Frame/A Arm failure
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
BeeJay... Danny and Chris can fix this for you.... they just finished a $60K baja build for Daric Colman of the Seattle SeaHawks.. Full custom race suspension.
and they can make it much stronger as well...
and they can make it much stronger as well...
Burning Brakes
Joined: Jun 2005
Posts: 1,129
Likes: 106
From: laingsburg MI
2020 C3 of the Year Finalist - Modified
My 73 A-arm attachment looked similiar- spooked me to think of the potential failure. After viewing the "quality" of the GM factory welds, I had no reservations about welding it my self at home! I fortified the frame with the Power Manual recommendations too
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Norval talked about this years back and had some pics of his mods to strengthen this area.
You may still be able to do a search and find the threads, if your lucky he will still have the pics hosted.
Neal
You may still be able to do a search and find the threads, if your lucky he will still have the pics hosted.
Neal
Pro
Joined: Aug 2010
Posts: 698
Likes: 8
From: Stockholm Sweden
There is some pictures of those Corvette Racing Manual reinforcements added to my frame in my "garage".
https://www.corvetteforum.com/g/album/1302411
In addition one should complete (weld 100%) the pointwelds holding the front crossmember topside to the bottom side (clearly seen in the first post in this thread.
There is a LOT of force on the trailingarms when braking hard during inspired driving. Especially when one have big brakes and sticky tires..
https://www.corvetteforum.com/g/album/1302411
In addition one should complete (weld 100%) the pointwelds holding the front crossmember topside to the bottom side (clearly seen in the first post in this thread.
There is a LOT of force on the trailingarms when braking hard during inspired driving. Especially when one have big brakes and sticky tires..
Last edited by RickyBerg; Oct 6, 2014 at 10:56 PM.
Pro
Joined: Jan 2010
Posts: 533
Likes: 18
From: Boca Raton Florida
Is it time for a new frame? To do the repairs I think you'll need to have the body out of the way and probably the engine/transmission out as well. If you had a new frame from someplace like Collier with C4/5/6 suspension points you could have aluminum suspension components, rack & pinion steering etc. You could have the rolling chassis ready to swap in a long weekend. Think of the weight savings -- all those aluminum parts and a really lightweight wallet. Just a thought...
Army Hoist Operator
Joined: Feb 2009
Posts: 836
Likes: 17
From: OK
Bee Jay,
I intend to run in an autoccross for the first time in my '78. It's modified similar to yours. In which class do you run? I' guessing my car fits in SSM. I will be under the car this weekend inspecting the frame!
I intend to run in an autoccross for the first time in my '78. It's modified similar to yours. In which class do you run? I' guessing my car fits in SSM. I will be under the car this weekend inspecting the frame!
Safety Car
Joined: May 2004
Posts: 4,341
Likes: 1,568
From: los altos hills california
Did you happen to tighten the lower control arm bushings when the front end was suspended in the air instead of with the front end loaded down on the ground after settling in?
If you had tightened the lower bushing while the front end was suspended in the air you would have imputed a preload on the bushings for when the car was lowered and if the lower control arm bumpers are missing then you could really over turn the bushing on compression travel?
If you had tightened the lower bushing while the front end was suspended in the air you would have imputed a preload on the bushings for when the car was lowered and if the lower control arm bumpers are missing then you could really over turn the bushing on compression travel?
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Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,444
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I don't think that you could put enough shims to bring the alignment back
My 79 cracked the frame near the rear lower a-arm rear crossbar bolt on the same passenger side as yours. I caught it early when I had it up on a lift getting ready to do a front end alignment. I attributed my problem to 700# front springs and 295 width front road racing slicks, and poly a-arm bushings. With all that TQ the frame gave up. Yours has probably been cracked for quite some time and it kept getting bigger until you had catastrophic failure
I was able to weld, fish plate, and gusset the area on both sides.
A body shop with a framing machine could probably pull it all back into place and then cut out the bad and make it stronger than the original. Or compare it price wise of going to that recent post of the super tube frame setup
My 79 cracked the frame near the rear lower a-arm rear crossbar bolt on the same passenger side as yours. I caught it early when I had it up on a lift getting ready to do a front end alignment. I attributed my problem to 700# front springs and 295 width front road racing slicks, and poly a-arm bushings. With all that TQ the frame gave up. Yours has probably been cracked for quite some time and it kept getting bigger until you had catastrophic failure
I was able to weld, fish plate, and gusset the area on both sides.
A body shop with a framing machine could probably pull it all back into place and then cut out the bad and make it stronger than the original. Or compare it price wise of going to that recent post of the super tube frame setup
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
I have heard/read that the later shark frames were lighter/thinner steel than the early ones....and my pro welder buddy could fix that fairly easy right there in his garage, complete with added gussets and more welding....I just looked at my '72 frame which has had the cross support on it for years now, and it looks fine, I have '89 vette wheels/50 series tires on it and drive quickly, but it's all street driving, hardly a track car.....
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi
I got told that this brace will eliminate such cracks, but now stand corrected ! The brace eliminatse front crossmember bending during driving. It bends a lot because it is not straight.
May be it was already cracked when the brace was installed ?
Rgds. Günther
just a question, do you have a brace running between the upper control arms?
May be it was already cracked when the brace was installed ?
Rgds. Günther
Instructor
Joined: Jul 2008
Posts: 123
Likes: 0
From: Wertheim Baden-Württemberg Germany
Le Mans Master
Joined: Oct 2010
Posts: 6,903
Likes: 834
From: melbourne florida
2023 C3 of the Year Finalist - Modified
Pro
Joined: Aug 2010
Posts: 698
Likes: 8
From: Stockholm Sweden
Pro
Joined: Aug 2010
Posts: 698
Likes: 8
From: Stockholm Sweden
The recommendations below are (in my opinion) the least one should do to the frame before adding a HP Engine, HP brakes and wide sticky tires.
To me it is not surprising that a 40 year old production car made to cruise the streets on those tires of the era suddenly decides to give in after been driven hard on a race track.
To me it is not surprising that a 40 year old production car made to cruise the streets on those tires of the era suddenly decides to give in after been driven hard on a race track.