Page 1 of 2 12 LastLast
Results 1 to 20 of 24

Positraction

This is a discussion on Positraction within the Drivetrain forums, part of the LSx Technical Help Section category; Ok heres the quick scoop Got a 99 T/A... thought I had positraction... or what ever would have both tires ...

  1. #1
    Member Phlash_riot's Avatar
    Join Date
    Aug 2006
    Location
    San Diego
    Age
    38
    Posts
    397

    Midnight Blue
    1999 T/A

    Positraction

    Ok heres the quick scoop
    Got a 99 T/A... thought I had positraction... or what ever would have both tires turning and burning... recently found out that I have only one tire burning. Did a burnout only ONE mark on the road

    Then i was in some snow I open the drivers door and give a little gas and hear on tire turning and the other is sitting there staring at my like a 3 toed sloth... What gives......

    Do all T/As have posi and mines broken or is it an option.... and how do i get it in my T/A... I can't have this anymore one tire burning out... its sacrilegious!!!!!

  2. #2
    Formulatastic yellowv's Avatar
    Join Date
    Dec 2006
    Location
    S. Florida
    Age
    39
    Posts
    1,271

    Red
    98 Formula /93 Z28

    Quote Originally Posted by Phlash_riot View Post
    Ok heres the quick scoop
    Got a 99 T/A... thought I had positraction... or what ever would have both tires turning and burning... recently found out that I have only one tire burning. Did a burnout only ONE mark on the road

    Then i was in some snow I open the drivers door and give a little gas and hear on tire turning and the other is sitting there staring at my like a 3 toed sloth... What gives......

    Do all T/As have posi and mines broken or is it an option.... and how do i get it in my T/A... I can't have this anymore one tire burning out... its sacrilegious!!!!!
    Posi is a limited slip differential. It's not a locker. They both aren't gonna spin all the time. Hence the term positraction. The differential will apply more power to the wheel with more traction.

  3. #3
    Member Phlash_riot's Avatar
    Join Date
    Aug 2006
    Location
    San Diego
    Age
    38
    Posts
    397

    Midnight Blue
    1999 T/A

    i know how both work but that is not happening on mine... If one wheel is spinning an the other one is not then the wheel with mortraction is not getting any power otherwise it would spin as well... I belive that there are clutch discs in positraction so mabye the clutch went out on mine.

  4. #4
    Formulatastic yellowv's Avatar
    Join Date
    Dec 2006
    Location
    S. Florida
    Age
    39
    Posts
    1,271

    Red
    98 Formula /93 Z28

    The diff could be going but you were talking about spinning the tires in the snow. Will it only spin one on nice dry pavement as well?

  5. #5
    Member Phlash_riot's Avatar
    Join Date
    Aug 2006
    Location
    San Diego
    Age
    38
    Posts
    397

    Midnight Blue
    1999 T/A

    yes.


    i am making sue that posi is a standard feature too

  6. #6
    A trained professional volleybill's Avatar
    Join Date
    Dec 2005
    Location
    upstate NY
    Age
    63
    Posts
    95

    Black
    2001 Z28

    RPO G80, check your tag on the door

  7. #7
    Member Phlash_riot's Avatar
    Join Date
    Aug 2006
    Location
    San Diego
    Age
    38
    Posts
    397

    Midnight Blue
    1999 T/A

    Thanks I'll look into that today when its daylight out. So i take it that it is not a standard feature

  8. #8
    Member z28misfit's Avatar
    Join Date
    Jun 2006
    Location
    Fleetwood,Pennsylvania
    Age
    30
    Posts
    249

    Red
    1999 Chevy Camaro Z28

    As far as clutches go, you most likely have the Zexel Torsion unit. I believe all the LS1 f body's have them. They don't really have clutches, I believe they are called helical gears. Let me know if I'm wrong on this. But anyway, I would think as long as it's good, it should let 2 lines when you do burnouts. I know mine has never left one mark.
    99 z28 cam,m6 ,S60 4.56gears,Fast 90/90 full boltons,more mods one day.
    11.2 @ 123mph.

