Posi experts please????????? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Longhorn · 05-06-2002, 05:59 PM

Grandson's 71 with posi pops when taking off going around corners. Seems to be ok on straight pull. Truck has 250K on it. I purchased GM additive but not add it yet. What else can I expect? Are the clutchs for these still available if I have to tear her down? Thanks for your help.

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Bill

Rapid City, SD

67 short stepside, in weeds 6Cyl
69 Longhorn CST 396 nice original

shortbed70 · 05-06-2002, 06:07 PM

I'm not an expert but I do know that most posis make some sort of noise weather it be a poping or whinning clicking so forth. I cont know how to rebuild these fine units but I wish you good luck.

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1970 shortbed(project)
350/350 dropped 4/6 21/2" flowmasters. Dropping bigblock idea and building a stout smallblock...

texnician01 · 05-06-2002, 06:16 PM

I believe that the clutches are still available, they were made by Eaton. I'm not an expert by any means though.

Nathan

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1969 C-10 292 I-6 4 spd in the middle of a restoration. going to get a 327 and 3.07 gears but keeping all of the original parts so I can put it back to original later on down the road.
55 chevy 4 door 150
47 Willys CJ-2A

**COBALT** · 05-06-2002, 06:24 PM

Randy's Ring & Pinion

Mike C · 05-06-2002, 06:24 PM

Sounds like the lubricant is contaminated. Drain and refill with appropriate rear oil and the GM positrac friction modifier additive. Might be a good time for a pinion seal and axle seals as well as the new cover gasket. It is possible to get rebuild parts. I went through my Eaton posi about 12 years ago. Clutches were about $50 a set back then and springs about $10 for 4.

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70 GMC 3/4 ton Sierra Grande 402/TH400
72 Jimmy 4WD 4spd 4" & 35's
64 Corvette Coupe
68 Camaro 'vert TPI & TH700
69 Z/28 355 12.6's @110
72 Datsun 240Z-ol' reliable

JW · 05-07-2002, 01:11 PM

Used to race Corvettes,16 years, have a Posi in my 72. The "POP" is the Posi plates releasing. Problem is either worn Posi plates, posi springs or both. To remove a posi is not to bad, to install can be dangerous. The posi pack, plates and springs, have to be compressed for installation. We use two C clamps, then tap the pack in. If not done right the pack will come apart. I installed a rear end cooler on my truck, adds to the life of the posi.

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72 Cheyenne Super, Fleetside, Shortbed,
Original Owner, Special Ordered
350ci/340hp, Auto Trans, 3:70 Posi, Tow Package
Northern Calif

HuggerCST · 05-07-2002, 02:42 PM

I had one years ago in a '72 that started popping like that. I changed the fluid, put in the GM additive, and the popping stopped. Never had another problem with it.

05-06-2002, 05:59 PM	#1
Longhorn Registered User Join Date: Mar 2001 Location: Rapid City, South Dakota Posts: 222	Posi experts please????????? Grandson's 71 with posi pops when taking off going around corners. Seems to be ok on straight pull. Truck has 250K on it. I purchased GM additive but not add it yet. What else can I expect? Are the clutchs for these still available if I have to tear her down? Thanks for your help. ------------------ Bill Rapid City, SD 67 short stepside, in weeds 6Cyl 69 Longhorn CST 396 nice original __________________ Bill Rapid City, SD 67 short stepside, in weeds 6Cyl 69 Longhorn CST 396 nice original

05-06-2002, 06:07 PM	#2
shortbed70 Registered User Join Date: Mar 2002 Location: Forney TX Posts: 4,512	I'm not an expert but I do know that most posis make some sort of noise weather it be a poping or whinning clicking so forth. I cont know how to rebuild these fine units but I wish you good luck. ------------------ 1970 shortbed(project) 350/350 dropped 4/6 21/2" flowmasters. Dropping bigblock idea and building a stout smallblock... __________________ Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274

05-06-2002, 06:16 PM	#3
texnician01 Senior Member Join Date: Mar 2002 Location: 12 Miles South of Des Moines, Iowa Posts: 359	I believe that the clutches are still available, they were made by Eaton. I'm not an expert by any means though. Nathan ------------------ 1969 C-10 292 I-6 4 spd in the middle of a restoration. going to get a 327 and 3.07 gears but keeping all of the original parts so I can put it back to original later on down the road. 55 chevy 4 door 150 47 Willys CJ-2A __________________ 69 C-10, 340HP 327 55 chevy 4 door 150 47 Willys CJ-2A 05 Harley Night Train 06 1200 Sportster (Wife's bike) 70 Honda CL350 OIF2 & OIF7 Veteran Nathan & Tiffany

05-06-2002, 06:24 PM	#4
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Randy's Ring & Pinion __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

05-06-2002, 06:24 PM	#5
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,713	Sounds like the lubricant is contaminated. Drain and refill with appropriate rear oil and the GM positrac friction modifier additive. Might be a good time for a pinion seal and axle seals as well as the new cover gasket. It is possible to get rebuild parts. I went through my Eaton posi about 12 years ago. Clutches were about $50 a set back then and springs about $10 for 4. ------------------ 70 GMC 3/4 ton Sierra Grande 402/TH400 72 Jimmy 4WD 4spd 4" & 35's 64 Corvette Coupe 68 Camaro 'vert TPI & TH700 69 Z/28 355 12.6's @110 72 Datsun 240Z-ol' reliable __________________ 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

05-07-2002, 01:11 PM	#6
JW Registered User Join Date: Apr 2000 Location: Carmichael, Ca Posts: 67	Used to race Corvettes,16 years, have a Posi in my 72. The "POP" is the Posi plates releasing. Problem is either worn Posi plates, posi springs or both. To remove a posi is not to bad, to install can be dangerous. The posi pack, plates and springs, have to be compressed for installation. We use two C clamps, then tap the pack in. If not done right the pack will come apart. I installed a rear end cooler on my truck, adds to the life of the posi. ------------------ 72 Cheyenne Super, Fleetside, Shortbed, Original Owner, Special Ordered 350ci/340hp, Auto Trans, 3:70 Posi, Tow Package Northern Calif __________________ 72 Cheyenne Super, Fleetside, Shortbed, Original Owner, Special Ordered 350ci/340hp, Auto Trans, 3:70 Posi, Tow Package Northern Calif

05-07-2002, 02:42 PM	#7
HuggerCST Registered User Join Date: Jul 2001 Location: North Louisiana Posts: 4,501	I had one years ago in a '72 that started popping like that. I changed the fluid, put in the GM additive, and the popping stopped. Never had another problem with it. __________________ Wynne 70 CST short fleet Hugger orange & white, 350/350, ps, pb, air, tilt, tach/vac/speedwarning, original buckets, AM/FM, oak bed floor, shoulder belts, 3.5"/5.5" drop, 20" American Racing VN425s. Build thread 53 Chevy shortbed 69 Camaro Click here to subscribe Chevy GMC International Truck Club Louisiana Charter Member http://www.louisianaclassictruckclub.com



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