5 Lug 373 Posi Rear End ?????? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

flashed · 07-03-2019, 11:02 PM

Was there a real 373 5 lug Posi rear end from GM using Eaton Gears or were they linited slip ? A guy told me today he had a GM 12 bolt rear with factory Eaton Posi for sale . If its real Im interested in it and also what would it be worth if real ?

flashed · 07-04-2019, 01:43 PM

TTT , I know nothing about rear gears but would love a Posi in my next build if its real .

**mongocanfly** · 07-04-2019, 02:09 PM

I'd pop the cover off of it and have a looksee....cant always go on what someone "thinks" it is..

flashed · 07-04-2019, 02:29 PM

Thats the problem , I dont know what to look for to tell if its a Posi . Did GM make a true Posi for trucks like the did for Chevelle's ?

68Gold/white · 07-04-2019, 02:30 PM

Posi and limited slip mean the same thing to me. If there is a difference, someone post it...

If you know what a posi carrier looks like on a 12 bolt Chevelle, the pickup carrier looks exactly the same!!! Someone post a picture!!!

Posi and limited slip mean (to me) the the gear carrier has clutches in it to allow both axles to turn, when going in a straight line. the clutches slip when going in turns, to allow the axles to "differentially turn".

A locking axle has a mechanical device that senses when both axles are spinning the same RPM and one is not turning as fast, and locks them together, when this happens (my explanation may not sound exact...)

If there's more than one type of rear end that's not a standard open rear end for a 1/2 ton, I'd like to know...

To purchase a 5 lugger rear, as you describe, most folks know what they have. I' m guessing the asking price is over $500.00. Then a question you have to ask, what condition is it in??? Also, If it's been "worked" on, was the work done by someone competent???

If Eaton was the manufacturer of the gear carriers, I have no idea. Seller might be slinging bull to sell for most $$$, an every day thing...I HATE...

flashed · 07-04-2019, 03:34 PM

I have asked him for pics inside , he thinks its original and he also thinks its worth $1000 . I am looking at another one that I know has all new parts inside but waiting on price on it . May be more than Im willing to pay .
I keep gathering parts for a truck thats not even in my possession , Body Shop Jail . I cant wait to build this truck .

**mongocanfly** · 07-04-2019, 03:39 PM

Ok...pull the cover..if you see springs and plates like in 1st pic then it's a posi...
If theres nothing but side and spider heads then it's a open diff as in 2nd pic...
You also know the drill...take a pic and post it if your unsure...somebody will know what it is..
And yes ..older trucks could be ordered with a locker...newer ones got the g80
I wouldnt give a grand for a unknown condition rear...if it was all fresh itd be worth it
Also if its 3.73s it should have 41/11 stamped on the ring gear

flashed · 07-04-2019, 03:57 PM

Thanks Mongo , those pics will help a lot when he sends pics . Im more interested in the local one to me that My buddy has with everything new inside , just waiting on details and price on it .

**mongocanfly** · 07-04-2019, 04:00 PM

Sounds like a plan!.....just noticed you crossed the 12000 post mark...congrats...I guess

Also keep in mind that 12b car and truck diffs arnt the same

Bigdav160 · 07-04-2019, 08:05 PM

Quote:

Posi and limited slip mean the same thing to me. If there is a difference, someone post it...

Well sort of. "positraction" was a term used to sell GM limited slip differentials in the 1960's. Not any different that Chrysler using "sure grip" for their ads or Studebaker using "twin traction".

There are different types of limited slips and their cousin "locking differentials"

flashed · 07-04-2019, 09:34 PM

Thanks everyone for the much needed education , Im buying the one from my Buddy near me that is much more affordable .

**mongocanfly** · 07-04-2019, 09:36 PM

great!..at least you know what your getting that way...

68Gold/white · 07-05-2019, 11:44 AM

Quote:

Originally Posted by Bigdav160

Well sort of. "positraction" was a term used to sell GM limited slip differentials in the 1960's. Not any different that Chrysler using "sure grip" for their ads or Studebaker using "twin traction".

There are different types of limited slips and their cousin "locking differentials"

Yeah, Pontiac had another word for theirs, can't remember it at the moment...

GASoline71 · 07-09-2019, 08:08 PM

Pontiac called it "Safe-T-Track"

Cadillac = "Controlled Traction"
Olds = "Anti-Spin"
Chevy/GMC = "Posi-Traction"
Chrysler = "Sure-Grip"
Ford = "Traction-Lock"

Gary

**HO455** · 07-12-2019, 03:48 PM

That's why GTO's are safer than the rest.

07-03-2019, 11:02 PM	#1
flashed Registered User Join Date: Oct 2009 Location: canton ga Posts: 12,729	5 Lug 373 Posi Rear End ?????? Was there a real 373 5 lug Posi rear end from GM using Eaton Gears or were they linited slip ? A guy told me today he had a GM 12 bolt rear with factory Eaton Posi for sale . If its real Im interested in it and also what would it be worth if real ?

