sprinter

I would like to know what are the differences between the rear springs on the auto and manual transmission 2001-2004 vettes.

The reason I ask is that someone gave me a Z51 rear spring off an automatic car (part No. 22146646) and I want to know if it fits on my M6 2001 vette.

Dan_the_C5_Man

Yes it will fit.

No difference between automatic and manual that I am aware of.

:cheers:

HalfMoon

Not sure what the differences are, but there are differences.

The part number he listed is in fact listed as for an Automatic, the part number for a Manual trans is 22179020.

??

sprinter

It seems from LS1howto.com that there is no difference... just wanted to know for sure before I pulled the springs off and checked the old fashioned way.

powderski13

The FE-1 springs are rated @439.66lb. front, @576.70lb. rear manual tranny, @588.12lb. rear auto tranny. The FE-3 springs are @525.31lb. front, @633.80lb. manual tranny, and @645.22lb. auto tranny. I installed used Z51 manual transmission springs on my AT vert.

Paras

How do these spring rates compare to coil spring rates? My front coil overs are 375 and back are 450

sprinter

"The FE-1 springs are rated @439.66lb. front, @576.70lb. rear manual tranny, @588.12lb. rear auto tranny. The FE-3 springs are @525.31lb. front, @633.80lb. manual tranny, and @645.22lb. auto tranny. I installed used Z51 manual transmission springs on my AT vert."

Does this mean that there are not any physical size differences and I will be able to install the A4 rear spring with no fitment issues?

You say the A4 rear spring can hold a higher load, does this mean that the A4 spring is stiffer than the M6 spring? ...and therefore would be the preferred rear Z51 spring.

HalfMoon

It looks as though the A4 spring is stiffer, to accomodate the weight of the A4 trans. This doesn't mean it's most preferred for a stick car. They pick spring rates to compliment each other, as a matched pair.

Saying that, I doubt the small difference will make much of a difference, other than probably riding a bit harsher than a factory Z51.

sprinter

Thanks guys for your help. I mainly post over on LS1Tech but you guys here are definately the Vette experts!

Dan_the_C5_Man

Thanks for the education on the spring rate differences.. I guess I should have looked it up in my factory manuals! :smash:

sprinter

I will buy the Z06 sway bar kit to complete the upgrade. I was very lucky to get my grubby little hands on these "factory sample" sway bars (a Z06 front and the Z51 A4 rear) ...for free mind you! :yesnod:

I still have to get the engine back together first... installing ported/valves/springs LS6 heads, CC224 cam and Kooks headers.