74 Leaf Spring Bushings
Thread Starter
Instructor
Joined: Dec 2020
Posts: 126
Likes: 27
From: Mesa, AZ
74 Leaf Spring Bushings
When I had my 74 SB up in the air doing rear brake work, I noticed the rubber leaf spring bushings have definitely seen better days. I did notice that when the car was jacked up, the bolt was not centered with the hole in the trailing arm where it would be removed from so I'm assuming the best was to do this is with the weight of the car on the suspension. The car does not have a rear sway bar and I have looked over various threads and believe I have a pretty good idea on how to tackle it safely. My two questions are;
1. Does replacing these bushings affect rear end alignment?
2. Since I'd like to keep the rear of the car sitting at the height it is at now, should I simply count the number of threads showing on the bolts before changing the bushings and then tighten back to similar position afterwards?
1. Does replacing these bushings affect rear end alignment?
2. Since I'd like to keep the rear of the car sitting at the height it is at now, should I simply count the number of threads showing on the bolts before changing the bushings and then tighten back to similar position afterwards?
Race Director
Joined: Nov 2006
Posts: 13,177
Likes: 7,781
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Question 1. No it does not affect alignment if ride height is returned.
Question 2. New rubber bushings will likely raise your car a tad. You may wish a couple fewer threads showing.
Question 2. New rubber bushings will likely raise your car a tad. You may wish a couple fewer threads showing.
Thread Starter
Instructor
Joined: Dec 2020
Posts: 126
Likes: 27
From: Mesa, AZ
Race Director
Joined: Nov 2006
Posts: 13,177
Likes: 7,781
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Yup, should be a cup like washer that is part of the spring.
been many, many years since I removed the factory steel spring. But even my VB&P Mono spring has cups that are a part of the spring.
When you buy a "Kit" That has the bolts, nuts, washers and rubber bushings. You don't get the ones on the spring. as they are part of the spring. Swagged on as it were.
Interesting problem. Perhaps someone else has better information for you.
Me, I'd lose that heavy, squeaky, bouncy spring in a heart beat for a mono spring.
been many, many years since I removed the factory steel spring. But even my VB&P Mono spring has cups that are a part of the spring.
When you buy a "Kit" That has the bolts, nuts, washers and rubber bushings. You don't get the ones on the spring. as they are part of the spring. Swagged on as it were.
Interesting problem. Perhaps someone else has better information for you.
Me, I'd lose that heavy, squeaky, bouncy spring in a heart beat for a mono spring.
Thread Starter
Instructor
Joined: Dec 2020
Posts: 126
Likes: 27
From: Mesa, AZ
Yup, should be a cup like washer that is part of the spring.
been many, many years since I removed the factory steel spring. But even my VB&P Mono spring has cups that are a part of the spring.
When you buy a "Kit" That has the bolts, nuts, washers and rubber bushings. You don't get the ones on the spring. as they are part of the spring. Swagged on as it were.
Interesting problem. Perhaps someone else has better information for you.
Me, I'd lose that heavy, squeaky, bouncy spring in a heart beat for a mono spring.
been many, many years since I removed the factory steel spring. But even my VB&P Mono spring has cups that are a part of the spring.
When you buy a "Kit" That has the bolts, nuts, washers and rubber bushings. You don't get the ones on the spring. as they are part of the spring. Swagged on as it were.
Interesting problem. Perhaps someone else has better information for you.
Me, I'd lose that heavy, squeaky, bouncy spring in a heart beat for a mono spring.
Only confusing part to me is why 4 cups are included when assembly manual only shows 1 per side. My biggest concern with replacing the spring with a mono is fear of it becoming ridiculously high. It's already at peak height (for my taste) in the rear and even with knowing I can go with 8 or 10" bolts to lower it, I still am concerned about opening a can of worms. But what do you say? Maybe you can talk me into it, lol!
Race Director
Joined: Nov 2006
Posts: 13,177
Likes: 7,781
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
VB&P Mono spring rear. 330 lb. Bilstien shocks, B8's rear.
Factory Gymkhana springs front. one coil cut sitting on a 3/8 inch spacer.
Rear hanger bolts, 7 inches long. Factory are 6 3/8th's
Never seen a kit with 4 cup washers before but clearly you proved me wrong.
Changed out my rear spring in the mid 90's. Best thing for ride and handling I ever did. But yes you need correct shocks to match.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,809
From: Cool Northern Michigan
PurePearl,
Been numerous stories on this forum about rear ride height complaints after installing so & so springs and / or cushion kits.
Worst case scenario, if you just can't stand the new ride ht. Take it back apart, one side at a time and shave the new rubber cushions a bit.
You know the ride ht with smashed cushions, you will know the ride ht with new cushions. So remove just enough material to get it perfect.
I don't like to see people using extra long spring bolts to reduce ride ht. This puts the castle nut closer to the tires sidewall. In the event that the tire starts losing pressure, the bolt will gladly remove the sidewall for you. Not pretty.
Use extreme caution when doing this type of work. The leaf spring is likely greasy right where you place your block of wood, C-clamp and jack.
If you have ramps, by all means back the car up on them for plenty of room underneath and knowing the car can not drop on you.
Been numerous stories on this forum about rear ride height complaints after installing so & so springs and / or cushion kits.
Worst case scenario, if you just can't stand the new ride ht. Take it back apart, one side at a time and shave the new rubber cushions a bit.
You know the ride ht with smashed cushions, you will know the ride ht with new cushions. So remove just enough material to get it perfect.
I don't like to see people using extra long spring bolts to reduce ride ht. This puts the castle nut closer to the tires sidewall. In the event that the tire starts losing pressure, the bolt will gladly remove the sidewall for you. Not pretty.
Use extreme caution when doing this type of work. The leaf spring is likely greasy right where you place your block of wood, C-clamp and jack.
If you have ramps, by all means back the car up on them for plenty of room underneath and knowing the car can not drop on you.
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
Race Director
Joined: May 2006
Posts: 18,692
Likes: 2,572
What about this? Exact same oem part numbers, according to my AIM. https://www.ebay.com/itm/175351924067
Only confusing part to me is why 4 cups are included when assembly manual only shows 1 per side. My biggest concern with replacing the spring with a mono is fear of it becoming ridiculously high. It's already at peak height (for my taste) in the rear and even with knowing I can go with 8 or 10" bolts to lower it, I still am concerned about opening a can of worms. But what do you say? Maybe you can talk me into it, lol!
Only confusing part to me is why 4 cups are included when assembly manual only shows 1 per side. My biggest concern with replacing the spring with a mono is fear of it becoming ridiculously high. It's already at peak height (for my taste) in the rear and even with knowing I can go with 8 or 10" bolts to lower it, I still am concerned about opening a can of worms. But what do you say? Maybe you can talk me into it, lol!
Intermediate
Joined: Apr 2022
Posts: 47
Likes: 16
From: Illinois
2022 C3 of the Year Finalist - Unmodified
Hi 4-vettes. When I was doing my shocks I too noticed the bushings on the leaf spring bolts were probably original to the car. When you say 'a tad' on height, do you think it might be 1/2" to 3/4" (12.7-19.05 mm)?