Hello, Allpar Forums member or visitor! If you were a member, you would not see this ad!

Register or log in at the top right of the page...

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Stall converter wear on drive hub

Discussion in 'A Body: Duster, Valiant, Dart, etc' started by core, Oct 21, 2015.

  1. dana44

    Ad-Free Member

    Joined:
    Jun 17, 2002
    Messages:
    19,326
    Likes:
    1,238
    It could have been that way from the beginning, or possibly the block was line bored and moved the crankshaft position moved. I have seen taper bored cylinders so that they are perfect after 100,000 miles of wear and the ridge at the top removed, preventing a bore job after the fact, decks of blocks off by a tenth of an inch from front to rear, bolt holes drilled all the way through to water and oil passages. Things happen one does not expect in a repeated machining process, but it happens. It could also, in your case, be the transmission case itself, the pilot holes could be slightly off instead of the block itself being off. Remember, in a case like this, if you think about the center of a wheel with spokes that go straight out from the center, a small center position off increases as you go outward, so something that is .010 off center in the middle, ten inches outward requires .035inches correction, as an example. We don't expect these kinds of errors, and usually don't think to check them because they were fine before we tore them apart, but they happen on occasion. I'm just glad you got it fixed.
     
  2. core

    core Member

    Joined:
    Nov 1, 2012
    Messages:
    130
    Likes:
    1
    After I posted this morning I went to go for a moring drive. Pulled the valiant out of the barn and noticed tranny flued on the floor. The leak is coming from the same place at the pump seal. I've only driven the car for maybe 40 miles since it came from the shop.
    I am completely stumped by this problem. I spoke with the transmission mechanic and he's also baffled.
    I have no clue what to look for next. Ive gone through 2- transmission cases, 6- new stall converters, 2- flex plates and 2- different type of dowel pins.
    The block has been checked for runout and alinment.
    I've been hearing some bad feedback on the guy who built the motor. Is there anything he could have done to cause this problem?
     
  3. dana44

    Ad-Free Member

    Joined:
    Jun 17, 2002
    Messages:
    19,326
    Likes:
    1,238
    Well, if the front pump/converter seal has been changed, along with all your other changes, other than what I noted with the line boring, the dowel pin changes and adjustment should have accounted for that possible mis-alignment.
    Now, in reading your changes, you mention two transmission cases, but what about the front pump itself? And this is the seal you should have changed, too, right? Sure there isn't a crack or leak at the front pump itself, that it is actually coming from the front seal? Front pump of the transmission can only go on one direction and the vent is at the top with a plate that a bolt holds it into place on either side, about three inches or so long. Pretty much impossible for this to leak unless overfilled, but this would show on the dipstick as being really high (when pulled cold, not running, after sitting), that possibly the transmission cooler is draining back to the case, but this takes a couple days to happen (I know this because I have the tranny cooler a little bit higher than the engine/transmission on my '39Nash and it takes about two weeks of sitting before it does this leaking thing).
    What about the front pump. There's a paper flat gasket and a rubber ring that goes around it before going into the case, but has this been changed? It's the only other thing and the seal that could now be leaking somehow.
     
  4. core

    core Member

    Joined:
    Nov 1, 2012
    Messages:
    130
    Likes:
    1
    Each time a new stall converter is installed the front pump pushing and gasket had to be changed also do to damage. I need to get the car back I to the shop and have the tranny looked at, but all of the same signs of failure are there.
    I'm not sure if the pump itself has been changed. So if there is to much flued it will leak out by the seal?
    I'll check the level later.
     
  5. dana44

    Ad-Free Member

    Joined:
    Jun 17, 2002
    Messages:
    19,326
    Likes:
    1,238
    No, the seal in the front pump shouldn't leak if the level is too high, it's what a seal is supposed to prevent. The vent is pretty high up on the front pump, located at the top, so the whole case would have to be full of transmission fluid for it to leak, too, so unless you had a two quart cooling coil, that shouldn't be leaking. At this point, if not sure if that front pump itself hasn't been changed, that's the only other piece to change. It may have some damage given all the parts changed around it, converters, center bushing, seals, etc..
     
  6. pt006

    pt006 Active Member

    Joined:
    Dec 24, 2014
    Messages:
    1,284
    Likes:
    491
    Did the vibration go away? Test in park or neutral by varying the engine rpm.

    You said the converter bushing and seal had to be changed due to damage. How was it damaged? If it was scored in one spot, it would be due to case/block misalignment. If it was scored all the way around, it might be due to a bent flexplate. If the tranny is out, the converter could be tested for runout by putting the indicator tip on the converter oil pump bushing surface and turning the crank. A good time to test post # 16.

    The leak might be coming from the oil pump housing or large housing seal? There is a chamfer on the tranny case where the ring seal goes in and it might have cut the ring seal when it was pushed in. 240 grit sandpaper will knock the sharp edge off. A porous pump housing or a slight crack in the housing would cause this.

    Running out of ideas.
     
  7. core

    core Member

    Joined:
    Nov 1, 2012
    Messages:
    130
    Likes:
    1
    The bushing was scored in One spot which matched the offset that was needed. I'm just waiting for a spot to open at the shop for a closer look. All the other time I've replaced the stall convert I've got three month before it started to leak this time it was three drives.
    The vibration after the offset was considerably less, but more constant. Not sure if someone else was driving the car they would even notice. Before the offset pins where installed the vibration would start around 45 mph.
     
  8. pt006

    pt006 Active Member

    Joined:
    Dec 24, 2014
    Messages:
    1,284
    Likes:
    491
    An engine out of balance will vibrate while the car is standing still, and at a certain RPM. Coins jumping around in the ash tray is one way to tell.
     
  9. AC TC

    AC TC Well-Known Member

    Joined:
    Dec 3, 2004
    Messages:
    2,520
    Likes:
    347
    I Think it doesent line up properly.
    - did they check so it isnt "bent", sometimes you have to use shim stock between the bell and Engine to get Everything straigh.
    You have to check and correct "both line ups".
    It could be like this:
    "--" ok correct line up.
    "_/" bent, not good.
    "-_" out of axial line up not good.
    And the last one wich have both problems:
    "-/" not good.
     

Share This Page

Loading...