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Technical TH350 - need more help

Discussion in 'Traditional Hot Rods' started by Maicobreako, Nov 2, 2018.

  1. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    So I took some HAMB advice and replaced all the 'outer' seals & new tail shaft seal & bushing. No more leaks. I rigged a loop with clear hose so I could see the pump working. I put 4 qts ATF in, started the engine and no fluid. 2 more qts, nothing, then 2 more. No fluid pumping! Any suggestions, besides rebuilding the trans. or is that what I have to do? BTW, I really appreciate all the good advice I've got so far

    I don't have a vacuum line to the mod yet, shouldn't matter, right?
    CIMG4564.JPG
     
    Last edited: Nov 2, 2018
  2. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,980

    s55mercury66
    Member
    from SW Wyoming

    Was this an operating trans when you replaced the seals and gaskets? Did you replace the filter? If so, are you sure it is installed correctly, so it will pick up fluid?
     
  3. bundoc bob
    Joined: Dec 31, 2015
    Posts: 125

    bundoc bob

    Doesn't take much to kill a 350-400 pump. Especially if the
    thrust main wears in the engine. Pump gears are powdered
    metal and the TC only engages the inner rotor part way, which
    is why you will see flat washers between the TC and driveplate.
    Also, chevy driveplates will crack all the way around at the
    crank flange. You can try revving the engine with a timing light
    on the damper, sometimes a worn thrust shows up by the damper
    moving back and forth. You could pull the bottom bell housing
    cover and see if the TC turns with the engine running. With
    the 3 bolts removed from the TC [don't forget to shut the engine
    off first] you should be able to wiggle the TC back and forth into
    the pump. If the inner rotor has died, usually you can't get any
    movement for and aft. Usually a dead pump makes no noise
    with the engine running. Lastly, or maybe firstly, check the
    trans fluid level after the car has sat for 12 hours or so, before
    starting the engine. Level should be way above the full mark.
    Start and run the engine, check the level again. Should be
    lower, if not the pump is dead.
     
    harpo1313 likes this.
  4. gimpyshotrods
    Joined: May 20, 2009
    Posts: 18,114

    gimpyshotrods
    ALLIANCE MEMBER

    How many quarts to you have in this, exactly.

    Depending on the torque converter diameter, a TH350 takes 10 to 11 quarts.

    With an external cooler, and lines, a little more.

    I usually put in 8 quarts, and then check the dipstick with the engine running, bringing it up to the ADD line, cold, and then check it hot, adjusting as necessary.
     

  5. gimpyshotrods
    Joined: May 20, 2009
    Posts: 18,114

    gimpyshotrods
    ALLIANCE MEMBER

    And yeah, your pump might be shot.
     
  6. Bluestone
    Joined: Dec 25, 2016
    Posts: 41

    Bluestone

    Did you put transmission to drive? Once I overfill ot Mopar tf904 and tried to remove fluid by removing the coolerline from radiator. Started the engine: no single drop from coolerline. Put it to drive: instant pink decoration on garage walls. Fan sprayed fluid allover .....
     
    czuch likes this.
  7. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    I don't know it's history :(

    Yes, new filter.
     
  8. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    2 gallons. Yes, it's way up the dipstick.
     
    John Lee Williamson likes this.
  9. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    Tried park, drive and reverse, no change.
     
  10. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    Can't hear anything with the open headers. Will check the stuff that you said. THANKS
     
  11. Patrick Crumley
    Joined: Sep 12, 2018
    Posts: 27

    Patrick Crumley

    This may be a redundant question, but is the TC bolted to the flexplate?

    Sent from my moto z3 using The H.A.M.B. mobile app
     
    Maicobreako likes this.
  12. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,980

    s55mercury66
    Member
    from SW Wyoming

    Well, if all the checks reveal proper installation, buy a manual, pull the transmission, tear it down, inspect everything, replace all the wear items and any other bad parts you may find. Is this going in a race car, or something with serious horsepower? If not, cheap parts will do fine (flaming starts here). A new torque convertor, cooler, and a shift kit would be on my must have list. If you have never been inside an automatic transmission before, here is a great opportunity to learn.
     
    clunker likes this.
  13. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    GOOD NEWS! , (maybe)
    The TC wasn't even bolted to the flex plate. It's about 3/8'' away from the plate. Don't know why. Tried to contact PO but no luck. We had a big storm last night and the garage leaked some, tried to do this without laying in a puddle.
    Wadda you think, bolt it up and see what happens?
    I read somewhere to put washers in if the gap was too much? But also that the plate needs room to flex.

