I could use a differential pic - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jmil1974 · 10-10-2002, 09:07 AM

This seems very silly I know but this is one of those knowledge holes I am trying to fill. Does anyone have a pic of their diff with the cover off? I am trying to determine if I have posi or not. I changed the fluid last night and it seems as though I do. There is a housing in there that looks like many I have seen, though it has gears and not clutches. Having never (recently) seen an open diff naked to compare to (or any other for that matter), I am not 100% certain of what I was looking at. I know there were a helluva lot more gears in there than just a ring and pinion (2 or 3 more inside that bell-shaped housing). Any help would be greatly appreciated. It would be of some comfort to know I have posi, even with the way too sluggish 3.07/3.08s. Thanks!
Jason

Pont · 10-10-2002, 09:11 AM

Jason, can you get on it enough to break the tires loose? Do you leave two black patches? From what you described, it sounds like a limited slip diff to me. Did you happen to notice a spring pack assembly in the carrier?

Sorry, I can't help with a pic.

**1971Stepside** · 10-10-2002, 09:13 AM

Unfortunately I don't have a pic here at work to show you, but the easiest way to tell is Jack up both sides and spin a wheel. If they both go I would say you have a posi.

I thought the same thing when I opened up my pumkin, but it was a standard rearend.

I'm sure someone will show you a picture. Check down a page or two as there is always an "identify this rearend" post.

jmil1974 · 10-10-2002, 09:26 AM

Well, she's up on jackstands at the moment. When I spin one, both spin. I can barely rmember the last time I drove her (2 years+), much less lit 'em up -- though I intend to remedy that in just a couple weeks.

Thanks for the help fellas,
Jason

Pont · 10-10-2002, 09:31 AM

Do they both spin in the same direction, or if you spin one, does the other spin in the opposit direction?

jmil1974 · 10-10-2002, 09:52 AM

I'll have to double check tonight but I believe the same direction.

Pont · 10-10-2002, 09:53 AM

well, that should take care of that question for ya then. Same direction is posi, opposite direction is limited slip.

jmil1974 · 10-10-2002, 10:30 AM

Well, I did a search as suggested and saw a pic that looked like mine, says it's open. Only thing is that I couldn't see in the housing window very well as it was facing mostly up. All I could see was the edge of one spider gear. Ah well, I guess I'll just wait until I drive it and find out for sure since it's already buttoned up and full o' fluid.

Thanks guys!

Wasted Income · 10-10-2002, 02:04 PM

You can't rely on the directions that the wheels spin to determine if, much less what type of differential you have. An open diff will also spin the wheels in opposite directions when up on jack stands (when you spin one wheel with your hand)

Here is what an ARB air locker looks like

Wasted Income · 10-10-2002, 02:04 PM

here's a Detroit locker

Wasted Income · 10-10-2002, 02:05 PM

here's a Powertrax Lockrite

Wasted Income · 10-10-2002, 02:07 PM

and here's an Auburn. GM positraction differentials also look similar to this. If you saw this, you have posi. If you saw 4 gears with a cross-pin inside the carrier, you have an open diff.

Sometimes, under the right conditions, an open diff will leave two blackies, or two burnout marks in the gravel. The only way to be positive is to pull the cover and look.

-Jeff

jmil1974 · 10-10-2002, 02:41 PM

67SL1SWB,

Thank you very much!

Estanley · 10-10-2002, 03:32 PM

I am told it is a:

"That differential is a limited slip or as some people say one wheel wonder. It's not a posi or a locker just a plain differential."

Wasted Income · 10-11-2002, 01:16 AM

That is not a limited slip. That is your run of the mill open diff (peg leg, one wheel wonder, etc, etc)

-Jeff

BobbyK · 10-11-2002, 02:48 AM

Here is what's in my 71's 12 bolt.
It's a Eaton GovLoc.

mikep · 10-11-2002, 11:49 AM

On Dana 60 posi's the easist way to tell is by looking at the carrier. The Posi ones have 4 spiders and have bolts on the end of the carrier to disasseble it. Non posi have 2 spiders and have no bolts on the end.. The clutches are burried on either side and are not visible .

10-10-2002, 09:07 AM	#1
jmil1974 Ain't we cute? Join Date: May 2002 Location: Friendswood, TX Posts: 700	I could use a differential pic This seems very silly I know but this is one of those knowledge holes I am trying to fill. Does anyone have a pic of their diff with the cover off? I am trying to determine if I have posi or not. I changed the fluid last night and it seems as though I do. There is a housing in there that looks like many I have seen, though it has gears and not clutches. Having never (recently) seen an open diff naked to compare to (or any other for that matter), I am not 100% certain of what I was looking at. I know there were a helluva lot more gears in there than just a ring and pinion (2 or 3 more inside that bell-shaped housing). Any help would be greatly appreciated. It would be of some comfort to know I have posi, even with the way too sluggish 3.07/3.08s. Thanks! Jason __________________ 69 C10 2WD LWB Fleet 350/350 power front disc conversion (6 lug disc kit from gmcpauls) and new engine, PS, A/C, fresh fluids, SHE DRIVES! FOR SALE $3900

