Service Parts Identification question. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72timemachine · 04-13-2020, 07:54 AM

If the spi sheet on the glove box door makes no mention of the rear end in your truck, would that indicate you do not have a limited slip rear end? This is the case on one of my '69 c30 parts trucks which has a ho72 rear end.

Conversely, my '72 C10 Cheyenne's spi has the posi-traction rear end listed. So the question is, if it is not listed as a posi-traction rear end on the spi, does that mean it's an open carrier rear end or would I have to jack up the rear end and do some further investigating?

Thank you for any help.

**Joesjunk** · 04-13-2020, 10:18 AM

posi-traction was an option, so if it’s not listed then it doesn’t have it.

Mike C · 04-13-2020, 12:57 PM

With the caveat that it hasn't been changed. 50 years into the life of a working truck, all bets are off as to what you have now.

But it originally did not come with it.

Killer Bee · 04-13-2020, 01:38 PM

of course nothing beats opening it up and inspecting what's in there to be sure..

but these are only suggestions for clues as to what may have been installed from the factory..

Dana or GM diffs would likely have 'positraction axle' on the SPID..

first column, third line;

Eaton H052/72 diffs would likely have 'no spin rear axle' on the SPID..

second column, fourth line;

if the Eaton input pinion cover is original and not ever been tampered with, this tag is the tell from the factory..

nothing on the tag but its presence indicates no spin locker installed when it was assembled at the factory..

mentioned and also pictured in this article;
https://www.stovebolt.com/techtips/a...Ton%20Upgrade/

and then there's the ultimate score, front and rear positraction

from this post in the SPID thread, more comments followed..

http://67-72chevytrucks.com/vboard/s...&postcount=946

last line of both columns;

courtesy of member Canuckvetter

04-13-2020, 07:54 AM	#1
72timemachine Registered User Join Date: Oct 2008 Location: los angeles ca Posts: 220	Service Parts Identification question. If the spi sheet on the glove box door makes no mention of the rear end in your truck, would that indicate you do not have a limited slip rear end? This is the case on one of my '69 c30 parts trucks which has a ho72 rear end. Conversely, my '72 C10 Cheyenne's spi has the posi-traction rear end listed. So the question is, if it is not listed as a posi-traction rear end on the spi, does that mean it's an open carrier rear end or would I have to jack up the rear end and do some further investigating? Thank you for any help.

04-13-2020, 10:18 AM	#2
Joesjunk Senior Member Join Date: May 2001 Location: Independence MO. Posts: 7,709	Re: Service Parts Identification question. posi-traction was an option, so if it’s not listed then it doesn’t have it. __________________ 72 3/4t Custom Deluxe 402/auto 66k Original paint 71 3/4t 4x4 Custom Deluxe 10k original miles Original paint 71 3/4t Cheyenne 402 70k original paint 72 3/4t 4x4 Custom deluxe 72 3/4t 4x4 Custom deluxe 91k original paint 72 Cheyenne/30 Dually 69 Camaro SS396 4-speed 13 GMC 2500HD Duramax I bought new 05 Jeep Wrangler "Willys Edition" 12k miles (I bought new) 85 3/4 ton 4x4 Scottsdale 33k miles original paint 86 1 ton 4x4 SRW Silverado 454 restored 80 1 ton 4x4 SRW Silverado 9,434 original miles!! original paint 95 GMC 1 ton dually 4x4 my dad bought new 95 GMC 3/4 ton 4x4, regular cab 454, 31k original miles 2002 2500HD 4x4 regular cab 6.0L 67k miles 2002 2500HD 4x4 regular cab 8.1L 28k miles 2003 GMC 2500HD 4x4 regular cab Diesel 93k miles 67-72 Parts for sale

04-13-2020, 12:57 PM	#3
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,728	Re: Service Parts Identification question. With the caveat that it hasn't been changed. 50 years into the life of a working truck, all bets are off as to what you have now. But it originally did not come with it. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

04-13-2020, 01:38 PM	#4
Killer Bee Registered User Join Date: Jan 2016 Location: Barber City, CA Posts: 4,816	Re: Service Parts Identification question. of course nothing beats opening it up and inspecting what's in there to be sure.. but these are only suggestions for clues as to what may have been installed from the factory.. Dana or GM diffs would likely have 'positraction axle' on the SPID.. first column, third line; Eaton H052/72 diffs would likely have 'no spin rear axle' on the SPID.. second column, fourth line; if the Eaton input pinion cover is original and not ever been tampered with, this tag is the tell from the factory.. nothing on the tag but its presence indicates no spin locker installed when it was assembled at the factory.. mentioned and also pictured in this article; https://www.stovebolt.com/techtips/a...Ton%20Upgrade/ and then there's the ultimate score, front and rear positraction from this post in the SPID thread, more comments followed.. http://67-72chevytrucks.com/vboard/s...&postcount=946 last line of both columns; courtesy of member Canuckvetter __________________ *I started out with nothing - and I still have most of it*



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