    CIMG4656.JPG CIMG4659.JPG CIMG4663.JPG CIMG4661.JPG
    That's a 3/8 bolt in between to measure.
     
    Johnny Gee likes this.
  14. saltflats
    Joined: Aug 14, 2007
    Posts: 10,731

    saltflats
    Member
    from Missouri

    Looks like the flex plate is on backwards to me.
     
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  15. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    Crap! You're right. checked the web and there's tons of 'flexplate on backwards' stuff.

    So, I've got to pull the trans and swap it around, right? Since I'm doing this, would it be smart to replace pump seals / gaskets right away ? Anything else?
     
    czuch likes this.
  16. saltflats
    Joined: Aug 14, 2007
    Posts: 10,731

    saltflats
    Member
    from Missouri

    You only need to move it back about a 1 1/2 inch's.
    I install two long bolts in the bell housing, then with along wrench reach up and remove the bolts from the flex plate.
    I have done countless replacement jobs.
    On a lift it takes under an hour.
    My thought, if I was pulling the pump to reseal, I would take the complete transmission apart and have a look see.
     
    mad mikey and olscrounger like this.
  17. F-ONE
    Joined: Mar 27, 2008
    Posts: 2,761

    F-ONE
    Member
    from Alabama

    That'll do it...or better yet not do it.o_O
    I'd move that joker back, flip the plate and put it right back,
     
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  18. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    My thought, if I was pulling the pump to reseal, I would take the complete transmission apart and have a look see.[/QUOTE]
    Except I don't know what I'm looking at . The long bolts is a good idea. I can also hang the trans from a roof beam as there is no body on now.
     
  19. ^^^^^ Correct what's visible and go from there.
     
  20. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,980

    s55mercury66
    Member
    from SW Wyoming

    If you have that much access, I would pull the trans, and save a few scraped knuckles, that being the hazard of replacing flex plates without dropping the trans. If you go the long bolt route, take care to leave the convertor engaged. If it drops out, you can get it back together without the drive tangs on the pump engaged. Destroys front pumps in short order :eek: :mad:
     
  21. squirrel
    Joined: Sep 23, 2004
    Posts: 48,678

    squirrel
    Member

    That will be fun..... The lip on the flex plate might be stuck on the crank, and might also be bent.

    Sent from my Trimline
     
  22. 56sedandelivery
    Joined: Nov 21, 2006
    Posts: 6,695

    56sedandelivery
    ALLIANCE MEMBER

    At least you've found the problem! I'm not sure I'd tear into the transmission though, unless the PO did that work too. If a trans shop did the work, I think I'd leave it alone. The bevel on the flexplate's register hole faces the transmission. My younger brother had a 4 door 55 Chevrolet once, and a neighbor gave him a couple of truck mud tires for the rear (you could hear him coming a couple blocks away; those tires were loud). He swapped the tires out in the street in front of the house, and took the wheels/tires to a service station to have them dismounted/mounted. Before he let the car off the jack stands, I went out to have a look, and glad I did. He'd installed the lug nuts backwards, with the cones facing out! When I pointed it out to him, he said he did that intentionally; he thought it "looked better that way". No, he's not much of a mechanic, but he can hunt/fish. I'm with squirrel here; you may have a problem getting the flexplate off the crank flange. There's a small circular recess at the base of the register bung on the crank. Put the flexplate on backwards and the bevel will seat into that recess; tighten the flexplate bolts and distort things, then it makes it difficult to pull the flexplate off. Good luck. I am Butch/56sedandelivery.
     
    olscrounger likes this.
  23. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    Yeah, I'll pull the trans next week and see what's what.

    Thanks all...
     
    gimpyshotrods likes this.
  24. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    Are these lugs meant to be used as lift points? CIMG4664.JPG
     
  25. squirrel
    Joined: Sep 23, 2004
    Posts: 48,678

    squirrel
    Member

    they are used to hold the casting in place on the assembly line as the case is machined, etc.
     
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  26. olscrounger
    Joined: Feb 23, 2008
    Posts: 4,233

    olscrounger
    ALLIANCE MEMBER

    squirrel nailed it again-I cut them off the clear linkage etc.
     
  27. Maicobreako
    Joined: Jun 25, 2018
    Posts: 127

    Maicobreako
    Member

    Thanks. I'll use straps underneath.
     
  28. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,980

    s55mercury66
    Member
    from SW Wyoming

    Don't be afraid to use them as lift points, there should be another one on top of the case forward of the tailshaft housing also.
     
  29. squirrel
    Joined: Sep 23, 2004
    Posts: 48,678

    squirrel
    Member

    yup, they are strong!
     
  30. I hope that is paint and not powder-coating on the case....
     

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