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Discussion Starter #1
The Roadmonster is getting a little saggy in the rear. Stick with GM? Get from Dal? Or are aftermarket springs any good?
Just looking to restore ride height to spec and don't want to buy junk.
 
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Discussion Starter #2
Go with OEM parts if they are still available.

Are you sure the springs on the car now are the problem?
 
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Discussion Starter #3
I'm pretty sure. 138K on the car and it is basically just the right rear that sags. Shocks are pretty new. Don't know what else it could be.
I'm just wanting a good deal on OEMs or comparable aftermarkets. Can't they be had for like 50 bucks a piece somewhere?
 
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Discussion Starter #4
What is the spring code--look at the SPIL on the trunk lid and look for the alpha-numeric codes that start with 8xx and 9xx. I can look up the PN and see, if available, what they cost.

Other option is to find the tag on one of the springs itself.
 
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Discussion Starter #5
i have a 95 caprice and called today as a matter of fact for new springs. i was told $60 each. but maybe different areas have different pricing.
 
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Discussion Starter #6
tonymo, was that a dealer or auto parts price?
 
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Discussion Starter #7
My right rear appeared to be sagging too. Some one on the board said it the top of the coils should be facing the drivers side. so i tried it and it changed it a bit but still not all better. Also this was evident with two sets of springs both Used SS Rears and Stock 9c1's I was wonder if this is not to due with the springs?
 
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Discussion Starter #8
After a few trips with the trunk loaded my 96SS started to sag in the rear. I installed the Air Lift bags and plumbed the valves seperately. Works well and cost was about $ 80.00 plus an easy install in my garage.
 
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Discussion Starter #9
Navy Lifer,
I looked at the label in the trunk. Man, there is a lot of numbers on that thing! OK, I think these are the numbers you are talking about:
8RZ
9RZ
Still wondering where I should go to get these springs. I tried using Dal's website to price some parts the other day and they seemed expensive as hell.....
Never bought anything from him before, but I always heard he was reasonable........
 
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Discussion Starter #10
94 Roadmaster : that website has the "bend me over" (i.e. GM retail) prices on it.

E-mail Dal ([email protected]) for some FAR better pricing ;)
 
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Discussion Starter #11
Was talking to some local motorheads today. They said the Moog parts are exact replacements for GM.

Is this true? Anybody got the correct Moog p/n for the RM? I'd like to order them for this weekend, but don't want to get the SS springs by mistake.
 
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Discussion Starter #12
The Moog parts will NOT be exact replacements.

E-mail Dal if you want exact replacement Roadmaster springs....
 
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Discussion Starter #13
The OE replacement for the RZ spring is 22076683. This spring is no longer listed in the parts price files. This spring is a "soft ride" (18.0 n/mm) spring rate, low load rate spring.

The other spring in the 18.0 n/mm category is 22076517, which covers spring codes RA/RB/RC. This is still a good number--these codes are for a spring with slightly higher load rate, but it should not affect ride height in any significant amount.

If you wanted to go to a higher spring rate (ride will be firmer), the 27.0 n/mm springs are:

22132374 HK (no longer available)
22076523 HJ, RK/RJ/RX higher load rate

Cost prices for the OE-spec springs are running $45 to $48 each--so you can get them from Dal, for example, for $50 to $53 each, plus shipping.

For reference, spring code HL is PN 22132375 and is the lowest rated spring on the 27.0 chart, and happens to be the spring spec'd for the Impala SS. It is a "special case" in that it was also designed to provide about 10mm lower ride height than any other spring in the inventory.

I realize spring rate and load rate can possibly be confusing, but "spring rate" is an engineer's spec for the vehicle's dynamic behavior target--18.0 n/mm being in the range of about 100# per inch of chassis compression. This rate is part of a package of specs to provide certain ride & drive characteristics in keeping with what the target customer would expect--in addition, tire specs, shock selection, body mounts, steering effort, seat design, etc, all contribute to the achievement of the goals set for the product.

For reference/comparison, in the case of the Impala SS, the rear spring rate and wheel rate is right around 150# per inch of chassis compression, and GM spec'd those springs at 27.0 n/mm--which are about 50% stiffer as compared to the 18.0 n/mm springs. Again, as a reference, wagons came with 37.0 n/mm rear springs--much stiffer, though in this case, a wagon has more weight on the rear when static & unloaded, so a higher rate spring is necessary to provide equivlent ride height specs and equivalent ride quality, and still be able to carry rated load.

A range of springs with varying load capacity can have the same rate of compression by design. What happens is that the number of turns of wire and the diameter of the wire are varied--so wire size alone does not tell you that a spring is stiffer or softer. Typically, larger wire diameter will increase the total load that the spring is capable of supporting, but depending on how the wire is wound can still make it behave as a "soft" (rate of compression) spring.

