Hitman's Pontiac Trans Am Forum

Trans Am Information => Trans Am Tech => Suspension => Topic started by: Angelo on March 19, 2012, 03:01:41 PM

Title: Standard vs Heavy Duty Springs
Post by: Angelo on March 19, 2012, 03:01:41 PM
Can someone explain how the factory decided between using Standard vs Heavy Duty springs?

I was reading about the WS6 performance package and apparently they used the same springs as the regular Trans Am, so I'm starting to wonder if "Heavy Duty" was an option ordered by the customer for other reasons or did all Trans Am's in the late 70's get Heavy Duty springs?
Title: Re: Standard vs Heavy Duty Springs
Post by: joe d on March 19, 2012, 07:41:40 PM
most of the application catalogs ask if it has a/c or not, i recall seeing soem a/c application springs installed and the car was higher than normal, as for the leaf springs i am not sure if there is a difference
Title: Re: Standard vs Heavy Duty Springs
Post by: rpguitarrepair on April 10, 2012, 09:36:58 PM
I have been told by Dave at Touring Fbody that the WS6 rear leaf(s) were stiffer and rated higher/ lb load.
Title: Re: Standard vs Heavy Duty Springs
Post by: pats79455ta on May 02, 2012, 04:34:55 PM
how many actual leaf springs were in the ws6 , and what was the load
Title: Re: Standard vs Heavy Duty Springs
Post by: Greenbird76 on May 02, 2012, 04:51:43 PM
how many actual leaf springs were in the ws6 , and what was the load
4 leaf spring and rated at 126lbs/sq/in.  I have eatons version and I love them.  And TRW coils up front.
The Esprit originally came with the hD springs from the factory.  5 leaf and the car must of rode like a granny mobile.  It also had no rear sway bar and a wimpy 7/8 inch front bar.  now the car has the 1 3/16th WS6 bar with poly bushings.  My entire suspension is based off the Ws6 option.  Right now is only a ws7 due to the lack of rear disc brakes.  I have frame connecters ready to go and will order solid bushings. 
Here is decent pic of the Eaton spring installed.  ;D
(http://i1184.photobucket.com/albums/z340/greenbird76/P1010060.jpg)
Title: Re: Standard vs Heavy Duty Springs
Post by: pats79455ta on May 02, 2012, 04:55:16 PM
im at the point where im going replace them and ive heard anywhere from 5 to 6 leafs that went in the ws6, im also installing the poly bushing and the poly leaf spring pads
Title: Re: Standard vs Heavy Duty Springs
Post by: Greenbird76 on May 02, 2012, 05:02:43 PM
6 leaf would be a truck spring IMO.  Its what my 79 k5 had on it.  More leafs do not equal better response.  Arc of each leaf and quality of metal used in production and  do however.  And Eaton's are one of the best, it not the best aftermarket oem spring available.   
Title: Re: Standard vs Heavy Duty Springs
Post by: pats79455ta on May 02, 2012, 05:06:28 PM
great pic thx, i took out a 4 leaf set up, hmmmm i mite just keep them like that
Title: Re: Standard vs Heavy Duty Springs
Post by: Angelo on May 02, 2012, 05:16:22 PM
That rear suspension pictured looks really good!

I looked up the rear springs and from what I found all the Trans Am's in 79-81 had the same rear springs WS6 or not, though non-Trans Am's may have had something different. I don't think you can tell what a spring rate is just by counting the number of leafs. Eaton's web site has something that explains all the factors including thickness, diameter, etc...

If you knew the hassle with stock rear disc brakes and getting them adjusted you may be glad you have the rear drum. I have rear disc and I'm dreading the day I start working on them, which is going to be in the coming weeks. Do a search on this forum on the topic, you may be better off with one of those S10 or LS1 brake swaps, especially if you didn't plan on running an emergency brake.
Title: Re: Standard vs Heavy Duty Springs
Post by: Angelo on May 02, 2012, 05:23:09 PM
Maybe the WS6 rear spring is different, I just did a quick search and found this thread: http://www.78ta.com/HTAF/index.php?topic=17919.msg186647#msg186647
Quote
the WS6 used the 126# 4 leaf spring

Mine is a 4 leaf spring in the back, but is it the 126#, I don't know how to tell?
Title: Re: Standard vs Heavy Duty Springs
Post by: Greenbird76 on May 02, 2012, 06:46:18 PM
Drum brakes are ok.  I rebuilt everything- all new.  Check out my complete build thread here- http://www.allgentransams.com/TATA/index.php?topic=2327.0      I started converting to stainless lines, but did not finish.  I am aware of the number of leafs not signifiying a ws6 set up.  It is the spring rate.  Your #126 is quite interesting since the spring rate for ws6 is 126lb/sq/inch.  Start a thread on here asking guys with the origianl ws6  and ws7 packages to count there laefs.  I do not believe i have ever seen a pic of a 5 leaf ws6 car. 
Title: Re: Standard vs Heavy Duty Springs
Post by: Angelo on May 02, 2012, 07:06:40 PM
Just so I'm not confusing the convo, I have a regular (not WS6) 81 trans am all wheel disc car. The rear has 4 leaf, I just don't know what # they are and would love to know where to look to find out.

I got Moog 590's (HD for turbo 301 ws6 I believe) for the front, I'm worried now they may be bad for a 400 block, we'll find out in a month or so.