Rear leaf spring

[bbrown41]

Hello,
I see the codes are different for leaf springs for different year C4's. Will an 88 spring fit on a 94, they do have different codes.

Thanks

 

[vetteoz]

Will an 88 spring fit on a 94

Yes

they do have different codes.

Depends on what application the spring was from
Perf suspension springs are rated different to base springs and accordingly have different codes

 

[bbrown41]

My car is a 94 it has a RHZ spring for 94-96 base, and the one I am looking at is a NYR 85 base(?) 86-93 base, 89-90 w. FX3&Z51, 90-91 w. ZR1. The one that I have now has a splinter or chip of about an 1/8 inch on the front edge of the driver side.

 

[bbrown41]

There are two springs available. One from an 88 base and the other from a 96. I am told that either will work on my base 94, but that the 96 looks different, more rounded from the center to the ends. Which would be the best for me, and would all of the rest of my existing hardware work with either? I'm new to this, and appreciate your help.
Bob

 

[boomdriver]

There are two springs available. One from an 88 base and the other from a 96. I am told that either will work on my base 94, but that the 96 looks different, more rounded from the center to the ends. Which would be the best for me, and would all of the rest of my existing hardware work with either? I'm new to this, and appreciate your help.
Bob

The codes are meaningless without understanding what they represent.

Find the C4 suspension chart here, and take note of the spring weights, speeds on the various suspension packages.

I think the one you;re considering is waaaaaaaaaaayyyyyyyyyyyyyyyyyyyyy too stiff to even compare.

The arc of the spring is a clue to the softness. More arc, more travel, more softness. The flatter the spring,. the stiffer/firmer/harder.

Consider this carefuly....you;re riding around right now on a 230lb/in gentle spring....the 85 spring you are asking about is right at 2 times stiffer.

"base" was 230-320 lbs with the Z51 at near 500 lbs/in. What was 'base' in 84 at 499lbs/inch was later made Z-51 performance as base went softer and softer in response to consumer complaints....
--------> "I can't drive my world class sports car down a gravel road and drink my coffee..."
Have a little cheese with your wine, Sir.

If you;ve never riden in a buckboard wagon...heres your chance.

Get the chart with the codes, weights and suspension codes so you can make an informed decision without regret.

 

[vetteoz]

There are two springs available. One from an 88 base and the other from a 96.
Which would be the best for me,

Bear in mind the C4 suspension was softened up in the later years to the point where the late "perf" suspension was softer that previous base suspension
The stiffer early spring would be a nice handling upgrade if that was what you were after but would need to matched to the correct front spring so as to maintain the factory setup

Base rear spring rate in '94 was 39 N/mm spring ; same as '85 - '93 base but 94 FX3 and most '96 had 26 N/mm rear

NB; the only rear spring listed to span '94- '96 is the softer 26N/mm unit

 

[bbrown41]

After looking at the table, it appears the 88 spring will work.
According to the table the rate for the 88 and the 94 are both 39.9 for the rear spring rate and 25.7 for the wheel rate. Thanks for all the help.
Bob

 

[boomdriver]

After looking at the table, it appears the 88 spring will work.
According to the table the rate for the 88 and the 94 are both 39.9 for the rear spring rate and 25.7 for the wheel rate. Thanks for all the help.
Bob

Actually, the yrs, rates and all that can be misleading...the real replacement value comes in the codes...I have a table somewhere. If I can find that, I'll post it for you. That tells you what code to look for and when used with the rates table, you know exactly what works and what you want to stay away from.

Trust me when I tell you, That those hard/fast springs have a place, but it ain't on the street!

ask me how I know...

 

[boomdriver]

Here is the simple list of rear spring data. The number after the code is the lbs per inch rate. 499 is very hard...148 is very soft.



Code #/in N/mm Year(s) GM part # GM Service Parts Catalog
---- ---- ------- ------- -------- ------------------------
BMH 499 [87.5] 1984 14045786 . . . . . . . . . . 7-H19


BMF 411 [72.0] 1984 14045785 . . . . . . . . . . 7-H19

NYU 326 [57.2] 1985-95 14080196 . . . . . . . . . . 7-H19 7-H22 7-I3

NYR 228 [39.9] 1985-93 22112253 . . . . . . . . . . 7-H19 7-H22 7-I3

RCA 228 [39.9] 1986-96 14106787 . . . . . . . . . . 7-H19 7-H22 7-I4

RHY 188 [33.0] 1992-96 17999322 . . . . . . . . . . 7-I4

RHZ 148 [26.0] 1994-96 22112253 . . . . . . . . . . 7-I4

___?d 148 [26.0] 1994-95 22112254 conv FE1 (SR) FX3 . 7-I3 no 3 letter code

 

[boomdriver]

Front spring data. Many more than I thought...:eyerole

Not all yrs interchange....later yr C4 had changes in steering geometry that effected the springs physical dimensions or length and how it fit into the lower control arm. The variations were not nearly as wide as the rears were. Here, fronts varied by 30 or 40 lbs...rears went between 200 to 500.



