Rear Leaf Spring, 1990 Convertible

[OLDCHEV]

While checking out a nail in one of my rear tires, I noticed that the rear spring was shattered on the drivers side! I got her up on jackstands and removed the spring and I also found stress cracks on the passenger side. This car is equipped with the soft ride suspension, not the performance setup.

I have a complete C-4 suspension that I was going to use for another project and compared both springs. The one I took out had more arch but, was .200" thinner than my project spring.

I had to remove one of the upper spring mount shims (pretty close to .200" thick) on the third member to allow the thicker spring to seat so I would not crack the mount plates.

The spring I took out had no markings, the one I put in had a metal plate glued to it marked "BMF-011747".

I am not concerned with the ride quality if it changes but, am very concerned about the camber of the rear tires changing.

Cannot put the car back down on the ground until I get the nail removed and both tires rebalanced (tomorrow).

Anyone messed with their rear suspension that might have comments or suggestions if I am on the right track?


Thanks

 

[Hib Halverson]

The spring codes BMF is not the correct spring for a 90. It's a considerably higher rate (nearlyh double, in fact), hence the extra thickness.

Using that spring on the rear will not only cause a decease in ride quality but it will also cause the car's balance to shift towards oversteer. Be careful driving the car at high speeds entering turns. With the rear end stiff and the front soft, she's going to want to swap ends on you when you don't expect it.

 

[OLDCHEV]

Thank you for the quick response!

I was afraid this spring was too stiff as the rest of the suspension it was attached to seemed to be very high performance. Everything on it is adjustable and the rear ratio seems to be about 3.73. This is my wife's daily driver and I do not want to put her in a bad situation.

I normally buy my parts from Mid-America. Any other suggestions on where and what to buy?


Thanks

Don

 

[OLDCHEV]

Maybe better yet, what can I do to the front suspension to match the rear?

My wife might need a new Daily driver!

 

[redc4corvette]

With the new spring you should notice about a 2 inch lift at the rear and with the weak shocks in the front the car at high speed will bounce from side to side.
To get it by I would lower the tire presure in the rear to about 25 lbs or so ,this car is going to bounce around alot.:booty

 

[OLDCHEV]

Just got a "STOCK" replacement spring from Mid-America. It is marked and their catalog lists it as rear spring, 84-96.

It looks identical to the one everyone recommended not to use. The factory tag reads VBP, 84-96R, sport.

What do you think?


Thanks

 

[WhalePirot]

I noticed that the rear spring was shattered on the drivers side! I also found stress cracks on the passenger side.

I have a photo of my '84 rear leaf that cracked and allowed the car to
'low ride'. NOT cool!