non posi rear made into a pseudo posi rear

Discussion in 'Got gears?' started by scott kerns, Sep 20, 2009.

  1. scott kerns

    scott kerns Silver Level contributor

    ok here's an odd question that my memory conjured up from years past. I remember my buddy back in the 80's talking about taking a non posi rear and making both wheels turn by welding something. I'm fairly sure I won't be doing this, but will more than likely will replace rear when the funds permit. What could you do to make this happen?
     
  2. BUICKRAT

    BUICKRAT Got any treats?

    Yup, weld the side gears to the carrier. Takes special rod and you gotta warm the carrier before welding. I have a welded 12 bolt that I have been trying to break for a number of years but it wont. FYI, a welded rear is kinda hairy on the street, but you wont get a straighter launch.
     
  3. DaWildcat

    DaWildcat Platinum Level Contributor

    Been there, done that, broke it multiple times, almost killed myself when I was hanging my foot in it on a highway entrance ramp when second gear hit. Can you say "instant 360 spin out"?

    If you ask me it's definitely not the way to go.

    Devon
     
  4. techg8

    techg8 The BS GS

    I would think you could weld the spider and side gears together and achieve the desired result.
     
  5. CameoInvicta

    CameoInvicta Well-Known Member

    People always say this about welded rears and spools, and I have no idea why. I've driven high horsepower spooled cars on the street and haven't had anything remotely bad happen. They suck when trying to make a tight corner, but that's it.

    If it's your only option I say go for it.
     
  6. DaWildcat

    DaWildcat Platinum Level Contributor

    Andy, when you finally do wipe out on an entrance ramp, you'll be in the club and will sing a different tune, that's all.

    I'd be a moron if I said "I almost crashed my car because of the locked rear end, but I say go for it!".

    Devon
     
  7. CameoInvicta

    CameoInvicta Well-Known Member

    Ok Devon, I'll let you know. I'll be driving my Uncle's spooled '68 Charger in about two weeks. We'll see how it goes :Brow: :Brow: ...
     
  8. DaWildcat

    DaWildcat Platinum Level Contributor

    :TU:

    A light rain and trying to show off is what did me in that time, and trying to parallel park with tires squeeking the entire time turned off my date another time. I didn't marry her, so all the better!

    Since those days, I learned a lot more about brake systems engineering and how a locked rear axle can be a huge safety issue during hard braking while cornering or maneuvering, causing unexpected behavior of the tail end.

    Devon
     
  9. CameoInvicta

    CameoInvicta Well-Known Member

    Hey, you never said anything about rain :pp !

    In all seriousness, in any inclement weather a spool is asking for trouble. I would think it would be acceptable for most classics since they are rarely driven if the sun isn't shining.

    Making a tight turn in my Uncle's '68 about rattles your brain, the whole damn car shakes!
     
  10. wkillgs

    wkillgs Gold Level Contributor

    I would take Devon's advise!
    When a car goes around a turn, the outside tire travels a further distance than the inside tire....the purpose of a differential is to allow that to happen without losing much traction.
    With a welded carrier, one of the tires has to completely slip....or both tires will slip slightly. The result will be loss of traction and could be disastrous!!
     
  11. DaWildcat

    DaWildcat Platinum Level Contributor

    The problem with a locked axle is that it automatically creates a condition we call "split mu". mu (μ) is the Greek letter we geeks use for coefficient of friction.

    With braking system design, split mu is a condition in which tires are seeing different surfaces; say ice on the right, dry road on the left. Obviously, with a basic non-ABS system you panic stop in a situation like that, the left grips, the right slides and you get to go for a spin, literally!

    Driving the locked rear axle is creating a split mu on the left/right of the car's backside, right off the bat. Even during a gentle curve; at coast, both rear tires in a turn will lose traction. Acceleration and deceleration will alternate the traction loss from one side to the other, due to the driveline's load toward one side or the other.

    Please cruise at slow speeds with the locked rear axle. Please don't push it when the rest of us are on the streets with you.

    Devon
     
  12. alrobjr

    alrobjr big papa

    Is It Hard Work To Install A Mini Spool In A 10 Bolt 7
    5 Rear End? I Need Pictures Or Instructions If Its Not To Hard.
     
  13. monzaz

    monzaz Jim

    Ok here is something everyone is over looking. Spooling a rear usually requires aftermarket axles as you will tend to tear up the normal stock casting axle shafts...just not made for that kind of torsion stress. The heavier the vehicle the worse the twist on the axle in the corner before the tire slips.

    I would say if you had enough money to buy the car you should have enough to upgrade the rear engine and or trans correctly. You are not only endangering yourself but do think about other on the road when you go out of control with out a clue what direction your car will wipe out in.

    This is what separates us from ANIMALS... a brain that can reason. We have choices be it good or bad. Make your choice and live with it...set some money aside for the LAW SUITE TOO. :)

    Good luck and just ask I can help with price for the V8 buick members.
     
  14. BrianTrick

    BrianTrick Brian Trick

    Welding the spider gears might work for the dirt track guys,but I would not suggest it for a street/strip car.Yes,it is the same effect as a spool,but an open carrier does not have a thick enough body to withstand the added stress,& you can actually split or break the carrier in half.This would be the same effect/result if you installed a mini-spool into an open carrier.That is why all of your mini-spool manufacturers have a note stating "not intended for drag race use".
     
  15. BUICKRAT

    BUICKRAT Got any treats?

    The biggest problem I have with a welded rear is when you step on it, the car goes in the direction the REAR wheel are pointing...the steering wheel is essentially useless. A couple inadvertent lane changes on the highway taught me that. (dry pavement too).
     
  16. Cali72's

    Cali72's Well-Known Member

    Welding the spiders is dangerous and annoying!Have the tires chirping on every turn!When I went through the manual trans and differntial class my teacher had us weld gears on a 72 c 10 so we could see what the hell happens.You can find a good posi unit on this site where i got mine!:TU:
     

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