posi or lockers - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bad 71 chevy · 06-12-2002, 07:27 PM

This is the deal i have a 373 geras but no posi all i want to do is to be able to lay down 2 tire marks insted of 1
all so what would you pay for a posi or lockers thanks

JReynolds · 06-12-2002, 07:54 PM

I used a powertrax lock-rite in my '69 "Farm Truck"
It's got 3.07 rear end, I put 4 speed saginaw from Nova SS.
380 Horse/450Ft/Lb. I drove the truck once after the motor was in, without posi or locker, and knew right away that it wouldn't cut it. I chose the lock-rite because it's easy to install, only took about 1 hour. You don't touch the ring & pinion, so you don't need to know how to set up a rearend properly.
Disadvantages after driving it for several months are:
It does make the "chunk chunk chunk" noise that critics mention. This only happens when you are turning fairly sharply. If this noise will bother you, stay away from any type of driven plate type locker. (By the way they cost $300.00 from Summit)
Now I see that Powertrax has a new style that supposedly eliminated the noises that the lock rite makes, costs about $400.00. Anyway, the other thing about driving with this is that it is not permanently locked, so unless you do a burnout everytime you start, only 1 wheel is engaged, so if you have a manual trans, when you shift and let off the gas, you will feel the rearend "move" one way or the other, depending on which tire is engaged. Basically, cornering is a bit wierd with it. The website, WWW.powertrax.com explains things better than I do. My truck is strictly for fun, so I don't mind these quirks. If it were a daily driver, or my wife were going to drive it, I would spend the bucks for a truue posi. My 2 cents worth..............

Mountain Man · 06-12-2002, 08:46 PM

I just had an Auburn posi put in my truck.

It works very well, and disengages in corners, so is silent.

It is not a cheap set up at 1600 canadian for the auburn posi unit, new ring and pinion ( which you probably don't need), new bearings, seals, etc.

A good third member is critical to a good power train.

runx68SWB · 06-12-2002, 09:17 PM

i have also installed an auburn pro limited slip in my 68 swb and have been very pleased with it.... very quiet.... very responsive.... will certainly give you those 2 tire burnouts you seek.... so much better than a peg leg LOL one other thing.... i made the mistake of putting trans x limited slip in the differential when i was first breaking it in.... this is a big no no.... my brand new posi unit was locking up and not disengaging after a week.... i immediately drained it and put GM limited slip additive in there and have been a happy camper since

DeepPurple · 06-12-2002, 10:43 PM

Hi Bad,

Personally, I use the Powertrax "No-Slip " system that JR referred to earlier. It is a great improvement as it makes little to no noise/chattering when engaging/disengaging and it doesn't lock upm so tight that the tires chirp going around the corner unless you're near the steering lock.
What I really like about it is it lets the former "no-snow-go" become an artic cat, and yes it allows you to let down two strips of rubber. And to top it all off, all one has to do is remove the spider gears and follow the directions.
In other words, I highly recommend it, even at $400.

Low69CST · 06-12-2002, 10:56 PM

Lockers are very rugged. Used mainly for rock crawling, racing and serious street situations. A locker is basically like having a spool in your truck, that disengages when you let off the gas. Anytime your foot is on the gas both rear tires are turning the exact same speed. Even if your in a turn each tire will turn the same speeds, meaning your truck will bind a little and your tires will squeel a little in turns. But also both tires will turn with full engine force.

With a posi, most are clutch driven. That means one tire will have 100% engine force, but the other one may be recieving as little as no power or as much as 100% power. So a posi rear end may not lay 2 strips of rubber every time you spin your tires.

I picked a locker because I'm sure i'm gonna have traction problems. 4.10 gears with 3.06 tranny 1st gear. Plus a 450lb/ft engine. I also drive pretty rough sometimes. My truck is also built pretty racy, so i t hought that would fit better than a posi. When it locks up it hits pretty loud, which I think is cool, my dad has other thoughts.

Either can be good or bad, like i've said a million times, it all depends on what you want out of your truck.

JReynolds · 06-12-2002, 10:59 PM

D.P. that makes me jealous. I wish I had sprung for the extra $100.00 when I bought mine. So it actually does what they say as far as being quiet & smooth? That is sweet, and I really don't see a reason for someone to spend $800.00 for a posi & setup any more.

Mike C · 06-12-2002, 11:52 PM

Guys who have put lots of power into the powertrax find they unlock right when you need them the most. The Auburn has cone type clutches that "bite" into the case, wearing both out. Lockers belong in the dirt IMO and limited slips on the street, but for my money I'd run an Eaton rebuildable positraction unit. I've been looking for a used limited slip from an 87-89 300ZX turbo for over 2 years for my Z. They run over $500 used. A new one is $550 IF they'll ever get them in stock. So consider all of your options a blessing!

