Opinions on posi traction differential - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chevybill · 03-07-2005, 11:38 PM

I am asking for your opinions on which differential unit to buy and a source.

So far, the best buy I have located is on an auburn posi pro unit from jegs.
Powertrax and eaton are a couple of others I have ran across.

The powertrax unit can be installed without removing the ring and pinion (according to jegs customer support).

At this point I am probably going to have to run an automatic th 350 due to cost and I have a 3.73 gear in the rear end presently.

I want to be able to tow with the truck, and would really prefer a 5 spd. manual tranny, but they are very expensive; even used from a salvage yard.

So you thoughts on posi differentials and suppliers, please.

Thanks to everyone

Low69CST · 03-08-2005, 01:19 AM

The powertrax is a locker unit. It'll be more aggressive. That means you'll hear it locking unlocking. Your truck will knot up alot making sharp turns. But when you hit the gas, straight 1 to 1 ratio between your tires

JimKshortstep4x4 · 03-08-2005, 09:03 AM

My preference is the Eaton Posi.

Here is a link to a source.

Jim

http://www.tomsdifferentials.com/tomp.htm

chevybill · 03-08-2005, 09:39 AM

thanks for the replies, so far.

based on the above description, I will probably move away from the powertrax unit, since it is a little more extreme.

please, more opinions

thanks

70c10 · 03-08-2005, 12:50 PM

I got mine from Tom's diffs for $280 and have been happy with it.

Back in Black · 03-08-2005, 02:55 PM

I could be wrong but my mechanic said the Eaton limited slip for a 12 bolt truck is back ordered indefinitely. This could be for just the higher geared rear ends. I have a 3.07 posi with a bad carrier. The lowered geared models may be available.

chevybill · 03-08-2005, 09:51 PM

70 c10, how long ago did you purchase your unit, in summit their price is 449.95, are they tying to take people to the cleaners or what?

Dean23 · 03-08-2005, 09:53 PM

Id go with the eaton myself. At least you can reapir the eaton if needed. with the auburn once the clutch cones wear its pretty much just a throw away piece.

70c10 · 03-08-2005, 11:35 PM

chevybill- my unit is 2 years old. I paid an additional $25 for bearings and races and about $25 shipping from California. I reused my 3:73's and my buddy charged $100 bucks for the swap which took 3 hours. I have about $450 invested in parts, shipping and labor.

cableguy0 · 03-08-2005, 11:48 PM

the eaton is the better unit by far much more durable than the auburn and the powertrax like to blow apart under higher horsepower. toms differentials seems to have the best prices on the eaton posi unit

**'70_402** · 03-24-2005, 01:54 PM

i called toms and they now offer thier eaton posi units for $336, but that is still cheaper than any i have found...

boraxman · 03-24-2005, 02:21 PM

I redid my whole rear last year and went w/ Eaton, 3.42 gears, new axles, bearings, seals, etc. With labor and me pulling it out, it came to about $1250.

ChevyDude · 03-24-2005, 04:48 PM

I went EATON...just did it last week!

toddtheodd · 03-24-2005, 08:01 PM

So is the powertrax crap then? That is the feeling I'm getting whenever I read anything on it.

jamesi20 · 03-24-2005, 10:39 PM

I just had the Truetrac gear driven limited slip put in mine.the guy that did it talked me out of the eaton unit.I took his word on the function and durability of the truetrac because rearends are what he does for a living,only rear ends,and he is a NHRA national title holder to boot so I figured he knew what he was talking about.All together with buying one good used axle I got it with new bearings,3:73 ring and pinion,and the truetrac unit insalled and a couple of qts.of oil for 1000.00

minibike · 03-24-2005, 11:03 PM

I have the stock chevy posi, which I believe is an Eaton. Put $100 worth of clutches and parts into it and it was a direct replacement for the open diff. What I mean is...it was a 2 hour job swapping them out, because the same shims worked. I pulled the open diff out, keeping the shims on the correct sides, got the bearings off without damaging them, pressed them onto the rebuilt stock posi, and reinstalled with the same shims. Gear pattern was really good, and all went well. I have installed differentials with new ring and pinions, and it takes a long time to get it right, but if you are reusing your old ring and pinion and can salvage your old bearings, it is much easier. I have made a half dozen 14.1-14.5, 1/4 mile passes on it since the swap, and it is holding up fine.

CrazyCooter · 03-25-2005, 01:02 AM

That TrueTrac is a sweet unit!

I like them better that the Eaton and Auburn combined. All gears....no clutches to wear out.

I have one in the rear of my Samurai and front of my Chevy.

Can't beat Tractech's reputation either.

