Broken spring bolts
Thread Starter
Racer
Joined: Jul 2010
Posts: 261
Likes: 0
From: Manahawkin NJ
Broken spring bolts
Two of the four bolts that hold the spring to the differential were snapped off before I acquired my '74. I have seen the ears towards the back broken off, but on my car the front two snapped off flush.
Has anyone ever seen this before? I am wondering if the previous owner broke them when installing the spring or if they broke while driving.
Thanks
Tom
Has anyone ever seen this before? I am wondering if the previous owner broke them when installing the spring or if they broke while driving.
Thanks
Tom
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Could be he broke them off.. but more than likely a sign the rear spring was not installed properly.
The rear spring is to be installed snug when the car is elevated and only torqued down under the car weight! Failure to do this can result in broken ears and bolts.
Sometimes getting those bolts out can be a real PITA... Good luck.
Willcox
The rear spring is to be installed snug when the car is elevated and only torqued down under the car weight! Failure to do this can result in broken ears and bolts.
Sometimes getting those bolts out can be a real PITA... Good luck.
Willcox
Race Director
Joined: Feb 2006
Posts: 12,239
Likes: 19
From: Chino CA
Could be he broke them off.. but more than likely a sign the rear spring was not installed properly.
The rear spring is to be installed snug when the car is elevated and only torqued down under the car weight! Failure to do this can result in broken ears and bolts.
Sometimes getting those bolts out can be a real PITA... Good luck.
Willcox
The rear spring is to be installed snug when the car is elevated and only torqued down under the car weight! Failure to do this can result in broken ears and bolts.
Sometimes getting those bolts out can be a real PITA... Good luck.
Willcox
Thread Starter
Racer
Joined: Jul 2010
Posts: 261
Likes: 0
From: Manahawkin NJ
Melting Slicks
Joined: Oct 2006
Posts: 2,417
Likes: 336
From: Texas
i had one break on my 79, had to drill it and remove with an ez out, i replaced all 4 with grade 8 bolts, from napa, i used the method above to dearch the spring. two of the bolts,that are closest to the front need to have thicker washers because if too long a bolt is installed it will penetrate/crack into the rear cover, causing an oil leak.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
As long as you have the weight of the car on the spring when you torque it you'll be fine. The problem comes in to play when the rear spring is torqued before sprung...
Willcox
Thread Starter
Racer
Joined: Jul 2010
Posts: 261
Likes: 0
From: Manahawkin NJ
My luck will be that the bolts snapped when the bolts bottomed out. If this was the case, the bolt will be very difficult to remove with an easy out. I am going to remove the whole rear and swap it with a rebuilt one I have.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
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
Race Director
Joined: Feb 2006
Posts: 12,239
Likes: 19
From: Chino CA
EDIT: I'm done cleaning and painting....I'm putting it back together this weekend !!!!! Woo-Hoo !
Last edited by MrJlr; Sep 16, 2010 at 12:36 AM. Reason: add
Le Mans Master
Joined: Aug 2006
Posts: 7,421
Likes: 1,558
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Then install the spring to trailing arm bolts and lower your Vette on to the ramps and torque the 4 bolts under the differential.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Melting Slicks
Joined: Oct 2006
Posts: 2,417
Likes: 336
From: Texas
tom, i dont know how it broke, i noticed it while getting a new exhaust system installed.
i believe the original bolts were grade 5, thats why i went ahead and replaced all of them.
probably just fatique. it was the original spring and bolts. but who knows what previous bubba owners have done.!
i believe the original bolts were grade 5, thats why i went ahead and replaced all of them.
probably just fatique. it was the original spring and bolts. but who knows what previous bubba owners have done.!