1971LT1SWBPOSI373 · 06-13-2002, 07:50 AM

I put a powertrax unit into my rear with new richmond 3:73 gears... I haven't run the unit to know if I like it yet, but it was easy to install and didn't gouge into my pocket book too deep. Summit Racing only had good things to say about it, and I had confidence in their feedback, after all.... they are the racing people. I noticed a definate clicking sound when cornering, but if my girlfriend were in the truck with me, I probably wouldn't hear a thing at all..............

BadAzz70PU · 06-13-2002, 08:09 AM

I have the powertrax locker also and I am very happy with it. It always locks when you want it to and as Low69CST said, it always locks under power, which could mean in a turn. The only time I can hear mine making the clicking noise is if my window is down and my head is hanging out, other than that, its quiet in the cab.

It does take a little time to get used to its characteristics but I do like it a lot and you cant beat the ease of install or price, mine also is from Summit.

MOTHERTRUCKERS · 06-13-2002, 08:28 AM

I have 1 new powertrax unit left in my display case 350.00 + shipping if anybody is interested e-mail me.

Beast388 · 06-13-2002, 11:00 AM

I have an Auburn limited-slip in my Suburban. I would not recommend them to anyone. Mine works as it should, it is just extremely noisy after the rearend gets warm. It pops and grinds and is very unnerving. I have been religious about changing fluid and adding additive. If I were to do it all over again, I would install an Eaton.

Mike C · 06-13-2002, 04:01 PM

Hey Beast, Weren't you a guinea pig on the Powertrax also? I wish everyone could be persuaded the Eaton was the Shtuff. That's why GM ran them to begin with...

HvyChevy454 · 06-13-2002, 04:12 PM

same thing w/ my auburn posi it is very loud when cornering slow, it makes the real loud popping noise but i was told it would and it doesnt really bother me, i like to know its there.

Beast388 · 06-13-2002, 04:27 PM

Nope.....I've never tried a Powertrax. I don't think I ever will. They just don't inspire alot of confidence in my book.
In the Dana 60 rear that I am building I will be installing a Powr-Lok.

Sierra · 06-13-2002, 07:35 PM

I had an Eaton Posi installed last September, and that was probably one of my best investments. You don't even know it's there until you look in the mirror. No noise at all, even around corners, except for the squall of both tires. The Eaton is really smooth and effective, especially with the new carbon friction discs, not to mention rebuildable. It'll run you about $400 plus installation, but also leave you grinnin' ear-to-ear!

06-12-2002, 07:27 PM	#1
bad 71 chevy Registered User Join Date: Jun 2000 Location: Omaha NE 68122 Posts: 637	posi or lockers This is the deal i have a 373 geras but no posi all i want to do is to be able to lay down 2 tire marks insted of 1 all so what would you pay for a posi or lockers thanks __________________ 71 Chevy C/10 lwb 350 5 speed nv3500 3.73 rear end 2.5" Front Drop and 4" in the back Edelbrock perfomer rpm manifold Edelbrock 600 cfm carb Headmen headers

06-12-2002, 07:54 PM	#2
JReynolds Registered User Join Date: Jan 2001 Posts: 44	For me......Locker I used a powertrax lock-rite in my '69 "Farm Truck" It's got 3.07 rear end, I put 4 speed saginaw from Nova SS. 380 Horse/450Ft/Lb. I drove the truck once after the motor was in, without posi or locker, and knew right away that it wouldn't cut it. I chose the lock-rite because it's easy to install, only took about 1 hour. You don't touch the ring & pinion, so you don't need to know how to set up a rearend properly. Disadvantages after driving it for several months are: It does make the "chunk chunk chunk" noise that critics mention. This only happens when you are turning fairly sharply. If this noise will bother you, stay away from any type of driven plate type locker. (By the way they cost $300.00 from Summit) Now I see that Powertrax has a new style that supposedly eliminated the noises that the lock rite makes, costs about $400.00. Anyway, the other thing about driving with this is that it is not permanently locked, so unless you do a burnout everytime you start, only 1 wheel is engaged, so if you have a manual trans, when you shift and let off the gas, you will feel the rearend "move" one way or the other, depending on which tire is engaged. Basically, cornering is a bit wierd with it. The website, WWW.powertrax.com explains things better than I do. My truck is strictly for fun, so I don't mind these quirks. If it were a daily driver, or my wife were going to drive it, I would spend the bucks for a truue posi. My 2 cents worth.............. Attached Images __________________ 1969 SWB Stepside. 350 w/Vortec heads, 380 H.P., 450 ft/lb dyno proven.

