Superturbine 300 pan leaking...

Discussion in 'The "Juice Box"' started by 1966buickgs, Jul 29, 2016.

  1. 1966buickgs

    1966buickgs 1966buickgs

    How do I get this pan to stop leaking.It is a rubber felpro gasket. I have used Indian head gasket sealer didn't work.I have used RTV. Did not work either. Felpro says to install dry on both sides. Am I over tightening? Thanks
     
  2. sailbrd

    sailbrd Well-Known Member

    switch to a cork gasket
     
  3. 1966buickgs

    1966buickgs 1966buickgs

    Okay what sealer should I use on the cork gasket,or install that dry too?
     
  4. LARRY70GS

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

    The pans are frequently over tightened which warps the flanges. That alone causes leaks. Take the pan off and use a small hammer to flatten them. You shouldn't need any sealer with any gasket if everything is flat. Torque is no more than 15 ft. lbs.

    BTW, other things leak on transmissions besides the pan gasket. Are you absolutely sure that the leak is coming from the pan?
     
  5. 1966buickgs

    1966buickgs 1966buickgs

    Yes there is other small leaks coming from the side with the shifter linkage an the dip stick,really small leaks though. The main leaks are definitely all pan an are a problem. I got another rubber gasket from Napa that I will put on dry tommorow an I will check the pan again to make sure it's not bent. Now 15lbs of torque is what I will try.Is there a certain order of tightening each bolt? really don't wanna do this again but it's gotta be right!
     
  6. LARRY70GS

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


    No order, just tighten each bolt a little at a time until you get to 15 ft. lbs. The manual says 10-16 ft. lbs. The pan flange must be flat.
     
  7. 1966buickgs

    1966buickgs 1966buickgs

    Ok thanks,by the way what transmission fluid do y'all recommend for this st300?
     
  8. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    Dextron 2. Also make sure that small lip on the very edg all the way around needs to look the same, snug and Half a quarter turn or a little bit more is good torque
     
  9. GS Spoken Here

    GS Spoken Here Well-Known Member

    From what I have been told, rubber gasket needs to be installed dry, and put it on the pan and put the bolts on the pan before install. Make sure the trans pan rail is very dry, and do not over tork the bolts. Another place the trans can leak is the plastic connector for the kick-down. It get old and cracks and leaks, and the O ring will not hold. The one I took of my 68 came off in pieces, had to replace it and O ring. Thanks Bill.
     
  10. LARRY70GS

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

  11. 1966buickgs

    1966buickgs 1966buickgs

    Ok installed the gasket dry on both sides this time an torque wrenched to 15lbs. of pressure all the way around. It still leaks though because the pan is warped on one side, it is not completely flat an true. I tried to flatten it back out but no success with that flange that folds up on it makes it difficult to get it just right again where it once was flat an level. If anyone has a good one let me know or has any ideas on this,thank you.
     
  12. 1966buickgs

    1966buickgs 1966buickgs

    I don't ever give up! It was the rubber felpro gasket an the pan being slightly warped. So after hitting it with a rubber hamer for a bit an 3/8 T handle allen wrench we got it flat again. Then I installed a cork gasket this time dry on both sides an made sure that everything was smooth,clean,and dry. NO LEAKS FINALLY! Oh an I did torque to spec of 15 lbs again. Thanks everyone!
     

Share This Page