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Discussion Starter · #1 · (Edited)
Or anyone that would know for that matter. Here is what I have, working on a B4U caprice and the owner found and wanted to replace the springs on the car with factory units. The rears looked fine and installed and it is sitting at the same height. The problem is I went to put in the front units and I took out the old and figured that there would be some sag, but the new springs have exactly one more coil on them, he purchased them from a friend of his that owns a shop, but I am not sure that he got the suspension code correct. The part number on the new units are 22076507 and code FTH or FTF, I can't remember right now. Is there anything that can cross reference this number, I found one website, but it doesn't give me any information on these units. I almost think that these have to be wrong, please help, thanks in advance.

This is all that I can find on that part number
http://www.gmpartsgiant.com/compone...suspension-front-mb063010106-lt1m301bl35.html
 

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Discussion Starter · #2 ·
Just looked on the passenger side it still has the data tag on it and it lists it as 22076513 with code FTN, but there is nothing listed for this either. I am stumped I am going to put the originals back in as I think that the 22076507 units are wrong.
 

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Mike,

It appears that your "client" has acquired incorrect springs.

Some background to understand production springs

In the FSM, in an easily-missed section (3) titled Steering, Suspension, Tires and Wheels, there is a chart/diagram (in my 96 FSM it's page 3-18) that provides Trim Height information for each vehicle suspension RPO.

B4U cars were equipped with the FE3 suspension, and all of the measurements are based on the springs that were spec'd for FE3, as listed on the SPIL (on the trunk lid) and the original tire size.

Referring back to the link above--background information--and with parts book information, I can tell you this:

FTH & FTF springs are 53 n/M spec--ie, NOT used on the FE3 suspension. On the OE spring chart, these springs are "mid-range" in the lower-rate chart (looking at 94-96 only).

The FTN spring, which you should find on the SPIL, listed as 6TN & 7TN, is a 77 n/M spring, again mid-range on the higher-rate chart.

The parts book chart does not provide specs as we can get from the Moog catalog--no turn counts, no wire diameter, no rate numbers other than as I've described (linked) above, which only refers to "highest load rate" down to "lowest load rate".
 

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Discussion Starter · #5 ·
Cool thanks fellas, I figured as much, I reinstalled the old spring and I will let him know. What is funny is the part number That is listed on the factory spring on the passenger side, I can't find reference to anywhere. I did see the chart in the manual as it is listed under all of the stuff for the pinion angle and what not, thanks again for everything.
 

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Discussion Starter · #6 ·
You need to check out the B-Body manual, there is quite a few differant spring variations used. Depending on the options a computer may have choosen which spring to use.

http://www.impalassforum.com/vBulletin/showthread.php?t=246201&highlight=manual
Wolf's site isn't working, I have tried to download the manual before but wasn't able to get it, it stalled out. I will try again and see what I find. FYI it is a tow pack, B4U car with FE3 suspension as Bill stated.
 

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Mike, can you post (or PM to me) the VIN or look on the trunk label for the front spring codes (6xx & 7xx)?

There's no mystery here, in reality.

The service (replacement) springs often merge PN's--on the production line, there are more springs to choose from. As a service part, some of the springs (with different codes) are so similar that it makes no sense to keep all of them available as service parts--what matters is replacement in pairs, since a new spring, if only ONE is defective, may not be an exact match, and if only one is replaced, it may not match up correctly (ie. trim height) with a used spring, even if the spring codes may match.

The production FTN spring used on this B4U car had a PN of 22076513. The service spring that meets FTN specs had a PN of 22076512. That is not to say that ALL B4U's used this specific spring--that is why the production line has so many choices, but, for certain, B4U's all used springs from the higher-rate group.

The "softer" FTH production PN was 22076506, FTF was production PN 22076507, but for service purposes, the 2 springs were merged to PN 22076507.
 

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Mike, can you post (or PM to me) the VIN or look on the trunk label for the front spring codes (6xx & 7xx)?

There's no mystery here, in reality.

The service (replacement) springs often merge PN's--on the production line, there are more springs to choose from. As a service part, some of the springs (with different codes) are so similar that it makes no sense to keep all of them available as service parts--what matters is replacement in pairs, since a new spring, if only ONE is defective, may not be an exact match, and if only one is replaced, it may not match up correctly (ie. trim height) with a used spring, even if the spring codes may match.

The production FTN spring used on this B4U car had a PN of 22076513. The service spring that meets FTN specs had a PN of 22076512. That is not to say that ALL B4U's used this specific spring--that is why the production line has so many choices, but, for certain, B4U's all used springs from the higher-rate group.

The "softer" FTH production PN was 22076506, FTF was production PN 22076507, but for service purposes, the 2 springs were merged to PN 22076507.
And now we learn why GM went bankraupt!
 

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To confuse things a bit further, some cars end up with different springs side-to-side in production--a function of placement of weight based on the RPO list.

If "perfection" is to be achieved in a service situation (somewhat moot for an out-of-production vehicle with significantly limited OE replacement parts availability), replacing springs in pairs would be further compounded by the need to find 2 different springs, rather than a pair with the same PN. But, I'll also wager that cars with 2 different springs in front or rear most likely have a common replacement--the 2 different springs would be merged to one in the parts book.

I doubt this could be considered a "GM fails" situation, as I'll bet that all domestic manufacturers do something similar, and doing so actually reduces inventory & operating costs...the problems GM has had to deal with go well beyond any issues surrounding replacement parts.
 

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Yep--as I had suggested possibly having different springs on each side.

6TS - left front - production PN 22076512
7TN - right front - production PN 22076513

The service PN for both of these springs is 22076512--no stock is showing at Vintage Parts, so it will be a matter of finding a dealer that may happen to have one or a pair still on the shelf....I can check on this tomorrow.

The TN spring is one position higher on the GM spring chart (in the parts book), meaning it has a slightly higher load rate.
 

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The service PN for both of these springs is 22076512--no stock is showing at Vintage Parts, so it will be a matter of finding a dealer that may happen to have one or a pair still on the shelf....
The well is dry--there are ZERO assets of this spring anywhere.

Have your client contact Eaton Detroit Spring if he really wants an exact replacement. There are quite a few reasonable alternatives, however.
 

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Wolf's site isn't working, I have tried to download the manual before but wasn't able to get it, it stalled out. I will try again and see what I find. FYI it is a tow pack, B4U car with FE3 suspension as Bill stated.
i moved all my stuff over to a new datacenter so soon my friend soon :)

DNS population takes the longest.
 

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Discussion Starter · #20 ·
Hey Bill wanted to ask you one more thing, or well a couple anyway :) Called Eaton Detroit Spring, and they have the springs in stock to a point, the only thing that they could go off of was year make and model and whether it had air or not, and whether it needed to be heavy duty. The rating on the ones that he gave me a quote on was 2900 lbs rating for the front pair, 419 lbs per inch The rears where 1059 lbs rating for the pair at 123 lbs per inch.

What are your thoughts on this, I did ask the gentleman how it would compare to the original and he said most likely it would be the same, but GM did there coil rating's differently.

Any thoughts that you may have would be great thanks again for your help.
 
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