71Chevy4-speed · 03-25-2005, 02:32 PM

A buddy of mine as the truetrac, he's beat the living hell outta it and its to the point that most of the time it will only spin one tire, but it won't break lol.

chevy72blu · 03-25-2005, 04:15 PM

The Auburn unit will actually take a lot more stress than the Eaton.. but if it does break, you have to send it to Auburn to have the cones replaced

03-07-2005, 11:38 PM	#1
chevybill Senior Member Join Date: Oct 2004 Location: calhoun city ms Posts: 940	Opinions on posi traction differential I am asking for your opinions on which differential unit to buy and a source. So far, the best buy I have located is on an auburn posi pro unit from jegs. Powertrax and eaton are a couple of others I have ran across. The powertrax unit can be installed without removing the ring and pinion (according to jegs customer support). At this point I am probably going to have to run an automatic th 350 due to cost and I have a 3.73 gear in the rear end presently. I want to be able to tow with the truck, and would really prefer a 5 spd. manual tranny, but they are very expensive; even used from a salvage yard. So you thoughts on posi differentials and suppliers, please. Thanks to everyone __________________ ongoing 1970 c 10 lwb 1994 z-28 few mods.-owned since new 1978 vette silver/grey 25th anniv. paint

03-08-2005, 01:19 AM	#2
Low69CST Registered User Join Date: May 2000 Location: Frankfort, Kentucky, USA Posts: 2,163	The powertrax is a locker unit. It'll be more aggressive. That means you'll hear it locking unlocking. Your truck will knot up alot making sharp turns. But when you hit the gas, straight 1 to 1 ratio between your tires __________________ '69 CST Short fleetside Lowered, 400 small block, 700R4, 4 wheel disc brakes, front sway bar & rear camaro sway bar (in progress) '87 V10 4x4 Short Fleetside Quad Suspension and Dual Tanks

03-08-2005, 09:39 AM	#4
chevybill Senior Member Join Date: Oct 2004 Location: calhoun city ms Posts: 940	thanks for the replies, so far. based on the above description, I will probably move away from the powertrax unit, since it is a little more extreme. please, more opinions thanks __________________ ongoing 1970 c 10 lwb 1994 z-28 few mods.-owned since new 1978 vette silver/grey 25th anniv. paint

03-08-2005, 12:50 PM	#5
70c10 67-72 Addict! Join Date: Feb 2002 Location: The TAX State! Posts: 7,857	I got mine from Tom's diffs for $280 and have been happy with it. __________________ Jim 1970 C/10 Fleetside w/Ghost Flames Lowered 4.5" front and 4" rear (Raked) 355/350 Turbo w/shift kit 10" Redneck Performance Verter w/2500 stall Hooker Super Comps part#2808-1 Performer RPM Air-Gap 12 Bolt w/3:73 gears- Eaton Posi Comp Cams XE262 with 1.6 Crane Energizers, Road Demon 625 and Brodix IK 180 heads

03-08-2005, 02:55 PM	#6
Back in Black Registered User Join Date: Dec 2004 Location: Donnelly, MN Posts: 52	eaton unit I could be wrong but my mechanic said the Eaton limited slip for a 12 bolt truck is back ordered indefinitely. This could be for just the higher geared rear ends. I have a 3.07 posi with a bad carrier. The lowered geared models may be available.

03-08-2005, 09:03 AM	#3
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	My preference is the Eaton Posi. Here is a link to a source. Jim http://www.tomsdifferentials.com/tomp.htm

03-08-2005, 09:51 PM	#7
chevybill Senior Member Join Date: Oct 2004 Location: calhoun city ms Posts: 940	70 c10, how long ago did you purchase your unit, in summit their price is 449.95, are they tying to take people to the cleaners or what? __________________ ongoing 1970 c 10 lwb 1994 z-28 few mods.-owned since new 1978 vette silver/grey 25th anniv. paint

03-08-2005, 09:53 PM	#8
Dean23 68cst_ss490 Join Date: May 2001 Location: edmonton,canada Posts: 1,363	Id go with the eaton myself. At least you can reapir the eaton if needed. with the auburn once the clutch cones wear its pretty much just a throw away piece. __________________ Dean edmonton,canada a winter wonderland 2005 Chevrolet Avalanche LT cold air intake, performance exhaust, Comp cams cam, jba shorty ceramic headers. http://www.cardomain.com/ride/3090973

03-08-2005, 11:35 PM	#9
70c10 67-72 Addict! Join Date: Feb 2002 Location: The TAX State! Posts: 7,857	chevybill- my unit is 2 years old. I paid an additional $25 for bearings and races and about $25 shipping from California. I reused my 3:73's and my buddy charged $100 bucks for the swap which took 3 hours. I have about $450 invested in parts, shipping and labor. __________________ Jim 1970 C/10 Fleetside w/Ghost Flames Lowered 4.5" front and 4" rear (Raked) 355/350 Turbo w/shift kit 10" Redneck Performance Verter w/2500 stall Hooker Super Comps part#2808-1 Performer RPM Air-Gap 12 Bolt w/3:73 gears- Eaton Posi Comp Cams XE262 with 1.6 Crane Energizers, Road Demon 625 and Brodix IK 180 heads