* FRONT (18 springs - HMP is listed twice because internet data gave 2 N/mm rates)

Code #/in N/mm Year(s) GM part # GM Service Parts Catalog
---- ---- ------- ------- -------- ------------------------
FHB 590 [115.5] 1988-91 10048553 . . . . . . . . . . 7-E9 7-E13 7-E19

BMB 521 [102.0] 1984 14045782 . . . . . . . . . . - not in microfiche

AA 491 [96.2] 1990-91 17988598 . . . . . . . . . . 7-E13 7-E19

FHA 476 [93.1] 1988-91 10048552 coupe FX3 FE7 + L98 7-E9 7-E13 7-E19

FHC 476 [93.1] 1988-91 10048574 conv FE1 (SR) . . 7-E9 7-E1347-E19

FSK 460 [90.1] 1992-95 17997091 . . . . . . . . . . 7-E19

FSM 385 [75.4] 1992-95 17997093 . . . . . . . . . . 7-E19

HMZ?a 379 [66.5] 1986-87 14106617 coupe FE7 ___ . . - not in microfiche

FSR 374 [73.2] 1992-95 17999031 conv FE1 (SR) . . 7-E19

FSS 374 [73.2] 1992-96 17999032 coupe FE1 (SR) . . 7-E19 7-E20

HMP 362 [63.5] 1984-87 14106617 . . . . . . . . . . 7-E5

HMP 379 [66.5] 1984-87 14106617 . . . . . . . . . . 7-E5

HA 306 [60.0] 1989-95 22145203 coupe FE1 (SR) FX3 7-E13 7-E20

JA 306 [60.0] 1994-95 22145227 conv FE1 (SR) FX3 7-E19

...?b 306 [60.0] 1995 22173029 conv FX3 (ER) . . 7-E19 no 3 letter code
...?c 306 [60.0] 1996 22173028 coupe FE1 (SR) . . 7-E19 no 3 letter code

HMN 278 [54.4] 1986-87 14094457 conv FE1 (SR) . . -

HKX 276 [54.0] 1985 14094458 . . . . . . . . . . page 7-C24 microfiche

HMP 261 [51.8] 1986-87 14094458 . . . . . . . . . .

 

[bbrown41]

Thanks for all the info. The first one the RHZ is what I currently have and the one below it is available, they both have the same GM Part # but different lbs per inch rate, so if I were to order by part # what would I end up with? Or would the 80 lb difference even be noticeable? Sorry to be so thick headed on this, I just want to keep a comfortable and safe ride.

Thanks

RHZ 148 [26.0] 1994-96 22112253 . . . . . . . . . . 7-I4
NYR 228 [39.9] 1985-93 22112253 . . . . . . . . . . 7-H19 7-H22 7-I3

 

[Hib Halverson]

Hey "Boomdriver"...where'd you get all that info on springs?

 

[boomdriver]

Hey "Boomdriver"...where'd you get all that info on springs?

uhhhhhh....


from YOU I think. Quite a few yrs ago.
I've had this for many years.

It was posted here at some time in the past but was deleted for some reason. I've found it to be extremely helpful over the years...

Thats only a small portion of the page....the rest is microsoft XP (graph/charted text) and will not copy & paste...
I'll have to scan the page in as a jpeg, then paste that..as soon as my useless ep-sonabitch printer decides to give up some ink...

 

[boomdriver]

Thanks for all the info. The first one the RHZ is what I currently have and the one below it is available, they both have the same GM Part # but different lbs per inch rate, so if I were to order by part # what would I end up with? Or would the 80 lb difference even be noticeable? Sorry to be so thick headed on this, I just want to keep a comfortable and safe ride.

Thanks

RHZ 148 [26.0] 1994-96 22112253 . . . . . . . . . . 7-I4
NYR 228 [39.9] 1985-93 22112253 . . . . . . . . . . 7-H19 7-H22 7-I3

I'm assuming the RHZ was D/C and replaced with the NYR
(very common spring) for that suspension package due to the 148lbs per inch being extremely soft, even with select ride suspension & shocks.

The stiffer/faster the spring rate the better the car will handle, at the sacrifice of comfort. The 200 into 300 lbs are fine for street cars IMO. Track cars or the hardcore enthusiast might enjoy the stiffer 400+ lb springs...as I did when it was 2 hrs a month...:eyerole