07-04-2019, 01:43 PM	#2
flashed Registered User Join Date: Oct 2009 Location: canton ga Posts: 12,729	Re: 5 Lug 373 Posi Rear End ?????? TTT , I know nothing about rear gears but would love a Posi in my next build if its real .

07-04-2019, 02:09 PM	#3
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,579	Re: 5 Lug 373 Posi Rear End ?????? I'd pop the cover off of it and have a looksee....cant always go on what someone "thinks" it is.. __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

07-04-2019, 02:29 PM	#4
flashed Registered User Join Date: Oct 2009 Location: canton ga Posts: 12,729	Re: 5 Lug 373 Posi Rear End ?????? Thats the problem , I dont know what to look for to tell if its a Posi . Did GM make a true Posi for trucks like the did for Chevelle's ?

07-04-2019, 02:30 PM	#5
68Gold/white Registered User Join Date: Sep 2011 Location: Ark City, Kansas Posts: 3,272	Re: 5 Lug 373 Posi Rear End ?????? Posi and limited slip mean the same thing to me. If there is a difference, someone post it... If you know what a posi carrier looks like on a 12 bolt Chevelle, the pickup carrier looks exactly the same!!! Someone post a picture!!! Posi and limited slip mean (to me) the the gear carrier has clutches in it to allow both axles to turn, when going in a straight line. the clutches slip when going in turns, to allow the axles to "differentially turn". A locking axle has a mechanical device that senses when both axles are spinning the same RPM and one is not turning as fast, and locks them together, when this happens (my explanation may not sound exact...) If there's more than one type of rear end that's not a standard open rear end for a 1/2 ton, I'd like to know... To purchase a 5 lugger rear, as you describe, most folks know what they have. I' m guessing the asking price is over $500.00. Then a question you have to ask, what condition is it in??? Also, If it's been "worked" on, was the work done by someone competent??? If Eaton was the manufacturer of the gear carriers, I have no idea. Seller might be slinging bull to sell for most $$$, an every day thing...I HATE...

07-04-2019, 03:34 PM	#6
flashed Registered User Join Date: Oct 2009 Location: canton ga Posts: 12,729	Re: 5 Lug 373 Posi Rear End ?????? I have asked him for pics inside , he thinks its original and he also thinks its worth $1000 . I am looking at another one that I know has all new parts inside but waiting on price on it . May be more than Im willing to pay . I keep gathering parts for a truck thats not even in my possession , Body Shop Jail . I cant wait to build this truck .

07-04-2019, 03:39 PM	#7
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,579	Re: 5 Lug 373 Posi Rear End ?????? Ok...pull the cover..if you see springs and plates like in 1st pic then it's a posi... If theres nothing but side and spider heads then it's a open diff as in 2nd pic... You also know the drill...take a pic and post it if your unsure...somebody will know what it is.. And yes ..older trucks could be ordered with a locker...newer ones got the g80 I wouldnt give a grand for a unknown condition rear...if it was all fresh itd be worth it Also if its 3.73s it should have 41/11 stamped on the ring gear Attached Images __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver Last edited by mongocanfly; 07-04-2019 at 03:45 PM.

07-04-2019, 03:57 PM	#8
flashed Registered User Join Date: Oct 2009 Location: canton ga Posts: 12,729	Re: 5 Lug 373 Posi Rear End ?????? Thanks Mongo , those pics will help a lot when he sends pics . Im more interested in the local one to me that My buddy has with everything new inside , just waiting on details and price on it .

07-04-2019, 04:00 PM	#9
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,579	Re: 5 Lug 373 Posi Rear End ?????? Sounds like a plan!.....just noticed you crossed the 12000 post mark...congrats...I guess Also keep in mind that 12b car and truck diffs arnt the same __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver Last edited by mongocanfly; 07-04-2019 at 04:07 PM.

07-04-2019, 09:34 PM	#11
flashed Registered User Join Date: Oct 2009 Location: canton ga Posts: 12,729	Re: 5 Lug 373 Posi Rear End ?????? Thanks everyone for the much needed education , Im buying the one from my Buddy near me that is much more affordable .

07-04-2019, 09:36 PM	#12
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,579	Re: 5 Lug 373 Posi Rear End ?????? great!..at least you know what your getting that way... __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

07-12-2019, 03:48 PM	#15
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 10,787	Re: 5 Lug 373 Posi Rear End ?????? That's why GTO's are safer than the rest. __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban the WMB,1991 S(stink)-10 Blazer,1969 GTO, 1970 Javelin, 1952 F2 Ford 4X4, 29 Model A, 72 Firebird. 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377



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