Ride height is a combination of factors that defines the spring specs--for a desired spring length at a given rate, the engineers & spring specialists have to work out just how tall the springs need to be so that when loaded the spring behaves as either a 18, 27, or 37 n/mm spring, provides the load capacity for the vehicle suspension specs, and provides the target ride height. A taller spring, unloaded, when compared to another PN for the same application, does not by itself tell you that the vehicle will sit higher when that particular spring is in place, so don't be fooled into thinking a taller spring will always raise the car.

The other option is Moog or other aftermarket sources, including ACDelco, but these are NOT "exactly the same" springs as the OE code-tagged springs. They are generic ball-park parts that will get you close, and probably fit a wide range of vehicles/years using the same chassis, where GM had much more specific specs year by year. Spring rates may not match those used in production applications, in other words. Can you tell the difference from the driver's seat(?)--maybe, maybe not.

Here are the springs listed for your vehicle in ACDelco & Moog equivalent. These springs are sold in pairs and are generally less expensive than the OE parts.


ACD PN GM PN
45H2007 88913677 standard Load 1060# Spring rate 124# cost +10% ~$42/pr
45H2022 88913692 HD Load 1211# Spring rate 173# cost +10% ~$78/pr
45H3011 88913772 variable (same as Moog Cargo Coil) cost +10% ~$48/pr

Moog
5245 standard Load 1060# Spring rate 133# (linear rate)
5419 HD Load 1211# Spring rate 173# (linear rate)
CC621 Cargo Coil Load 640# Spring rate 175# (starting rate)

Hope this helps!
 
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Discussion Starter #14
Being the car has "RZ" springs both left and right, may I suggest swapping them left to right to make sure before replacing them?
A soft sprung car is very susceptible to "outside forces" when it comes to ride height and the problem may not be your rear springs at all.
For example, have someone push down on your front bumper corner and watch. It takes very little to upset the rear.
If you swap left to right to check you might save your self the cost of a new set of springs that do nothing for your problem.
Regards, Gerry
 
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Discussion Starter #15
Bill, heck yeah that helps! That is just what I needed to know. Thanks a lot!!

Gerry, I hear what you are saying. Good idea, but with 138k on the springs, don't you think changing them would be a good idea anyhow? I don't know, maybe I'll try what you said. I also might just throw on a set of Moog 5245's that I found locally today for $72 for both. I sure hope it helps though. Be pretty pissed if afterwards that corner still sags. This car is treated very well and hasn't had any hard knocks. No big potholes that I can recall, no accidents. So hoping the springs do the trick......
 
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Discussion Starter #16
DANA/TRW Spring any good?

NAPA has one with the same 124# spring rate as the:
ACD PN GM PN
45H2007 88913677 standard Load

NAPA Chassis Parts Coil Spring - Rear
Item#: NCP2771889

Price: $ 54.99/pair
 
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Discussion Starter #17
Went down to NAPA today and ordered the DANA springs. The numbers on them are:
load: 1059# rate: 124#

These seem to be pretty close to the OEM springs.

FWIW, Dal says that he can get the originals under a diff pn, but he doesn't know the rates on them, since they haven't rated them like that for 10 years. He says that they are just rated "RZ" now. Price: $50.50 ea plus shipping. Twice the price of the DANAs, but a very good price for GM.

Will let you know how I like them.
 
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Discussion Starter #18
The DANA springs seem to be working out good. Slightly more ride height +5/8" A "little" firmer ride. At least compared to old stockers. I think I would recommend these. If anybody wants some the NAPA pn is: 277-1889

It didn't help the sagging passenger rear corner though. Both sides came up, so I'm still looking at 1-2" difference. It almost seems like it varies with how and where I park the car.

Unless someone has a better idea, I'm prob gonna cut the coil on the high side to try to level it.
 
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Discussion Starter #20
Thanks for the thread Jeff. I read it a couple times. Sounds like maybe I have LCA problems too.
Are the bushings hard to replace?

Last weekend I did a little measuring. With the axle supported: The distance on the spring mounts seems identical side to side, so I guess they are okay. They look fine. The length of the high side shock is a half inch more though. They are air shocks, but run from a T, so should be same pressure on each I think. Shock mounts appear normal.

Still nearly 2" higher measured to top of wheelwell on drivers side. Only 1" difference though if I measure at backup lights at rear bumper. Ain't that peculiar? Also as far as I can tell all the control arm bushings seem intact and look ok.

If I haven't bored everyone to death already with this topic, any comments or ideas would still be appreciated. I'm tempted to just live with it, but it really bugs me.
 
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