  9. #9
    The Bandit Wesman's Avatar
    Join Date
    Apr 2006
    Location
    NJ
    Posts
    4,033

    SGM
    1998 Trans Am WS6

    Quote Originally Posted by z28misfit View Post
    As far as clutches go, you most likely have the Zexel Torsion unit. I believe all the LS1 f body's have them. They don't really have clutches, I believe they are called helical gears. Let me know if I'm wrong on this. But anyway, I would think as long as it's good, it should let 2 lines when you do burnouts. I know mine has never left one mark.
    Many of the earlier LS1's, like 98-99's, had the Auburn Differentials. They are clutch pack equipped, limited slip units. After a while the clutches wear out, and only one wheel will spin when you are trying to get traction. You need to replace the carrier with a new unit in order to fix it. Ideally, a brand new Auburn will lay down 2 strips of rubber on a hard launch, so its a real posi.

    Later LS1's were equipped with the Zexel Torsen units, which, like you said, don't have clutches and therefore can't really "wear out". The performance of the Torsen, provided it isn't broken, will be consistant no matter how old it is. However, since it doesn't have clutches, it can only distribute torque to the wheel that has more traction, hence the name Torsen, or "Torque Sensing". So if even though both wheels will be getting torque, one will be getting more than the other at any given time. Hence, it may only lay down one strip of rubber on a hard launch. The other disadvantage to the Torsen is that if one wheel has no traction (ice/snow) the car won't move. Both wheels need to have at least some traction for the diff to work properly.

    As for determining which diff you have, perhaps someone else has some insight on that. I don't know how to specifially tell the difference between the two.

  10. #10
    Member z28misfit's Avatar
    Join Date
    Jun 2006
    Location
    Fleetwood,Pennsylvania
    Age
    30
    Posts
    249

    Red
    1999 Chevy Camaro Z28

    I know I have the Torsion model. I do know the LT1 cars have the Auburn.

  11. #11
    2004 HEAD/CAM CTS-V 9t8z28's Avatar
    Join Date
    Oct 2006
    Location
    doylestown, Pa
    Posts
    6,818

    SILVER
    2004 CTS-V

    93-98 Auburn
    96-97SS Torsen
    99-02 Torsen

  12. #12
    Member Phlash_riot's Avatar
    Join Date
    Aug 2006
    Location
    San Diego
    Age
    38
    Posts
    397

    Midnight Blue
    1999 T/A

    Well I still have yet to check out my RPO code but i everything above holds true looks like I have the Torsen unit.

    So here's the new question... I want a differential that spins both tires no matter what. ice snow burn outs i want both giving me traction. no the possibility of both. Wha shoudl i get? in a 10 bolt, I'm not swapping out to a 12bolt . soon as the new Camaros come out (and are avalible to get due to demand) i'm trading the bird in.

  13. #13
    The Bandit Wesman's Avatar
    Join Date
    Apr 2006
    Location
    NJ
    Posts
    4,033

    SGM
    1998 Trans Am WS6

    Quote Originally Posted by Phlash_riot View Post
    Well I still have yet to check out my RPO code but i everything above holds true looks like I have the Torsen unit.

    So here's the new question... I want a differential that spins both tires no matter what. ice snow burn outs i want both giving me traction. no the possibility of both. Wha shoudl i get? in a 10 bolt, I'm not swapping out to a 12bolt . soon as the new Camaros come out (and are avalible to get due to demand) i'm trading the bird in.
    Look into the Eaton Powertrax.

    JEGS's sells them, heres the link:

    http://www.jegs.com/webapp/wcs/store...44476_-1_10153

  14. #14
    Quote Originally Posted by 9t8z28 View Post
    93-98 Auburn
    96-97SS Torsen
    99-02 Torsen
    really the LT1 SS's got a different rear end then the 96-97 Z's?