10-10-2002, 09:11 AM	#2
Pont I need another Barley Pop Join Date: Feb 2001 Location: Grants Pass, OR Posts: 1,629	Jason, can you get on it enough to break the tires loose? Do you leave two black patches? From what you described, it sounds like a limited slip diff to me. Did you happen to notice a spring pack assembly in the carrier? Sorry, I can't help with a pic. __________________ 67 Short Fleet 4x4 04 Honda CRF450R 89 Toyota 4-Runner 34 Ford 2 door sedan - Long term project ---------------------------------------------- There is a very fine line between "hobby" and "mental illness"

10-10-2002, 09:13 AM	#3
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Unfortunately I don't have a pic here at work to show you, but the easiest way to tell is Jack up both sides and spin a wheel. If they both go I would say you have a posi. I thought the same thing when I opened up my pumkin, but it was a standard rearend. I'm sure someone will show you a picture. Check down a page or two as there is always an "identify this rearend" post. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

10-10-2002, 09:26 AM	#4
jmil1974 Ain't we cute? Join Date: May 2002 Location: Friendswood, TX Posts: 700	Well, she's up on jackstands at the moment. When I spin one, both spin. I can barely rmember the last time I drove her (2 years+), much less lit 'em up -- though I intend to remedy that in just a couple weeks. Thanks for the help fellas, Jason __________________ 69 C10 2WD LWB Fleet 350/350 power front disc conversion (6 lug disc kit from gmcpauls) and new engine, PS, A/C, fresh fluids, SHE DRIVES! FOR SALE $3900

10-10-2002, 09:31 AM	#5
Pont I need another Barley Pop Join Date: Feb 2001 Location: Grants Pass, OR Posts: 1,629	Do they both spin in the same direction, or if you spin one, does the other spin in the opposit direction? __________________ 67 Short Fleet 4x4 04 Honda CRF450R 89 Toyota 4-Runner 34 Ford 2 door sedan - Long term project ---------------------------------------------- There is a very fine line between "hobby" and "mental illness"

10-10-2002, 09:52 AM	#6
jmil1974 Ain't we cute? Join Date: May 2002 Location: Friendswood, TX Posts: 700	I'll have to double check tonight but I believe the same direction. __________________ 69 C10 2WD LWB Fleet 350/350 power front disc conversion (6 lug disc kit from gmcpauls) and new engine, PS, A/C, fresh fluids, SHE DRIVES! FOR SALE $3900

10-10-2002, 09:53 AM	#7
Pont I need another Barley Pop Join Date: Feb 2001 Location: Grants Pass, OR Posts: 1,629	well, that should take care of that question for ya then. Same direction is posi, opposite direction is limited slip. __________________ 67 Short Fleet 4x4 04 Honda CRF450R 89 Toyota 4-Runner 34 Ford 2 door sedan - Long term project ---------------------------------------------- There is a very fine line between "hobby" and "mental illness"

10-10-2002, 10:30 AM	#8
jmil1974 Ain't we cute? Join Date: May 2002 Location: Friendswood, TX Posts: 700	Well, I did a search as suggested and saw a pic that looked like mine, says it's open. Only thing is that I couldn't see in the housing window very well as it was facing mostly up. All I could see was the edge of one spider gear. Ah well, I guess I'll just wait until I drive it and find out for sure since it's already buttoned up and full o' fluid. Thanks guys! __________________ 69 C10 2WD LWB Fleet 350/350 power front disc conversion (6 lug disc kit from gmcpauls) and new engine, PS, A/C, fresh fluids, SHE DRIVES! FOR SALE $3900

10-10-2002, 02:04 PM	#9
Wasted Income Boosted Member Join Date: May 2002 Location: Mackinaw, IL Posts: 2,200	You can't rely on the directions that the wheels spin to determine if, much less what type of differential you have. An open diff will also spin the wheels in opposite directions when up on jack stands (when you spin one wheel with your hand) Here is what an ARB air locker looks like Attached Images __________________ 1972 2wd K/5 Blazer Turbocharged 370 LSx - 941 rwhp / 1093 rwtq 1969 Chevy K-10 L33 5.3 / 4L80E / NP241 / 4" lift 1964 Buick Skylark Twin TURBO 383 LS pro-touring project 2014 VW Passat TDI - Daily Driver Turbo diesel 2015 Sierra Denali HD Duramax Turbo diesel 2023 Ford Explorer ST - Twin Turbskis 2023 Ford F150 RCSB - Whipple Supercharged 2017 Polaris RZR Turbo 2014 Nor-Tech Center Console - Twin Supercharged Outboards *TURBO ALL THE THINGS!!*

