What is RPO code YD3? ("Proc Opt Axle") - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Number21 · 09-01-2009, 08:36 PM

I have a '79 C30 with the 14 bolt FF rear end. I didn't think there was anything special about it until I noticed I could do 2 legged burnouts.

I have the original build sheet and it lists RPO code "YD3" and says "PROC OPT AXLE". What does that mean in english?

**N2TRUX** · 09-01-2009, 11:03 PM

PROfessional COP Twin AXLE. This was a very rare option that was available to law enforcement agencies only.

I have no idea what it really means...

Keith Seymore · 09-02-2009, 07:15 AM

I suspect it means "Processing Optional Axle" or "Process Option: Axle".

Within the engineering release there are several different kinds of codes: RPOs (Regular Production Options); SEOs (Special Equipment Options, like for fleets) Non Merchandising Options and Processing Options.

The latter two are not offered to the public but are internal options used to keep the release strings straight, to provide cross balance or to provide a general option family that more specific (selectable) options fall under.

Said differently, Non Merchandising Options and Processing Options are not ones that you can go to the dealership and choose; they just help keep everything straight within the assembly plant.

I suspect your truck has the base axle (my book says "YD3 - base equipment"). That big C30 axle probably has enough drag in the open differential to allow you to do "two legged burnouts".

K

b454rat · 09-02-2009, 09:05 AM

Only thing I can find is:

YD3 : FRONT AXLE, BASE EQUIPMENT FOR SCHEDULING, GVW PLATE

09-01-2009, 08:36 PM	#1
Number21 Registered User Join Date: Aug 2009 Location: Oregon Posts: 611	What is RPO code YD3? ("Proc Opt Axle") I have a '79 C30 with the 14 bolt FF rear end. I didn't think there was anything special about it until I noticed I could do 2 legged burnouts. I have the original build sheet and it lists RPO code "YD3" and says "PROC OPT AXLE". What does that mean in english?

09-01-2009, 11:03 PM	#2
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Re: What is RPO code YD3? ("Proc Opt Axle") PROfessional COP Twin AXLE. This was a very rare option that was available to law enforcement agencies only. I have no idea what it really means... __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

09-02-2009, 07:15 AM	#3
Keith Seymore Registered User Join Date: May 2009 Location: Motor City Posts: 9,226	Re: What is RPO code YD3? ("Proc Opt Axle") I suspect it means "Processing Optional Axle" or "Process Option: Axle". Within the engineering release there are several different kinds of codes: RPOs (Regular Production Options); SEOs (Special Equipment Options, like for fleets) Non Merchandising Options and Processing Options. The latter two are not offered to the public but are internal options used to keep the release strings straight, to provide cross balance or to provide a general option family that more specific (selectable) options fall under. Said differently, Non Merchandising Options and Processing Options are not ones that you can go to the dealership and choose; they just help keep everything straight within the assembly plant. I suspect your truck has the base axle (my book says "YD3 - base equipment"). That big C30 axle probably has enough drag in the open differential to allow you to do "two legged burnouts". K __________________ Chevrolet Flint Assembly 1979-1986 GM Full Size Truck Engineering 1986 - 2019 Intro from an Old Assembly Guy: http://67-72chevytrucks.com/vboard/s...d.php?t=342926 My Pontiac story: http://forums.maxperformanceinc.com/...d.php?t=560524 Chevelle intro: http://www.superchevy.com/features/s...hevy-chevelle/ Last edited by Keith Seymore; 09-02-2009 at 07:16 AM.

09-02-2009, 09:05 AM	#4
b454rat Senior Member Join Date: May 2004 Location: Binghamton, NY Posts: 3,469	Re: What is RPO code YD3? ("Proc Opt Axle") Only thing I can find is: YD3 : FRONT AXLE, BASE EQUIPMENT FOR SCHEDULING, GVW PLATE __________________ 2000 GMC CCSB 454/4L80 6” lift SAS 1999 Chevy CCSB 454/NV4500 4” SAS 1999 GMC Yukon 350/4L60 6" SAS



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