Leaf Spring code?

[bergy]

I decided to freshen up my '69 Pace Car for my winter project.  This car gets driven a lot, so the old resto is starting to show its age.  I was cleaning up the leaf springs and noticed a "GM" stamping with a "U" beside it on the main leaf.  Not sure if it's the original leaf spring or not - has anyone seen this before?  Is the "U" a spring code?  They are 5 leaf springs.

[68camaroz28]

Its original! I found it on 6 of my 8 leafs on our 68 4ply leaf springs. Normally found on the main leafs and seems to be sporadic on others from when I researched the topic a couple of years ago. U is not a spring code that I have ever read! I thought or read somewhere it was the 'C' turned 90 degrees..
Go here to post 201 (our 68Z build thread) to see some of our GMC embossed leafs.
http://www.camaros.net/forums/showthread.php?t=182584&page=14

[bergy]

Thanks for the info.  As I'm cleaning them up, I noticed that 3 of the passemger side individual leafs have the "GMU" (or GMC) mark & 4 of the leafs on the driver's side have it.  The smallest leaf on both sides doesn't have it.  I've taken apart a lot of these cars & never noticed that little stamp before :-)

[bertfam]

It's still under research, but not all original springs have the GM casting. Not sure why some do and some don't, but so far there seems to be no rhyme or reason!

Ed

[bergy]

It may just be imbedded in the sizing roller - so every full length of stock gets embossed at equal intervals.  When the full lengths are cut to rough leaf size - some pieces retain the embossing and some don't (depending on where the full length of stock was cut).  Just a thought....

[69Z28-RS]

that was my thought as well Bergy... 

[JohnZ]

Many midyear Corvette rear leaf springs have "GLS" debossed on the edge of the leaves, and our research with Rockwell and Ontario Steel Products (who manufactured the springs) disclosed that the "GLS" stood for Great Lakes Steel, who supplied the SAE 5140 strip stock the springs were made from. The "GMU" on Camaro leaf springs must identify a different steel supplier to Chevrolet-Livonia Spring & Bumper, who manufactured the Camaro springs.

[bergy]

Makes sense - thanks John

[lynnbilodeau]

Speaking of codes, page 57 of the AIM (69) indicates color code stripe at the front eye of the leaf spring assy.

I have asked this before on another board.

Anyone know the color codes?

Even if yoiu don't know them all, anyone know the corrct color for the Z/28 rear spring?

[bergy]

Interesting that 5140 has a fairly high chrome specification and would commonly fall into the stainless steel range.  I'm thinking that they must have hugged the lower allowable range of chrome though based on the way these springs rusted!

[camaro cat]

I just reread this post & this time as I looked at the picture of the edge of the spring, it immediately struck me that  the embossed letters are not "GMU" but "GM-U". Not a big deal but if it helps in determining the source for this detail, then hopefully I've made a small contribution.

Loren

[lynnbilodeau]

So what color is the paint stripe on Z/28 springs.

[Mike S]

So what color is the paint stripe on Z/28 springs.

Lynn,

  I believe the spring color coding was a 67 thing prior to using a label to identify rear springs
I raised that question last year. You can review it here:
http://www.camaros.org/forum/index.php?topic=9739.0

Mike

[lynnbilodeau]

Thanks Mike.

There were lots of part had numbers, etc. but still were coded with a swab of paint.  Distributors, spindles, even my original fuel line had dark green paint on it.  I believe it was for easy id on the line.

Anyway, page 57 of the 1969 model AIM shows the location for the "color code stripe".  Seems like they would have figured out is was non existent after two years.