble once the car was on stands and had flexed.
The frame is pretty flexible on these cars. Mine did that too, and the frame was in fine shape with just minor surface rust common to cars of this age.
After I welded some frame reinforcements along the sides, the car doesn't flex at all now when placed on jack stands.
Believe you're OK all you like...but the results won't be pretty when your car cracks in half on the highway.
Drifting
Joined: Jul 2004
Posts: 1,695
Likes: 65
From: Kissimmee fl
Finalist 2021 C3 of the Year - Modified
2017 C3 of Year Finalist
Cruise-In VIII Veteran
St. Jude Donor '07
They're flexing because the frames are weak. Jason, you just proved the point. A C3 frame SHOULDN'T flex when lifted, and one that does is a sign of problems. As I have said many times, my 77 has been on stands for 18 months and the doors still work just fine.
Believe you're OK all you like...but the results won't be pretty when your car cracks in half on the highway.
Believe you're OK all you like...but the results won't be pretty when your car cracks in half on the highway.
I have had mine jacked side to side, front to back, one side or the other or even one corner and never had a problem opening the doors or the hood.
Drifting
Joined: Mar 1999
Posts: 1,432
Likes: 22
From: Oxford CT
They're flexing because the frames are weak. Jason, you just proved the point. A C3 frame SHOULDN'T flex when lifted, and one that does is a sign of problems. As I have said many times, my 77 has been on stands for 18 months and the doors still work just fine.
Believe you're OK all you like...but the results won't be pretty when your car cracks in half on the highway.
Believe you're OK all you like...but the results won't be pretty when your car cracks in half on the highway.
Drifting
Joined: Oct 2007
Posts: 1,458
Likes: 1
From: Collinsville MS
St. Jude Donor '08
mine has been on stands for about a month now. Doors, hood and tops all close or open with no problems. If the jackstands were in the wrong positions on the frame, could that cause flex?
Thread Starter
Racer
Joined: Jan 2006
Posts: 256
Likes: 0
From: Norfolk VA
I looked at it today and there's no cracks in the frame anywhere. Unless there's major rust issues, metals don't really just soften. My body mounts are pretty bad, that was on the agenda to fix next. I'll replace them and look into getting frame supports welded in. I'll have to check the forum for posts on frame supports. Thanks guys.
Melting Slicks
Joined: Dec 1999
Posts: 2,116
Likes: 156
From: Mid West
Cruise-In III Veteran
They're flexing because the frames are weak. Jason, you just proved the point. A C3 frame SHOULDN'T flex when lifted, and one that does is a sign of problems. As I have said many times, my 77 has been on stands for 18 months and the doors still work just fine.
Believe you're OK all you like...but the results won't be pretty when your car cracks in half on the highway.
Believe you're OK all you like...but the results won't be pretty when your car cracks in half on the highway.
Racer
Joined: Dec 2007
Posts: 404
Likes: 2
From: Kingston Ontario
I looked at it today and there's no cracks in the frame anywhere. Unless there's major rust issues, metals don't really just soften. My body mounts are pretty bad, that was on the agenda to fix next. I'll replace them and look into getting frame supports welded in. I'll have to check the forum for posts on frame supports. Thanks guys.
Just my 2 cents worth
Racer
Joined: Dec 2007
Posts: 404
Likes: 2
From: Kingston Ontario
Sorry .One more thing when you do your body mounts stick with rubber . The poly's are to stiff and do not allow for body flex .Body mounts are intened to allow for flex because the frame should not .
Just my 3 cents worth
Just my 3 cents worth
Racer
Joined: Dec 2007
Posts: 404
Likes: 2
From: Kingston Ontario
Last edited by donnd; Dec 20, 2007 at 10:03 PM.
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
The only reason the factory used rubber mounts was for ride quality. 68-72 cars came with aluminum mounts, which are going to be a helluva lot more stiff than poly.
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
I looked at it today and there's no cracks in the frame anywhere. Unless there's major rust issues, metals don't really just soften. My body mounts are pretty bad, that was on the agenda to fix next. I'll replace them and look into getting frame supports welded in. I'll have to check the forum for posts on frame supports. Thanks guys.