06-12-2002, 08:46 PM	#3
Mountain Man Registered User Join Date: Jan 2002 Location: Calgary, Alberta, Canada Posts: 451	I just had an Auburn posi put in my truck. It works very well, and disengages in corners, so is silent. It is not a cheap set up at 1600 canadian for the auburn posi unit, new ring and pinion ( which you probably don't need), new bearings, seals, etc. A good third member is critical to a good power train. __________________ 72 C10 Cheyenne Super Full trim Factory tach dash A/C dash Factory tilt 350 / 350 power train - with Edelbrock components.

06-12-2002, 10:43 PM	#5
DeepPurple Real Deep... Join Date: Jun 2002 Location: St. Louis Posts: 116	Hi Bad, Personally, I use the Powertrax "No-Slip " system that JR referred to earlier. It is a great improvement as it makes little to no noise/chattering when engaging/disengaging and it doesn't lock upm so tight that the tires chirp going around the corner unless you're near the steering lock. What I really like about it is it lets the former "no-snow-go" become an artic cat, and yes it allows you to let down two strips of rubber. And to top it all off, all one has to do is remove the spider gears and follow the directions. In other words, I highly recommend it, even at $400. __________________ 1970 GMC C10 (Deep Purple) 383/700-R4 Mass Modifications 1976 GMC K5 Jimmy (Big Blue) 400/TH350 Coming soon to a drive-in near you... We have done So Much with So Little for So Long.. We are now qualified to do Anything with Nothing.

06-12-2002, 10:56 PM	#6
Low69CST Registered User Join Date: May 2000 Location: Frankfort, Kentucky, USA Posts: 2,163	Lockers are very rugged. Used mainly for rock crawling, racing and serious street situations. A locker is basically like having a spool in your truck, that disengages when you let off the gas. Anytime your foot is on the gas both rear tires are turning the exact same speed. Even if your in a turn each tire will turn the same speeds, meaning your truck will bind a little and your tires will squeel a little in turns. But also both tires will turn with full engine force. With a posi, most are clutch driven. That means one tire will have 100% engine force, but the other one may be recieving as little as no power or as much as 100% power. So a posi rear end may not lay 2 strips of rubber every time you spin your tires. I picked a locker because I'm sure i'm gonna have traction problems. 4.10 gears with 3.06 tranny 1st gear. Plus a 450lb/ft engine. I also drive pretty rough sometimes. My truck is also built pretty racy, so i t hought that would fit better than a posi. When it locks up it hits pretty loud, which I think is cool, my dad has other thoughts. Either can be good or bad, like i've said a million times, it all depends on what you want out of your truck. __________________ '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

06-12-2002, 09:17 PM	#4
runx68SWB Registered User Join Date: May 2002 Location: pueblo, Co Posts: 31	i have also installed an auburn pro limited slip in my 68 swb and have been very pleased with it.... very quiet.... very responsive.... will certainly give you those 2 tire burnouts you seek.... so much better than a peg leg LOL one other thing.... i made the mistake of putting trans x limited slip in the differential when i was first breaking it in.... this is a big no no.... my brand new posi unit was locking up and not disengaging after a week.... i immediately drained it and put GM limited slip additive in there and have been a happy camper since

06-12-2002, 10:59 PM	#7
JReynolds Registered User Join Date: Jan 2001 Posts: 44	Lock Rite part 2 D.P. that makes me jealous. I wish I had sprung for the extra $100.00 when I bought mine. So it actually does what they say as far as being quiet & smooth? That is sweet, and I really don't see a reason for someone to spend $800.00 for a posi & setup any more. __________________ 1969 SWB Stepside. 350 w/Vortec heads, 380 H.P., 450 ft/lb dyno proven.