03-08-2005, 11:48 PM	#10
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	the eaton is the better unit by far much more durable than the auburn and the powertrax like to blow apart under higher horsepower. toms differentials seems to have the best prices on the eaton posi unit __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

03-24-2005, 01:54 PM	#11
'70_402 Senior Member Join Date: Dec 2003 Location: Pampa, Texas Posts: 1,554	i called toms and they now offer thier eaton posi units for $336, but that is still cheaper than any i have found... __________________ https://www.ebay.com/itm/295742064443

03-24-2005, 02:21 PM	#12
boraxman Keepin an eye out Join Date: Feb 2003 Location: So.Cal Posts: 3,921	I redid my whole rear last year and went w/ Eaton, 3.42 gears, new axles, bearings, seals, etc. With labor and me pulling it out, it came to about $1250. __________________ 1970 Chevy C10 SWB 5.3 1996 Toyota Tacoma SR5 4x4 2007 Vespa GTS 250 Scooter ZIP 91351

03-24-2005, 04:48 PM	#13
ChevyDude Senior Member Join Date: Jun 2003 Location: Westminster, CO Posts: 3,071	I went EATON...just did it last week! __________________ Alex 1971 Lil' Red 350 SBC 700R4

03-24-2005, 08:01 PM	#14
toddtheodd The oddest Todd around Join Date: May 2004 Location: Miami, Florida Posts: 1,418	So is the powertrax crap then? That is the feeling I'm getting whenever I read anything on it. __________________ "The greatest pleasure is to vanquish your enemies and chase them before you, to rob them of their wealth and see those dear to them bathed in tears, to ride their horses and clasp to your bosom their wives and daughters." Ghengis Khan IIOY???

03-24-2005, 10:39 PM	#15
jamesi20 Senior Member Join Date: May 2002 Location: NORTHEAST OHIO Posts: 493	positraction I just had the Truetrac gear driven limited slip put in mine.the guy that did it talked me out of the eaton unit.I took his word on the function and durability of the truetrac because rearends are what he does for a living,only rear ends,and he is a NHRA national title holder to boot so I figured he knew what he was talking about.All together with buying one good used axle I got it with new bearings,3:73 ring and pinion,and the truetrac unit insalled and a couple of qts.of oil for 1000.00



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03-24-2005, 11:03 PM	#16
minibike Registered User Join Date: Jun 2002 Location: Lafayette, LA Posts: 500	I have the stock chevy posi, which I believe is an Eaton. Put $100 worth of clutches and parts into it and it was a direct replacement for the open diff. What I mean is...it was a 2 hour job swapping them out, because the same shims worked. I pulled the open diff out, keeping the shims on the correct sides, got the bearings off without damaging them, pressed them onto the rebuilt stock posi, and reinstalled with the same shims. Gear pattern was really good, and all went well. I have installed differentials with new ring and pinions, and it takes a long time to get it right, but if you are reusing your old ring and pinion and can salvage your old bearings, it is much easier. I have made a half dozen 14.1-14.5, 1/4 mile passes on it since the swap, and it is holding up fine. __________________ 69 SWB LT1/4L60E www.classicplace.com

03-25-2005, 01:02 AM	#17
CrazyCooter Registered User Join Date: Jan 2004 Location: Redding, CA Posts: 148	That TrueTrac is a sweet unit! I like them better that the Eaton and Auburn combined. All gears....no clutches to wear out. I have one in the rear of my Samurai and front of my Chevy. Can't beat Tractech's reputation either. __________________ 2006 Ram 3500 4x4 CTD 6 Speed 73 Chev K30 Flatbed 91 Jeep YJ 58 Jeep CJ5 See my pics: http://www.flickr.com/photos/18032714@N08/

03-25-2005, 02:32 PM	#18
71Chevy4-speed Speed Limit = Floorboard Join Date: Jan 2004 Location: Kasilof, Alaska Posts: 803	A buddy of mine as the truetrac, he's beat the living hell outta it and its to the point that most of the time it will only spin one tire, but it won't break lol. __________________ 1971 C20 350, 4-speed - Sold. 1985 K10 350, Built 700r4, Edel 1406, Performer intake, MSD Ign, Hooker Comps, Silverstars, Piaa drivers, LED tails, Toyo A/T 31's, Eaton Posi, the project. "Build for torque, horsepower will follow"

03-25-2005, 04:15 PM	#19
chevy72blu Registered User Join Date: Apr 2004 Location: Las Vegas, NV Posts: 2,188	The Auburn unit will actually take a lot more stress than the Eaton.. but if it does break, you have to send it to Auburn to have the cones replaced __________________ RIP EastSideLowLife '72 C20 SWB convert. 5 lug, LS1/4l60e

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