Hey all,

25 years ago, I did a nut and bolt resto on my 76 4-speed L-48. My father and law has had her locked away in the garage for sunshine cruises and weekly washings during this time. The only things that he needed me to "fix" over the years were the calipers a few times, a carb swap last summer and removal of the Lake Pipes for a stock setup.

Several months ago, I rebuilt the front calipers again and noticed that the urethane bushings for the end links had completely **** the bed.....basically, reverted back to powder....so I replaced them at the same time.

John never got a chance to drive the car again.....so it has been sitting since I did that.

Last weekend, I went to his house to finish clearing it out and retrieve the Vette. Basically, she fired right up and I drove her onto the trailer. Few hours later, I backed her off the trailer and into the garage at home.

Today, my son and I took the Vette for a cruise. Mediocre acceleration shifts the *** over hard, and in the opposite direction under deceleration. Great! All poly bushings in the *** must be returning to dust as well.

Upon returning home....hastily....I backed her in with the wheel turned and the left front tire rubbed the wheel arch. A quick peek through the wheel well opening and down from above showed all of the fronts have failed as well.

Few questions after that unnecessarily long "around the mountain" intro.....

Has anyone ever experienced the complete disintegration of Polyurethane bushings? To wit.....like an old bakelite Snap-On screwdriver handle that sweats....then eventually turns to dust? (showing my age here)

I chose Poly when I did the restoration to "firm" up the suspension....and it worked wonders.....but now......I don't want to redo everything in poly just to have this happen again. Does it naturally degrade like rubber just at an accelerated rate? Yes I did say 25 yrs ago, but all of the poly stuff on my 70 1/2 Z28 is fine as rain after 20.....and it actually has gotten use. The vette has under 5k miles in the last 25 yrs, albeit from regular use, but mostly out of the garage for a ride around the block, a wash, and back into the garage.

I will never "compete" with this car. Does the cost to move to tubular A-Arms justify their existence? Sure....way easier to replace bushing when needed, but.....

What about coil over? Does it make sense for a cruiser?

In the back, I went with aftermarket adjustable camber rods when I rebuilt the leaf pack and did all of the bushings on the trailing arms. That job really sucked, and I don't look forward to round two. What better long term.....coil-over or composite mono leaf?

I know.....lot's of questions....can't wait for your input!

 

If your happy with the condition of the springs ,ride height is good , then why change anything ? Unfortunately you got the poly stuff that was poor quality and needs to be replaced. Why not just go back to new rubber and it should be good for another 20 years or so. That's what I would do .

Yes there have been guys on here that have had there low mileage poly bushes crumble to dust just sitting in a shed . Your not the first to experience it .

 

Wow bazza....that's really informative. I had no idea that poly was so unstable.

Ok....sounds good......I will go rubber in the front unless someone can tell me a reliable poly source with good pieces...

In the back, there is a 2" sag. For me, unacceptable. Looks like one of those dumb *** trucks with a lift kit on the front only....although it does help with weight transfer.....but I'm not having it. It's been 25 yrs since I was purchasing parts for this car, so I am certain material quality has gone up....or is that another dumb assumption?

 

I put new rubber bushings on the ends of the rear spring when rebuilding my entire rear suspension. In 5 years time the new rubber bushings crumbled. They were purchased from a major Corvette vendor. They just don't make things like they used to. I run energy suspension bushings in my front A arms and all my sway bar links. But rubber in the forward rear trailing arms. These need to twist as well as pivot, so I believe rubber is a better choice there. Bottom line, nothing lasts forever. 25 years is a long time.

 

O.K.....so yes. Dumb assumption. All of mine came from Eckerds....(spelled on purpose)...easy for me cause they are close.

Thanks for the lead....I'll check out Energy Suspension on the fronts. As for the rear, I also appreciate what you offer about the advantage of rubber. As far as the spring....it's just tired. 44 years and a complete rebuild 25yrs ago tells me those springs are sprung....so I'm relatively set on mono or coil-over. What are the pro/cons?

 

Just use the OEM rubber and it will out last you.

 

THere was a lot of old threads on the old poly stuff disintergrating but I think the new formula has solved that. As for the composite springs. They are more forgiving than the metal springs, thats why the later factory cars have composite. I have the VBP composites front and rear which I really like. If I had it to do again I would go to dual valve coil overs. I have bilstien shocks all around and they are great. They work great around town on most roads, worked great at the road course track and have zero issues. Personally I would do full poly, get what you can afford for springs and shocks but remember that most new springs may have to be cut to give you the proper height in the front. This is where I would do coil overs at a minimum. I the rear may need more in the way of lateral support than just swapping to a coil over

 

Rear spring. Composite mono spring. Bilstien shocks. Front springs. Mine are still good after 44 years. But 550 lb springs seem to be the most common choice
as per the factory rubber advice. Good luck finding "Factory" rubber.

 

There was a bad batch of poly bushings floating around when your car was last restored. Not your fault. I have every confidence that modern manufacturers have solved this issue, and I used Energy Suspension poly bushings everywhere when I replaced every bushing in my 80 (except the trailing arms, which are rubber, and the heim-jointed strut rods).

Coil-overs let you tune the ride height. For a street car, that matters in the front. In the rear, a composite bar is likely sufficient. Be sure to get a low-arch spring, if you intend to keep the 15" wheels.