  15. #15
    Moderator Firebirdjones's Avatar
    Join Date
    May 2006
    Location
    Arizona
    Posts
    12,552
    I think positraction has been misunderstood over the years,,,posi has always been what GM referred to as a clutch style unit, both wheels will spin all the time,,,unless for some reason the clutch pack is weak or worn.
    At some point in time, people started referring to positraction as a limited slip, or one wheel spinning most of the time. Simply not the case.
    Limited slip, positraction, both mean the same thing among most car enthusiasts, both refer to the clutch style unit that GM has used for years.
    In a slippy situation with one tire on ice or snow,,,technically a clutch style unit will pull you right out without spinning the one tire in the snow, utilizing the tire that is on the pavement, the tire in the snow cannot spin unless the power applied overcomes the clutch packs in the posi unit. Only then will the tire in the snow spin,,,,once this happens it puts some wear on the clutch packs,,,the more you do it,,,the more it wears. After a while the clutches are worn to a point where they are not that effective anymore. They are made to slip to some extent for turning obviously.
    You can check the condition of the clutch style posi unit,,,this comes right out of an old GM manual I have in the shop.
    Hold the pinion still with a prybar,,,I have a tool that bolts to the yoke. Using a torque wrench on one wheel,,,either side it doesn't matter,,,try to turn one wheel while holding the pinion still,,,sometimes this takes 2 people.
    GM has a torque reading specification,,,at the point in which you can break the clutch packs loose to turn one wheel while the other stays still. I don't remember the number off the top of my head,,,,but I can tell you a good posi unit will make you grunt and sweat trying to turn one wheel. If it's rather easy,,chances are,,,,the clutches are worn.
    You probably have the auburn style unit, which uses cones,,,these are not as durable, and when they are worn,,,generally they become a door stop. The cones wear into the case, and renders them useless. The case can be machined and the cones shimmed out,,but it's a bandaid.
    Go with the Eaton unit,,,clutch style,,they are rebuildable with various kits you can tailor the preload on the clutches to the point where there is virtually no slip at all, and can even chatter tires around corners if you like,,,these are what I use to get around in the snow and they work flawless,,,as long as I can get one rear tire on dry pavement,,,it will pull me right out of the snow without problems.
    As far as I know,,,,All T/A's came standard with posi,,,this is how it was back in the day throughout the 70's and I don't believe that has changed. Chances are you have a wornout unit and it's time for a replacement. Larry.

  16. #16
    Stang Reaper LS1Formula01's Avatar
    Join Date
    Nov 2006
    Location
    Missouri
    Age
    32
    Posts
    205

    Pewter Metallic (1of?)
    2001 Formula M6(1 of 225)

    Long story short, all LS1 F-bodies have the torsen diff, which has a worm gear design, torque and centrifical force cause the gears to climb up another set of gears to engage the axles, one always turns, the gears in the diff have to engage to turn the other. I notice on take offs where i ease into the power its hit or miss as far as one or both engaging in mine, now when i rev up and dump it, both engage and smoke like cheech and chong.

  17. #17
    2004 HEAD/CAM CTS-V 9t8z28's Avatar
    Join Date
    Oct 2006
    Location
    doylestown, Pa
    Posts
    6,818

    SILVER
    2004 CTS-V

    Quote Originally Posted by LS1Formula01 View Post
    Long story short, all LS1 F-bodies have the torsen diff, which has a worm gear design, torque and centrifical force cause the gears to climb up another set of gears to engage the axles, one always turns, the gears in the diff have to engage to turn the other. I notice on take offs where i ease into the power its hit or miss as far as one or both engaging in mine, now when i rev up and dump it, both engage and smoke like cheech and chong.
    98 did not come with Torsen!!!

  18. #18
    Stang Reaper LS1Formula01's Avatar
    Join Date
    Nov 2006
    Location
    Missouri
    Age
    32
    Posts
    205

    Pewter Metallic (1of?)
    2001 Formula M6(1 of 225)

    It was an option if i am not mistaken, buddy of mine has a 98 w/torsen. unless it was put in after the fact.

  19. #19
    Rollo Tomassee AKIRA's Avatar
    Join Date
    Aug 2005
    Location
    Outside the box
    Age
    37
    Posts
    2,887
    After going through my rear end bullshit, the differential I pulled out was a Torsen. We slid it onto an axel that was in a vice. My mechanic said that with one axle locked (in the vice), the differential shouldnt spin on the axle. It sure did.
    We put the Eaton on in place of the Torsen and we couldnt spin it.

    I didnt get the PowerTrax one but the Eaton (clutch based one). So far so good.

  20. #20
    2004 HEAD/CAM CTS-V 9t8z28's Avatar
    Join Date
    Oct 2006
    Location
    doylestown, Pa
    Posts
    6,818

    SILVER
    2004 CTS-V

    Quote Originally Posted by AKIRA View Post
    After going through my rear end bullshit, the differential I pulled out was a Torsen. We slid it onto an axel that was in a vice. My mechanic said that with one axle locked (in the vice), the differential shouldnt spin on the axle. It sure did.
    We put the Eaton on in place of the Torsen and we couldnt spin it.

    I didnt get the PowerTrax one but the Eaton (clutch based one). So far so good.
    What do you mean?

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. GTO Differential & Positraction Unit
    By NBM LS1 M6 in forum GTO
    Replies: 1
    Last Post: 08-19-2006, 02:05 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •