Rear Suspension Question
Thread Starter
8th Gear
Joined: Nov 2024
Posts: 8
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Rear Suspension Question
The rear end shimmys around when I let off the throttle. Car is low mileage but obviously very old. The differential or more likely the hubs have apparently moved around enough that the factory leaf spring clamps are missing. Some goon put hose clamps on them….. which remarkably are somewhat holding but the stack of leaves has shifted at each distal end for sure. The biscuits and rubber components do appear worn, obviously I need a new spring. Is there a specific spot to start with in terms of what to replace first? Or is this just “rebuild the rear suspension” scenario?
Melting Slicks
Joined: Nov 2006
Posts: 3,411
Likes: 1,821
From: Apple Valley, MN
[QUOTE Or is this just “rebuild the rear suspension” scenario?[/QUOTE]
Short answer - yup.
Every rubber bushing needs to be replaced, period. Mileage makes no real difference when you’re dealing with 45 year old rubber.
Check the end play on the differential axles and consider replacing the rear wheel bearings.
Short answer - yup.
Every rubber bushing needs to be replaced, period. Mileage makes no real difference when you’re dealing with 45 year old rubber.
Check the end play on the differential axles and consider replacing the rear wheel bearings.
Race Director
Joined: May 2006
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You shouldn't need any clamps on the spring if the bolts on the center bracket were properly torqued and the separators haven't worn.
Unless the spring is showing signs of sagging buy the separators and rebuild the spring. Do not fully torque the 4 bolts in the center until the full weight of the car is on the spring.
Unless the spring is showing signs of sagging buy the separators and rebuild the spring. Do not fully torque the 4 bolts in the center until the full weight of the car is on the spring.
Thread Starter
8th Gear
Joined: Nov 2024
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Replies: Rear Suspension Questiom
Guys, thanks for your help. I can figure out how to check that end play on the axles during the pending deconstruction. My goal is to leave those axles in those hubs and avoid playing with those again. I think the suspension can be done with hubs on the axles. I like the idea of rebuilding the spring as a cheaper option. I saw those parts are available at Corvette Central. I think the spring separators are missing currently or I can’t see them. Good comment on spring bolt carriage too yet the spring itself doesn’t seem like my wobble, I bet it lo. Sounds like a piece at a time is not the right solution and I need to just pull it all out.
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,987
From: Connecticut, USA
1978 inner axles, if original, were bad from day one. Regardless of low mileage, if you leave them in place you will be back at it in the future. Now, if you catch it in time and know what to look for, those axles may very well be saved but need treatment.
That is what I would do and I do this every day.
That is what I would do and I do this every day.
Melting Slicks
Joined: Aug 2016
Posts: 2,346
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From: CLEVELAND STUCK IN OHIO
2024 C3 of the Year Finalist- Modified
Yea,, I believe its time to do it all. If you plan to drive the car out of your driveway, ya better get all that done ASAP. You won't regret doing it.
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Thread Starter
8th Gear
Joined: Nov 2024
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Rear Suspension Question -continued
You shouldn't need any clamps on the spring if the bolts on the center bracket were properly torqued and the separators haven't worn.
Unless the spring is showing signs of sagging buy the separators and rebuild the spring. Do not fully torque the 4 bolts in the center until the full weight of the car is on the spring.
Unless the spring is showing signs of sagging buy the separators and rebuild the spring. Do not fully torque the 4 bolts in the center until the full weight of the car is on the spring.
Is my vette stock?? HAHA
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
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Mine did that when my strut rods were loose...check those bushings as well
Old Pro Solo Guy
Joined: Dec 2017
Posts: 8,094
Likes: 4,447
From: Marlton NJ
The strut rod bushings handle 90% of the cornering load, and seem to be the first IRS part to wear out.
When T/A arm bushings dry rot, they crumble under the twisting, the rear end tends to shift around when you let off the gas, and steer the car.
OTOH the crossmember bushings are a much harder rubber, there is no rotation /movement involved, and even very old ones still seem to be OK.
And they are a real pain to get out. I would inspect those once apart and then decide.
The T/A bushings you can inspect on the car, use a large crowbar, and pry in the TA pocket. The arm should not move. At all. It can move 1/2" when bad.
Same with the strut rods. Inners and outers.
The inner axle stubs check their movement on the car with a dial or digital caliper. Check the wheel bearings with a dial indicator.
Thread Starter
8th Gear
Joined: Nov 2024
Posts: 8
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Rear Suspension Question
It’s definitely in curves and when I vary the throttle, let-off usually, that rear end moves and feels unpredictable. I was just into the axle stubs and they were tight.
QUOTE=leigh1322;1608695878]
The strut rod bushings handle 90% of the cornering load, and seem to be the first IRS part to wear out.
When T/A arm bushings dry rot, they crumble under the twisting, the rear end tends to shift around when you let off the gas, and steer the car.
OTOH the crossmember bushings are a much harder rubber, there is no rotation /movement involved, and even very old ones still seem to be OK.
And they are a real pain to get out. I would inspect those once apart and then decide.
The T/A bushings you can inspect on the car, use a large crowbar, and pry in the TA pocket. The arm should not move. At all. It can move 1/2" when bad.
Same with the strut rods. Inners and outers.
The inner axle stubs check their movement on the car with a dial or digital caliper. Check the wheel bearings with a dial indicator.[/QUOTE]
ns
QUOTE=leigh1322;1608695878]
The strut rod bushings handle 90% of the cornering load, and seem to be the first IRS part to wear out.
When T/A arm bushings dry rot, they crumble under the twisting, the rear end tends to shift around when you let off the gas, and steer the car.
OTOH the crossmember bushings are a much harder rubber, there is no rotation /movement involved, and even very old ones still seem to be OK.
And they are a real pain to get out. I would inspect those once apart and then decide.
The T/A bushings you can inspect on the car, use a large crowbar, and pry in the TA pocket. The arm should not move. At all. It can move 1/2" when bad.
Same with the strut rods. Inners and outers.
The inner axle stubs check their movement on the car with a dial or digital caliper. Check the wheel bearings with a dial indicator.[/QUOTE]
ns
Is my vette stock?? HAHA
Joined: Oct 2015
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2020 C3 of the Year Finalist - Modified
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Check the bushings in the struts.......make sure the bolts are tight
Old Pro Solo Guy
Joined: Dec 2017
Posts: 8,094
Likes: 4,447
From: Marlton NJ
To check either strut rod bushings or trailing arm bushings you can try two ways.
Look in the narrow gap to see the rubber and see if any cracks, crumbs, deterioration, etc.
Stick the end of a crowbar in there, and try to pry them both sideways and vertical. They should barely move ~1mm. When they are bad, they move a lot.
Look in the narrow gap to see the rubber and see if any cracks, crumbs, deterioration, etc.
Stick the end of a crowbar in there, and try to pry them both sideways and vertical. They should barely move ~1mm. When they are bad, they move a lot.