Determining the correct 5-leaf springs - 69 SS 396

[Jonesy]

Here's a spring calculator:

http://www.chevynova.org/69_12437_L3...78_Springs.htm

Springs were selected based on the weight of the options on the car.

[Fhakya]

Jonesy: That is a cool calculator..new to me.

After punching in a couple of different configurations it occured to me that there had to be 'ranges' available to the line workers. My logic being that there wasn't a spring custom built for every car. There had to be some quick way for the production worker to know things like A/C + 396 = XXX spring etc etc..

Anyone know how that took place in the production setting?

[Hotrodpaul]

My 69 Camaro L-78 had YP front springs and 5 leaf BK code rear springs.

Paul

[rpoz11]

Wasnt the 4-leaf and 5-leafs in 69 factory predetermined?
Not aware of different rated 4-leafs & 5-leafs that year...

[Hotrodpaul]

Small blocks such as Z-28's and SS's etc usually had 4 leaves, where big blocks had 5 leaves. I guess it depended on the type of suspension and options ordered.

Paul

[70 ls6 convert]

69 z28s used 4 lief springs,69 ss used 5 lief, and heavy duty front if you orderd a big block,

[bertfam]

Kris,

That's not quite right. Taken from the "Ask CRG Archives" (question #121):

[ QUOTE ]
121. Is there any difference in ride or handling between the 4 or 5-leaf springs? Why did GM put the 4-leaf springs on Z28 instead of 5-leaf springs? Is there a difference in ride height?
Dave McBride, 18-Jun-1999

[This was asked on the Camaro Institute (CI) and answered by us there. Since CI has no archive and we felt this question was important to others, we repeat it here.]


1. There was not a five-leaf spring. There is an entire family of five-leaf spring designs (in 1968-69, only monoleafs were used in 1967). The family covers different spring rates, arch heights, and different maximum load design points. Springs were selected to create an equivalent vehicle position or stance in the loaded condition, depending on the gross weight of the vehicle. The one exception was the G31 spring series, which, as Heavy-Duty (HD) springs, were specifically designed with a higher arch and a higher unloaded ride, allowing them to deflect more on loading - resulting in a higher loading capacity. The G31 springs purposely cause a vehicle to sit up higher in the back until it is loaded with extra weight. However improper vehicle stance will also occur if the wrong spring is installed.

2. The (1968-69) Z28 was not limited to the four-leaf spring, nor was a (1968-69) non-Z28 prohibited from having a four-leaf spring. We have documented five-leaf Z28s and documented 4-leaf non-Z28s in our data, and the factory spring tables confirm that this was intentional. In particular, the F41 option on the 1968 L30/M20 resulted in the four-leaf spring being applied to a non-Z28. The 4-leaf spring was lighter but also with reduced resistance to wind-up and decreased damping. If the weight of options so warranted it, the Z28 was equipped with certain five-leaf springs.
A detailed CRG Research Report is in preparation but it is coming along slowly due to the enormous amount of time required to do it right, and due to competing needs from other projects and from the CRG web site.

[/ QUOTE ]

Ed

[Nova Research Project]

[ QUOTE ]
There had to be some quick way for the production worker to know things like A/C + 396 = XXX spring etc etc..

Anyone know how that took place in the production setting?


[/ QUOTE ]

Yes, the total weight of the car was calculated based on the options purchased. The computer selected the spring needed to handle the weight and printed a 2 letter code on the Chassis Broadcast sheet. The assembly line worker looked at the sheet and grabbed the corresponding spring from the rack. The Assembly line worker did not have time to calculate just grab and go.

Greg R.