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Pontiac Slim Jim won't disengage

Discussion in 'The Hokey Ass Message Board' started by GassersGarage, Sep 29, 2011.

  1. GassersGarage
    Joined: Jul 1, 2007
    Posts: 4,729

    GassersGarage
    Member

    I just picked up a '63 Grand Prix. Yesterday, every time I slowed to a stop, the engine died. It seems the trans won't disenagage and kills the motor. This was verified by jacking up the rear end and placing the trans in drive, the motor would stay running. On the ground, when placed in drive, the motor dies. Any ideas on what would cause this?

    I ran a search on the slim jim transmissions and the comments seem to be to switch to a 350/400 trans.
     
  2. G V Gordon
    Joined: Oct 29, 2002
    Posts: 5,683

    G V Gordon
    Member
    from Enid OK

    It is an adjustment. My '63 was doing the thing. I would have to manualy put it in neutral when coming to a stop. If you can get an old Motors or Chilton book it should show how to adjust the linkage. I'll look in mine and see if I can find it.

    When coming to a stop can you slip it into neutral manualy and not have it die?

    My slim jim served me well for 5+ years before i sold the car.
     
  3. GassersGarage
    Joined: Jul 1, 2007
    Posts: 4,729

    GassersGarage
    Member

    Yeah, if I slip it into neutral, it won't die. Thanks for the info, I'll check it. Fortunately, the car came with a shop manual. I was told the trans only had 3000 miles on it. No one I know, knows anything about those transmissions.
     
  4. G V Gordon
    Joined: Oct 29, 2002
    Posts: 5,683

    G V Gordon
    Member
    from Enid OK

    Everything can be adjusted from the topside where the transmission kickdown is on the throttle linkage.
     
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  5. if it's done right it will last 50,000-80,000 miles or so before it blows out. That's when most of them seemed to die, the one I had had about 71,000 miles on it when it hit the junkyard - it lasted long enough to have the quarters badly redone.
     
  6. GassersGarage
    Joined: Jul 1, 2007
    Posts: 4,729

    GassersGarage
    Member

    Well, the adjustment didn't work. Pulled the trans and she is at the shop. Broken ears on several clutch discs found, lots of clutch material found floating around. Supposedly the trans was rebuilt 3K miles ago.
     
  7. Camm
    Joined: Sep 22, 2005
    Posts: 590

    Camm
    Member

    That sucks. Rick, I like your Pontiac. Very clean car.
     
  8. Problem with these is they weren't around long and a lot of cars just got parked when they went bad, so finding someone that really knows them won't be easy. Could be the rebuilder made a mistake.
     
  9. I'd pull the motor and silde a newer 65-74 Pontiac motor in there with the Turbo 400...
     
  10. DE SOTO
    Joined: Jan 20, 2006
    Posts: 3,857

    DE SOTO
    Member

    Thats statement is as as Stupid as " I'd pull the Motor & put in a Chevy 350"

    If the Slim Jim turns out to be Junk, Locate the 4spd Hydra-Matic to replace it.

    Tranny Jon out in Riverside knows how to Fix them Old Hydra's & even Hop them up some.
     
  11. Trouble with going to the 4-speed hydro is it doesn't fit. They actually have a different floorpan with a lower trans tunnel in the shorter wheelbase full size Pontiacs for these years (Catalina and Gran Prix anyhow). Having had a Slim-Jim out on the ground, you might even have to clearance it a bit to fit a TH350/400/700R4/et all. Which is a pain in the ass on a car like a 'Prix most of which had a floor console.


    And, it's just as hard to find a guy who knows them enough to build one right.


    But rather than a motor swap on a perfectly good 389 I'd scare up an adapter, chuck a 200R4 in there, and call it done. It just needs to be something that will let you bolt a starter in place.
     
  12. GassersGarage
    Joined: Jul 1, 2007
    Posts: 4,729

    GassersGarage
    Member

    I'm waiting to hear back from the trans shop to see if it can be rebuilt.
     
  13. Spend 1500-2000 for a rebuilt piece of shit? What a fucken asshole..:rolleyes:

    Listen mommys boy, I was modifying hydros when you were swimming in your old mans balls, the Roto and the Dual Coupling hydro work best on the back of a scrap truck...
     
  14. The 200r4 might be a good choice.. You might not need to modify the trans tunnel for it..

    When I swapped my Dual Coupling hydro for my Turbo 400 it fit perfectly.. Of course the Bonneville/Star Chief has a bigger trans tunnel.. I know of a couple guys who did the th-400 swap into there Catalina's and didn't have to cut anything, however most do have to cut. May be some Catalina/GPs came with the Bonneville floor,I don't know...
     
  15. DE SOTO
    Joined: Jan 20, 2006
    Posts: 3,857

    DE SOTO
    Member


    Who Gives a Fuck what you were doing a 100 yaers ago Shit Breath.

    I have run these Trannys with Very good Results.

    Guy's like you are what is Screwing up the Old Original Style cars.

    Your sugestion would cost the Guy way more than 2 grand to do the swap Right ...

    Stop hiding as a Guest & Man up to a Member ... OR SCRAM !
     
  16. TININDN
    Joined: Nov 24, 2008
    Posts: 16

    TININDN
    Member Emeritus
    from Minnesota

    A good rebuilt slim jim is a good trans, provided the rebuilder knows what he's doing an uses good parts. I had jim rebuilt in my '63 8 years ago, have driven the car thousands of miles including several long distance trips. Only issue was a failed aftermarket damper plate (watch that) replaced in route to Phoenix from Minneapolis by three of us old timers with the help of a couple of young guys at a two-man transmission shop. They couldn't believe it when we pulled the trans - what - no converter? Had to borrow a pick-up and drive 200 miles round-trip get two used slim jims for parts, off the road at 10:30 AM - back on the road at 8:30 PM with a front pump (damaged by the failed damper plate) and a used damper plate installed. That used damper plate now has about 15K on it with no issues.

    I agree - to swap to a TH400 is at least 2K to do it right -
     

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