body sag
Thread Starter
Instructor
Joined: Aug 2005
Posts: 112
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From: Toronto Ontario
body sag
i have a friend with a 69 vert.he has already replaced his rear leaf spring assy with an oem unit.the spring did not correct the issue.his car sags on the left rear side about 3/4 of an inch.i know others have had discussions on this issue on the forum.any help suggestions would be great.can adjustments be made at the connecting links?
thanks,
chris.
thanks,
chris.
Le Mans Master
Joined: Nov 2004
Posts: 6,128
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From: North Alabama
chris...I am convinced this is a flaw in GM's mold and carried over through atleast 1973 on the C3's. You can jack the rear up with your left rear spring bolt but it will force the right front down and you will have different gaps from "tire top to fender lip" on all four corners...but...this is just mho
Thread Starter
Instructor
Joined: Aug 2005
Posts: 112
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From: Toronto Ontario
I will relay the information to my freind.he's going to come by for me to see the car and i will look at all those items for myself.the downside is its going to stress me out to see his car in great shape when mine is in a million peices right now.if i could figure it out he will be really happy.
The ORIGINAL and bestest
Joined: Oct 2000
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From: Toronto Ontario
Toronto Events Coordinator
My 72 has this exact same problem, exactly 3/4". This is very common in early C3's, and I also believe it is because of a flaw in the GM molds. I did a body off restoration on my car, and I can assure you there is no reason for this except how the body has been molded together.
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Le Mans Master
Joined: Jan 2000
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From: New Hill NC
You should determine if it is body related or suspension related. To do this, jack it up on the center box of the frame. Measure from the slots in the side of the frame to the floor and level the frame. Then look at and measure the body points to the floor. Measure the front and rear frame mounts to the floor. All of these measurements should be relative close side to side. This eliminates the suspension from the equation. If these measurements are close, but the car still leans, you have a suspension problem.
Racer
Joined: Jun 2005
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My 70 does the same thing, a little low on the left rear, and I turned the rear leaf with no luck, but I am having the front end rebuilt this next month while I am in Mexico (scuba diving and Corona drinking!) 
will put my results here after I return 
will put my results here after I return
Team Owner
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SPARTAN
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Where are you measuring? The only way to determine if the car is actually sitting lower on one side is to measure the suspension and not the body.
Le Mans Master
Joined: Aug 2000
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From: Austin TX
How does the NCRS judging guide deal with this?
If it is a GM body mold issue, no points should be deducted.
My 71 AIM does not distinguish side to side indicating that the General thought the molds were equal side to side.
If it is a GM body mold issue, no points should be deducted.
My 71 AIM does not distinguish side to side indicating that the General thought the molds were equal side to side.
Team Owner
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SPARTAN
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I can point out a very popular car that was built as recently as 1996 that was 'the same' on both sides according to the design. Reality was something entirely different.
Thinking they were equal, and knowing they're supposed to be equal are 2 different things
Thinking they were equal, and knowing they're supposed to be equal are 2 different things
Le Mans Master
Joined: Oct 2001
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From: Wildwood IL
Originally Posted by Code Blu
This might sound crazy but, you might want to also check your body mounts. I have seen some that are totally gone and it has effected the body. Just a thought.
Eddie
The ORIGINAL and bestest
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From: Toronto Ontario
Toronto Events Coordinator
Originally Posted by Silvr77
Not crazy at all...#4 solid body mount and reinforcment rusted out causing sag on my car. Replaced both sides and she's level side to side within 1/16"
Eddie
Eddie
Le Mans Master
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From: North Alabama
Originally Posted by 7t2vette
I did a body off restoration on my car. My car sat lower on the drivers side before the resto, so I chalked it up to the fact that the solid aluminum body mounts had turned into pretty much dust. Fast forward to body drop and shimming, and it soon became apparent to me that it was not the suspension or frame, it was how the body was bonded together. I could not shim away the problem because the amount of shims required to correct it, made the brackets for the rear bumpers go out of their normal range of adjustment. I thought I was going crazy, so I checked the space in the rear wheel wells that was between the bottom of the underbody, and the top of the rear frame rails, and it was the same on both sides, and the drivers side was still 3/4" lower! I ended up correcting it by using longer rear spring bolts to lower the passenger side to match. I have seen this problem on many early C3's....maybe they were the cars made on Mondays and Fridays!
very common problem
Safety Car
Joined: Oct 2000
Posts: 3,547
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From: Carbondale Pa.
Hey, I had the same problem with a '66 Convertible that I once owned, it sagged on the left rear corner,,, measured it here and there and found out it was the right front being slightly higher that dipped the rear . Previous frame damage maybe,,,,,,,dunno, adjusted here and there and lived with it. Maybe not entirely a C-3 thing. Peace,,,Craig 