10-10-2002, 02:04 PM	#10
Wasted Income Boosted Member Join Date: May 2002 Location: Mackinaw, IL Posts: 2,200	here's a Detroit locker Attached Images __________________ 1972 2wd K/5 Blazer Turbocharged 370 LSx - 941 rwhp / 1093 rwtq 1969 Chevy K-10 L33 5.3 / 4L80E / NP241 / 4" lift 1964 Buick Skylark Twin TURBO 383 LS pro-touring project 2014 VW Passat TDI - Daily Driver Turbo diesel 2015 Sierra Denali HD Duramax Turbo diesel 2023 Ford Explorer ST - Twin Turbskis 2023 Ford F150 RCSB - Whipple Supercharged 2017 Polaris RZR Turbo 2014 Nor-Tech Center Console - Twin Supercharged Outboards *TURBO ALL THE THINGS!!*

10-10-2002, 02:05 PM	#11
Wasted Income Boosted Member Join Date: May 2002 Location: Mackinaw, IL Posts: 2,200	here's a Powertrax Lockrite Attached Images __________________ 1972 2wd K/5 Blazer Turbocharged 370 LSx - 941 rwhp / 1093 rwtq 1969 Chevy K-10 L33 5.3 / 4L80E / NP241 / 4" lift 1964 Buick Skylark Twin TURBO 383 LS pro-touring project 2014 VW Passat TDI - Daily Driver Turbo diesel 2015 Sierra Denali HD Duramax Turbo diesel 2023 Ford Explorer ST - Twin Turbskis 2023 Ford F150 RCSB - Whipple Supercharged 2017 Polaris RZR Turbo 2014 Nor-Tech Center Console - Twin Supercharged Outboards *TURBO ALL THE THINGS!!*

10-10-2002, 02:07 PM	#12
Wasted Income Boosted Member Join Date: May 2002 Location: Mackinaw, IL Posts: 2,200	and here's an Auburn. GM positraction differentials also look similar to this. If you saw this, you have posi. If you saw 4 gears with a cross-pin inside the carrier, you have an open diff. Sometimes, under the right conditions, an open diff will leave two blackies, or two burnout marks in the gravel. The only way to be positive is to pull the cover and look. -Jeff Attached Images __________________ 1972 2wd K/5 Blazer Turbocharged 370 LSx - 941 rwhp / 1093 rwtq 1969 Chevy K-10 L33 5.3 / 4L80E / NP241 / 4" lift 1964 Buick Skylark Twin TURBO 383 LS pro-touring project 2014 VW Passat TDI - Daily Driver Turbo diesel 2015 Sierra Denali HD Duramax Turbo diesel 2023 Ford Explorer ST - Twin Turbskis 2023 Ford F150 RCSB - Whipple Supercharged 2017 Polaris RZR Turbo 2014 Nor-Tech Center Console - Twin Supercharged Outboards *TURBO ALL THE THINGS!!*

10-10-2002, 02:41 PM	#13
jmil1974 Ain't we cute? Join Date: May 2002 Location: Friendswood, TX Posts: 700	67SL1SWB, Thank you very much! __________________ 69 C10 2WD LWB Fleet 350/350 power front disc conversion (6 lug disc kit from gmcpauls) and new engine, PS, A/C, fresh fluids, SHE DRIVES! FOR SALE $3900

10-10-2002, 03:32 PM	#14
Estanley Registered User Join Date: Nov 2001 Location: Eatonton, GA, USA Posts: 191	I am told it is a: "That differential is a limited slip or as some people say one wheel wonder. It's not a posi or a locker just a plain differential." Attached Images

10-11-2002, 01:16 AM	#15
Wasted Income Boosted Member Join Date: May 2002 Location: Mackinaw, IL Posts: 2,200	That is not a limited slip. That is your run of the mill open diff (peg leg, one wheel wonder, etc, etc) -Jeff __________________ 1972 2wd K/5 Blazer Turbocharged 370 LSx - 941 rwhp / 1093 rwtq 1969 Chevy K-10 L33 5.3 / 4L80E / NP241 / 4" lift 1964 Buick Skylark Twin TURBO 383 LS pro-touring project 2014 VW Passat TDI - Daily Driver Turbo diesel 2015 Sierra Denali HD Duramax Turbo diesel 2023 Ford Explorer ST - Twin Turbskis 2023 Ford F150 RCSB - Whipple Supercharged 2017 Polaris RZR Turbo 2014 Nor-Tech Center Console - Twin Supercharged Outboards *TURBO ALL THE THINGS!!*



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10-11-2002, 02:48 AM	#16
BobbyK Registered User Join Date: May 2000 Location: Petrolia,Ontario,Canada but working in Port Huron,Mi. Posts: 1,772	Here is what's in my 71's 12 bolt. It's a Eaton GovLoc. __________________ 71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE

10-11-2002, 11:49 AM	#17
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	On Dana 60 posi's the easist way to tell is by looking at the carrier. The Posi ones have 4 spiders and have bolts on the end of the carrier to disasseble it. Non posi have 2 spiders and have no bolts on the end.. The clutches are burried on either side and are not visible . __________________ No truck :-(

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