2004r Required upgrades?

Discussion in 'The "Juice Box"' started by hunter7389, Oct 28, 2018.

  1. hunter7389

    hunter7389 Well-Known Member

    The time has come to start getting ready to swap my TH400 for a 2004R. I received the 2004r with the car, and have zero history on it, other than it is obviously freshly rebuilt, and came from a Oldsmobile. What needs done to get it to hold up to my mild 455 in a street driven 69 Skylark? The car will likely never see anything close to a drag radial, but does have a set of 3.55's and an Eaton Posi on the shelf for the chevy 12-bolt.

    Is there a good site to read up on them?
  2. TexasT

    TexasT Texas, where are you from

    The trans section over on www.turbobuick.com has a plethora of 2004r info. You kinda have to sort through though I believe they got the search feature working over there.

    Getting the tv cable and bracket(s) installed and adjusted correctly will go a long way towards keeping the trans alive. The pump is designed to be variable pressure and the tv cable and valve in the valve body is how the pressure is signaled to rise as the throttle is opened. That pressure is how the clutches and band are applied and kept from slipping. Slipping makes heat and wear, and this "burns" the trans up.

    What "code" is the little plate on the tail end of the trans? Now that someone has been "inside" there could have been changes. But it does tell you what it was from the factory.
  3. techg8

    techg8 The BS GS

    If you're looking at a rebuild and performance recalibration, CK Performance kit "C" is what you need.


    Chris (owner) is a good guy and very helpful. Give him a call and tell him your plans. He won't steer you wrong.
    sailbrd likes this.
  4. sailbrd

    sailbrd Well-Known Member

    On mine we added the billet forward drum because of the tendency to twist the splines of the shaft. But you never know the one we took out was fine (keeping it as known good part!) Also makes a difference as to what trans you start with. Best are the BRF of CZ code transmissions. If you cannot find one of those you may need the valve body from extreme automatics: http://extremeautomatics.com/productdetail.php?product=112&fromc=21&fromt= Either CK or Extreme are great sources for parts or full transmissions. I think my last build ran about $1800 (by a friend of mine) and lives behind a supercharged 462. There may be some really good local builders depending on your location but I would not trust most builders on these transmissions.
  5. cruzn57

    cruzn57 cruzn57

    alot of what you will NEED INSIDE the 2004r, will depend on your driving,
    if you are rough with it, you need good internals,
    I have a stock 2004r in my 72/455, and it works great, but, it has 2.56 gears, so even the thought of stepping on it, makes me laugh, if you drag race, or street light race, upgrade it, or you WILL regret it,
    good hard parts , from Lonnie @ Extreme, or Chris @CK, will cost you easily $1000, plus a converter,
    STAY WITH LOCK UP, do not let anyone talk you into non lock,
    the best feature about a 2004r is higher stall conv, and lock up.
    sailbrd likes this.

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