Which Dana 60 Posi? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

deputyd_0803 · 05-22-2008, 09:30 AM

I have a 72 c20 bbc and dana 60. I am running into a problem keeping tread on ONE of my tires. How do I know which posi/trak-lok/locker, system to go with? I want it streetable still, it is my daily driver, but I want them to lock up together, so I am leaning toward the posi. How do I know which one to go with, 16, 30, 35 spline? I also have 4.10's per the glove box sheet. Think I would like to change that to 3.73 or something like that if possible. Any help would be appreciated.

**special-K** · 05-22-2008, 01:40 PM

The standard big block ratio was 3.08:1.I can`t say the spline count off the topof my head.I`d thing the vendor you deal with would know by the application info you supply them with.Does your truck have factory posi,Power-Loc,now?It may be salvageable.It could have the wrong lube/no additive or need some sort of servicing or repair.I like the Power-Loc in my GMC K2500.It only chirps when I want it to.A locker,or GM No-Spin,takestechnique to conserve tires and not chirp everytime cut cut a turn.Definatelt the best traction aid,but just takes technique.

deputyd_0803 · 05-22-2008, 02:40 PM

The glove box sheet doesn't say posi. I have done the lift rearend and rotate one wheel. The other goes opposite way. No plates in the carrier either. Sounds like a power lock is what I am looking for... Thanks for your help.

Rod · 05-23-2008, 06:11 AM

C20 would have a 30 spline 3.54 ratio typically if a BB truck. Yours had the optional ratio of a 4.10 placed in it....seen a few that way too. You could find a 3.73 if you so chose too, as that ratio will fit. Posi style in this year and 3/4 ton Dana was a maximum-traction posi.

deputyd_0803 · 05-23-2008, 06:35 AM

Thanks for that help

jeffspower · 05-23-2008, 06:39 AM

For new clutch type diffs, you have a choice of the power- loc or trac- loc.

The trac-loc is the cheapest, but is a 2 spider & crosspin style. It's a pain to replace clutches in. It works solely on plate preload- meaning it has to be set up with tight plate pressure to keep both wheels under power when traction is unequal. So it tends to spin the inside tire when turning fairly easily.

The power- loc is about twice the price, but is a split case design that bolts together, making clutch replacement easy. It is also a 4 spider setup with a "cross" instead of a pin. It's pretty tough. The cross "ramps" under load to apply force to the clutches, so it hooks harder when needed & grabs less when turning.

05-22-2008, 09:30 AM	#1
deputyd_0803 Registered User Join Date: Apr 2008 Location: St. George, UT Posts: 77	Which Dana 60 Posi? I have a 72 c20 bbc and dana 60. I am running into a problem keeping tread on ONE of my tires. How do I know which posi/trak-lok/locker, system to go with? I want it streetable still, it is my daily driver, but I want them to lock up together, so I am leaning toward the posi. How do I know which one to go with, 16, 30, 35 spline? I also have 4.10's per the glove box sheet. Think I would like to change that to 3.73 or something like that if possible. Any help would be appreciated. __________________ The ONLY way to go. 1972 C20 Custom Deluxe: Rebuilt 402 hopped up a bit, th400 with shift kit, Dana 60(wanna have posi), New solid, no cancer, cab. B & M Starshifter floor shifter.

05-22-2008, 01:40 PM	#2
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,859	Re: Which Dana 60 Posi? The standard big block ratio was 3.08:1.I can`t say the spline count off the topof my head.I`d thing the vendor you deal with would know by the application info you supply them with.Does your truck have factory posi,Power-Loc,now?It may be salvageable.It could have the wrong lube/no additive or need some sort of servicing or repair.I like the Power-Loc in my GMC K2500.It only chirps when I want it to.A locker,or GM No-Spin,takestechnique to conserve tires and not chirp everytime cut cut a turn.Definatelt the best traction aid,but just takes technique. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

05-22-2008, 02:40 PM	#3
deputyd_0803 Registered User Join Date: Apr 2008 Location: St. George, UT Posts: 77	Re: Which Dana 60 Posi? The glove box sheet doesn't say posi. I have done the lift rearend and rotate one wheel. The other goes opposite way. No plates in the carrier either. Sounds like a power lock is what I am looking for... Thanks for your help. __________________ The ONLY way to go. 1972 C20 Custom Deluxe: Rebuilt 402 hopped up a bit, th400 with shift kit, Dana 60(wanna have posi), New solid, no cancer, cab. B & M Starshifter floor shifter.

05-23-2008, 06:11 AM	#4
Rod Join Date: Dec 1999 Location: Eastern - Manitoba Canada, Winnipeg Posts: 4,369	Re: Which Dana 60 Posi? C20 would have a 30 spline 3.54 ratio typically if a BB truck. Yours had the optional ratio of a 4.10 placed in it....seen a few that way too. You could find a 3.73 if you so chose too, as that ratio will fit. Posi style in this year and 3/4 ton Dana was a maximum-traction posi. __________________ Senior active founding member. 70 3/4 ton GMC Suburban 4x4 250/4 spd. 71 1/2 ton Suburban Chevy 4x4, 350/350 72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane 2005 FLSTSCI Harley Springer 85 FXSB Harley Lowrider 72 Triumph 650 Bonneville 5spd "Poor people don't have hobbies" Quote from wife.

05-23-2008, 06:35 AM	#5
deputyd_0803 Registered User Join Date: Apr 2008 Location: St. George, UT Posts: 77	Re: Which Dana 60 Posi? Thanks for that help __________________ The ONLY way to go. 1972 C20 Custom Deluxe: Rebuilt 402 hopped up a bit, th400 with shift kit, Dana 60(wanna have posi), New solid, no cancer, cab. B & M Starshifter floor shifter.

05-23-2008, 06:39 AM	#6
jeffspower Well, Whoop-dee-do! Join Date: Mar 2003 Location: Easton, Mo. pop.- me & scarcely a few others Posts: 2,302	Re: Which Dana 60 Posi? For new clutch type diffs, you have a choice of the power- loc or trac- loc. The trac-loc is the cheapest, but is a 2 spider & crosspin style. It's a pain to replace clutches in. It works solely on plate preload- meaning it has to be set up with tight plate pressure to keep both wheels under power when traction is unequal. So it tends to spin the inside tire when turning fairly easily. The power- loc is about twice the price, but is a split case design that bolts together, making clutch replacement easy. It is also a 4 spider setup with a "cross" instead of a pin. It's pretty tough. The cross "ramps" under load to apply force to the clutches, so it hooks harder when needed & grabs less when turning. __________________ '68 GMC shortbox 4x4 350/SM465/T221- bought it in '83 SOLD '72 K20 500 Cad/TH400/NP205 SOLD '92 Chevy 2500 6.5 mech TD 4L80E crusty daily driver '72 Monte Carlo... sweet low mile toy '11 Dodge Challenger IE 392 6spd... midlife car



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