Factory Spring Part Numbers & Associated Lift

[l008com]

This is just the info I've been looking for!!! My truck is nice but even after adding new tires and bilstein HDs, the ride is still way to soft for me! But of course my codes are not on the chart. And that site people keep referencing to look up codes, makes you pay to look up codes. Does anyone know what spring #s go with these codes, 6RT and 7RS?

Also, is this whole thread only about front springs? What about the rears?

[navigator]

I think the rear springs are all the same.

[l008com]

Code: Select all

Front:
Spring# Rate(N/mm)  Check Load(N)   Length(mm)  Label Color
81      50          6820            418.8       Lavender
82      53          7240            417.0       Dark Green
83      56          7578            415.7       Gray
84      60          7934            412.6       Pink
85      63          8307            412.2       Light Blue
86      67          8646            409.6       Orange
87      70          8988            408.3       Dark Blue
88      74          9331            406.8       Light Green
89      77          9674            405.5       Tan


Code: Select all

Rear:
Spring# Rate(N/mm)  Check Load(N)  Length(mm)
YUZ     29.4        3720           422.5
YND     31.6        3833           421
YNF     33.9        4186           420
YHH     34.4        3953           410
YNH     36.2        4439           419
YHK     36.8        4186           409
YNJ     38.5        4692           418
YHL     39.3        4439           409
YNK     40.6        4945           418
YHM     41.9        4692           409
YJU     42.7        5199           418


Years back in this thread, someone posted a list of front AND REAR spring options. Can anyone verify that the rear spring list is correct? And if so, is there a way to match those up to the actual part numbers? The three digit codes look like RPO codes but as we know, there are about a million RPO codes for each part number. I re-ordered the 'rear' list by spring rate to match the 'front' list. I'm thinking of going from my 83/84 fronts to either an 87 or 88 in the front. I'd like to step my rear stiffness up a few as well to match.

[l008com]

*pingggggggg* I'm still trying to find part numbers for rear springs, very unsuccessfully. If anyone can help, please let me know. Thanks!

[Rickalicka18]

If you're thinking of going with 87/88 in the front, why not upgrade the rear to the tahoe z71 rear springs and shocks?

The front will lift around 1" With 87/88 and the back with z71 tahoe springs and shocks will lift the back about an 1.5". Also since you already have bilsteins hds, you could get the tahoe bilstein hds for the rear to keep the shocks all bilstein.

I have 87s in the front on mine and the z71 in the back with bilstein hds all around (tahoe bilsteins hds in the back) and I love the ride. Now I also have the 3" lift, with flipped UCAs, 265/70/17s, and my tires are spaced out about 2" from stock.

[HawkeyeC25]

Here's what I am able to get... these show the recent part numbers for the RPO. I was not able to find spring rate data for any of these, so not sure how useful it is. Also, there are 2-3 part numbers that were superseded by these recent numbers... so there might be other numbers floating out there for the rear springs.

[l008com]

I can google those part numbers and see if I can get more info on them. Or I could just assume the top is the softest and the bottom is the hardest, and pick about the same % down the list that I'm doing on the front, thus getting a stiffer spring. But who knows what I'd actually be getting so I'll see if I can find more info first.

Also I don't want to get new springs for the rear, that will need new shocks, when I already have new shocks. And I don't need a 1.5" lift in the rear. The ride height is fine, I'm more concerned about the ride quality.

[l008com]

After (way too) many hours searching, I haven't been able to find any details at all on the following rear spring numbers:

15948005
15948006
15948007
15948008
15948009
15948010
15948011

I can find them all in stock online. And having the dealer look up my VIN, I know my truck has the 010 rear. But that's all I can figure out. I thought I had at least determined that the 009 was for an EXT but I can't even confirm where I thought I read that. At least an EXT rear spring should give me some amount of increase stiffness.

I would think that the higher numbers would be stuffer. Especially since the higher numbers are more expensive. But it doesn't make sense to me that my truck would come with real soft front springs, and real firm rears, especially since I have the 5.3 which I assume is heavier than the i6? I suppose I could go down to a local parts department and see fi they'd let me see one of each spring, so I can compare the thickness and at least figure out which direction is stiffer/softer.

[l008com]

I found where I was able to look up the 009 spring as being for the EXT. Then, for completeness, I looked up the rear spring for a non-EXT LT and it gave me the same 009 rear spring. So as far as rear springs, I'm back where I started. Maybe I'll buy a 011 and a 007 and whichever is thicker, gets installed.

I did see two sets of moog rear springs elsewhere that were listed as EXT and non EXT, and the EXT did have a thicker rod diameter. So I dunno, maybe I'll get a set of those for the rear and cross my fingers.

[Trail X]

I originally was able to find the linkage between springs and RPOs for the front springs via a site called Compnine, but they don't really exist anymore. There was data for the rear springs, but I concluded that it really wasn't worth pursuing because everyone should just upgrade to the Z71 rear springs and be much happier.

[JakAttak]

6sk and 7sk RPO code refers to part #15125884 came off my 03 tb ext

[TommyMahoni]

sry for opening this old thread again,
but i try to find the original spring ratio of my front springs so i can get some new springs manufactured by H&R.
I have the rpo's 6SX and 7SW, they aren't in the listing, but 6sx is apparently lavender. I found on https://nemigaparts.com/de/cat_spares/e ... /ts06-103/ a exploded view with all options and part numbers.

Spring, frt - lh T1 SUSP(6SX) 01 15125881

i also found this infos about the 7sw spring
Spring, frt - rh ST1 SUSP(7XN),(7SW) 01 15780417

after searching the web for the parts number i found this:
SKU: 15780417
Positions: Front
Description: Code-6es,7es,6sw,7sw,6xn,7xn.

Do i get right, that the left and right spring has different spring ratios?

i appreciate the knowledge in this forum, i spend hours of reading, but the front suspension confuses myself very hard

Greetings from Germany