TH350 without oil

Discussion in 'The "Juice Box"' started by Kaule, Jan 22, 2017.

  1. Kaule

    Kaule Gold Level Contributor

    Would it harm the TH350 if the engine is running with no oil in the Transmission ?
     
  2. Matt Knutson

    Matt Knutson Well-Known Member

  3. CJay

    CJay Supercar owner Staff Member

    Do you mean so low on oil that there is nothing showing on the dipstick? Ive had situations where no oil showed on the dipstick and I wound up putting 3 quarts of fluid in the trans. The transmission operated just fine afterwards,

    Or zero fluid? That might cause some real damage rather quickly.
     
  4. knucklebusted

    knucklebusted Well-Known Member

    Was it freshly rebuilt with a brand new converter? If so, that's about the only way to have a "no oil" situation. The converter alone holds about a gallon and the internals probably hold a solid quart. Even if it doesn't show on the stick, the pan could hold 2 quarts.

    But to answer the exact question you asked, yes, it will harm it. Those things spinning without fluid will heat up and damage will be done. It might still work but you will shorten the life.
     
  5. Kaule

    Kaule Gold Level Contributor

    Yes the converter is new and before i take the Transmission out, i have drained the oil.

    The engine has a new cam, i think i must run the 20 minutes / 2000 rpm break in ?

    Is it enough if i fill it once to maximum mark for this break in ?
     
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Unbolt the converter from the flex plate and push it back.
     
  7. CJay

    CJay Supercar owner Staff Member

    Not sure Im understanding you right. Did you fill the converter with fluid before you installed it? How many quarts of fluid did you add in total to the trans? Is the transmission bone dry?

    If your going to break in an engine, have at least one other car guy helping you. The more eyes and ears the better. There is going to be a lot to monitor- oil pressure, temperature, rpm, etc. Once it starts up, have your buddy check the trans fluid and top it off if necessary. Have everything- timing light, vacuum gauge, trans fluid, funnel, rags, all at arms reach so your not looking for stuff.
     
  8. CJay

    CJay Supercar owner Staff Member

    Yeah, that's another solution. Takes the transmission out of the mix for the break in. Once its broken in, you can deal with the trans afterwards
     
  9. Kaule

    Kaule Gold Level Contributor

    Converter installed dry, car was in paintshop after that and i would prevent leaking,
    so no oil in transmission now.

    Installed the trans-cooler lines today.

    I will see how difficult unbolting the converter is. But now it's late here, will check it tomorrow :)
     
  10. Matt Knutson

    Matt Knutson Well-Known Member

    The converter Should Not be installed dry. You need to pour at least a quart and no more than two quarts into the converter so that the pump does not cravitate.
     
  11. Gary Farmer

    Gary Farmer "The Paradigm Shifter"

    Willkommen im Forum. Ich hoffe Sie finden was Sie hier suchen.

    Mein Deutsch ist nicht gut, aber alles ist verstanden, ja?

    Dein Englisch ist klar.

    The ST/TH 300/350/375/400 transmissions are nearly 'bulletproof' as long as there is some fluid in them, unlike the finicky overdrive transmissions which can burn up if they have a hiccup or burp of air to digest, saying nothing about a maladjusted TV cable...(hey, it can happen).

    Ask yourself this question: would it be better to shorten the life of and/or destroy the transmission with unlubricated parts (would you start a bone dry engine without oil?), or would it be better to pull the transmission back out now before the damage is done in order to put two quarts of fluid in the converter, two quarts into the dipstick fill tube, and wait until after the engine is broke in before hooking the transmission back up and warming it, going through the gears to put fluid into the journals/clutch packs, checking the fluid level after this, then adding fluid one quart at a time, topping it off once it reaches ambient operating temperature and becomes visible on the tip of the dipstick.

    I'm not a pro, but this is how I've always done it and everything turned out ausgezeichnet. :)

    While this is not bad advice, it does require the most work and is the safest way. Perhaps others here would have a simpler solution that would still be safe, such as disconnecting the converter and pushing it back into the trans so it doesn't contact the flexplate on the engine, then pouring a few quarts through the dipstick after hooking up the converter and adjusting it properly. After this, the aforementioned break-in procedure would be applicable. I would fear this way would keep air in the converter too long before the pump could prime and some damage could occur, but maybe I'm wrong?

    I would think that whoever rebuilt the transmission coated everything with transfluid before assembly so it shouldn't be absolutely dry...

    I'm not a transmission pro, so get as much advice as you can before proceeding with anything.
     
  12. knucklebusted

    knucklebusted Well-Known Member

    Was the converter brand new and never used or did you just drain most of the fluid you could?

    My first choice would be to disconnect the torque converter from the flywheel and break in the motor. Once that is done, consider these transmission options if you don't need to pull the trans for any other reason. Someone at a transmission shop could also weigh in.

    1) Fill the pan to the full mark then manually spin the converter over several revolutions. This should be minimally enough to get some fluid to prime the pump. Check the fluid level to see if it pulled any in. Bolt the torque converter to the freshly broken in motor and start it briefly. Check fluid and add if needed. Restart again and let run, check fluid, add as need to get to at least register on stick. Cycle through the gears then check again.

    2) You might (BIG MIGHT) be able to pump a quart or two of fluid into the outlet cooler line to fill the torque converter. I believe the fluid path will go to the convert and front pump. You could also pump a quart into the return line just to be sure. It may be slow going but gravity should work on both lines. You won't fill the converter completely but certainly enough to make sure oil flows. Check the dip stick before and after to see if any of it made it to the pan.

    3) Some torque converters came with a drain plug. You could rotate it up as high as possible and fill it as much as it will hold. Again, it won't fill but it won't be dry and will pump fluid pretty quickly.

    Good luck and keep us posted.
     
  13. rmstg2

    rmstg2 Gold Level Contributor

    If you disconnect the converter the engine will react differently than with the converter hooked up, it will rev quicker and die easier if the tuning isn't close.


    Bob H.
     
  14. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Yes, but I believe he wants to break the cam in, so for that purpose, pushing the converter back is the simplest solution.
     
  15. sean Buick 76

    sean Buick 76 Buick Nut

    Am I missing something or why not just wait till the trans leak is fixed, the is ready to be filled and then break in the cam then? Regarding installing the torque converter dry.. I would not bother pulling the trans to add the fluid now but yes it is a good idea and best practice to add some fluid to the converter before hand. But is it worth removing the trans to do this?
     
  16. Matt Knutson

    Matt Knutson Well-Known Member

    Yes

    No one mentioned a leak
     
  17. BRUCE ROE

    BRUCE ROE Well-Known Member

    The torque converter acts as a flywheel to smooth the engine. Hard to say how
    it will run without it. Bruce Roe
     
  18. sean Buick 76

    sean Buick 76 Buick Nut

    Yes he mentioned possible leaks:

     
  19. Matt Knutson

    Matt Knutson Well-Known Member

    I did read that and to tell the truth - I am a bit confused as to what exactly is going on here. The best I can tell he already had the trans out, but, who knows. I will step away and wish him all the best.
     
  20. rmstg2

    rmstg2 Gold Level Contributor


    See post #13:grin:


    Bob H.
     

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