Somewhat comprehensive aftermarket rear spring guide

[KevinVarnes]

I have been sifting through reams of information trying to sort out all of the rear spring options for these cars. I've mostly been looking at them from a wagon perspective, but a lot of this applies to the sedans and coupes as well. Basically there are about 5000 different rear spring options for these cars. My goal is to try to condense all of the groups of springs into this list with cross references between manufacturers. Some of these springs are discontinued and may no longer be available. I have found that even if a spring is discontinued by one supplier there are usually other suppliers that still make the same part under a different part number. For instance I can go down to my local O'Reilly tomorrow and get the equivalent of the CC823 or CC821 if I wanted to. The 8797 appears to be the only one that I can only find NOS and no longer sold new. Strangely I believe Precision is owned by Moog which has discontinued a lot of these springs, but for some reason they sell them under the Precision name? I could only find the Precision springs listed at O'Reilly. They may be available elsewhere. I've also seen the Moog CC springs sold under other brands probably going back to the 80's on that though.

The best I can tell the 8797 is the same as the OEM rear wagon springs for the 83-86 LTD/Marquis. The 8599 appears to be the same as the OEM rear spring for the Fairmont/Zephyr wagons. It was also apparently used on the T-Bird and Cougar. I think the 8597 is the OEM equivalent to the sedan rear spring for F/Z and LTD/Marquis. Obviously the LTD LX is not included in this. I don't know what those received stock from the factory. This list only applies to stock style replacement springs. If you want to try aftermarket performance springs from a Mustang let us know how they work, but I use my wagon to haul my family and all of our crap for vacations so it needs to have decent load carrying capacity.

If you find more part numbers or errors, let me know and I will edit this post to try to keep everything together.

Here goes.

Moog CC823
Mevotech SMS823V
Precision Coil Spring SP08138 (O'Reilly Auto Parts)
Centric 630.65038
Lesjofors 4427536 (they list wire diameter at .657")

Free height: 12.63”
Installed height: 10.25”
Spring wire diameter: .6875"
Load to compress from free to installed height: 808lbs
Spring rate: 340lbs per in. (variable rate)
- these are the wagon "cargo coil" aftermarket heavy duty option


Moog CC821
Mevotech SMS821V
AC-Delco 45H3017
Precision Coil Spring SP08136 (O'Reilly Auto Parts)
Centric 630.61036
Lesjofors 4427535 (they list wire diameter at .610")

Free height: 12.29”
Installed height: 9.25”
Spring wire diameter: .625"
Load to compress from free to installed height: 804lbs
Spring rate: 275lbs per in. (variable rate)
- these are the sedan "cargo coil" aftermarket heavy duty option


Moog 8797
AC-Delco 45H2082
Duralast RCS8797S

Free height: 13.25”
Installed height: 10.25”
Spring wire diameter: .590"
Load to compress from free to installed height: 850lbs
Spring rate: 266lbs per in. (constant rate)


Moog 8599
AC-Delco 45H2040
Centric 630.65037
Lesjofors 4427507

Free height: 13.33”
Installed height: 9.5”
Spring wire diameter: .590"
Load to compress from free to installed height: 926lbs
Spring rate: 249lbs per in. (constant rate)


Moog 8597
AC-Delco 45H2041
Centric 630.61037
Precision Coil Spring SP08648 (O'Reilly Auto Parts)

Free height: 12.75”
Installed height: 9.5”
Spring wire diameter: .560"
Load to compress from free to installed height: 726lbs
Spring rate: 224lbs per in. (constant rate)