06-12-2002, 11:52 PM	#8
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,723	Guys who have put lots of power into the powertrax find they unlock right when you need them the most. The Auburn has cone type clutches that "bite" into the case, wearing both out. Lockers belong in the dirt IMO and limited slips on the street, but for my money I'd run an Eaton rebuildable positraction unit. I've been looking for a used limited slip from an 87-89 300ZX turbo for over 2 years for my Z. They run over $500 used. A new one is $550 IF they'll ever get them in stock. So consider all of your options a blessing! __________________ 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

06-13-2002, 07:50 AM	#9
1971LT1SWBPOSI373 Registered User Join Date: Mar 2002 Location: Springfield, VA Posts: 460	I put a powertrax unit into my rear with new richmond 3:73 gears... I haven't run the unit to know if I like it yet, but it was easy to install and didn't gouge into my pocket book too deep. Summit Racing only had good things to say about it, and I had confidence in their feedback, after all.... they are the racing people. I noticed a definate clicking sound when cornering, but if my girlfriend were in the truck with me, I probably wouldn't hear a thing at all.............. __________________ 1971 Shortbed 350/350 w/ Posi-traction 3:73's 1996 Chevy Silverado TJ in Springfield, Virginia Likes old Chevy trucks Drinks Miller MGD

06-13-2002, 08:09 AM	#10
BadAzz70PU Long Lost Member Join Date: Dec 2000 Location: Clemson SC/ Langhorne Pa Posts: 1,183	I have the powertrax locker also and I am very happy with it. It always locks when you want it to and as Low69CST said, it always locks under power, which could mean in a turn. The only time I can hear mine making the clicking noise is if my window is down and my head is hanging out, other than that, its quiet in the cab. It does take a little time to get used to its characteristics but I do like it a lot and you cant beat the ease of install or price, mine also is from Summit. __________________ Tony 1970 C10 LWB -14.09 @ 96mph Web Site 1995 Eclipse GSX -15.46 @ 88mph (stock, not for long) College student at Clemson (SC) Home in Langhorne Pa

06-13-2002, 08:28 AM	#11
MOTHERTRUCKERS Registered User Join Date: Dec 1999 Location: BRADENTON FLA Posts: 3,269	I have 1 new powertrax unit left in my display case 350.00 + shipping if anybody is interested e-mail me. __________________ Rest in Peace Ed. Thanks for all the good times.

06-13-2002, 11:00 AM	#12
Beast388 Suburbans RULE! Join Date: Jan 2000 Location: Clinton, IA 52732 Posts: 689	I have an Auburn limited-slip in my Suburban. I would not recommend them to anyone. Mine works as it should, it is just extremely noisy after the rearend gets warm. It pops and grinds and is very unnerving. I have been religious about changing fluid and adding additive. If I were to do it all over again, I would install an Eaton. __________________ --Ben 71 GMC Suburban 4X4 The "Beast" 388 CID Stroker, TH350, NP205, 8-lug D44, 14BFF w/ Detroit, 4.10:1 gears, 4-Wheel Disks 4" Lift, 35" MT/R's.

06-13-2002, 04:01 PM	#13
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,723	Hey Beast, Weren't you a guinea pig on the Powertrax also? I wish everyone could be persuaded the Eaton was the Shtuff. That's why GM ran them to begin with...

06-13-2002, 04:12 PM	#14
HvyChevy454 Slowly getting CRSS... Join Date: Jul 2001 Location: Lutz, Florida Posts: 656	same thing w/ my auburn posi it is very loud when cornering slow, it makes the real loud popping noise but i was told it would and it doesnt really bother me, i like to know its there. __________________ -Nic Lutz, Fl My Team Website The Heavy Chevy Website ------------------ 72 Cheyenne 10 LWB GM 12-bolt 3.08 w/ Auburn Posi 91 454 Edel Performer RPM Intake 750 cfm carb Comp Cam 268/.495 Hedman Headers Dual 3'' Exhaust 71 Cheyenne 20 4x4 Fact. A/C PS PB Tilt Currently in the works... Speak Softly and Carry A Big Block... There is No replacement for Displacement... "If everything seems under control, you're just not going fast enough." - Mario Andretti

06-13-2002, 04:27 PM	#15
Beast388 Suburbans RULE! Join Date: Jan 2000 Location: Clinton, IA 52732 Posts: 689	Nope.....I've never tried a Powertrax. I don't think I ever will. They just don't inspire alot of confidence in my book. In the Dana 60 rear that I am building I will be installing a Powr-Lok. __________________ --Ben 71 GMC Suburban 4X4 The "Beast" 388 CID Stroker, TH350, NP205, 8-lug D44, 14BFF w/ Detroit, 4.10:1 gears, 4-Wheel Disks 4" Lift, 35" MT/R's.



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06-13-2002, 07:35 PM	#16
Sierra Registered User Join Date: Nov 2000 Location: Victoria, Texas Posts: 71	I had an Eaton Posi installed last September, and that was probably one of my best investments. You don't even know it's there until you look in the mirror. No noise at all, even around corners, except for the squall of both tires. The Eaton is really smooth and effective, especially with the new carbon friction discs, not to mention rebuildable. It'll run you about $400 plus installation, but also leave you grinnin' ear-to-ear!

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