The Dreaded Tranny Pan Leak

Transmission and Drivetrain Tech

  1. 512Stroker

    512Stroker We are all here because we are not all there.

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    I have checked the dip stick tube several times, no luck, it is sealed up good. I was hoping that it was the tube o-ring it would have been an easy fix.
     
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    • fishmens67

      fishmens67 Well-Known Member

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      It sounds like you know what you are doing. Good Luck.
      I know what you are going through.
      Don't throw money at it like I did, I spent hundreds until I found the 25 cent O-ring fix.
      Chime in when you find the cause, I'm curious. Thanks
       
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      • CudaFactHackJob

        CudaFactHackJob FABO Gold Member FABO Gold Member

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        Sometimes the pan rails are distorted up to half an inch on some of the pans I take off. They've been beat on, twisted, dropped, rusted, and mangled. They NEVER leak. My pan gaskets cost $3.50 ea. I use absolutely NO SEALER whatsoever. I use ONLY Duraprene gaskets. CORK??? OMG NO! Rubber? no. Some kind of cork neoprene mix? NO. FLAT pan rail? NO. The holes have to be massaged until they're about 1/16" low. That way the bolt will apply pressure between the bolts as they're tightened down. Then the last turn or so crushes the rail around the bolt. I crank them down ALMOST hard enough to strip the holes. A Duraprene gasket will NEVER split. EVERY pan has to be hammered on before it's re-installed. If I remove the pan after a few months, it has to be pried slightly to separate it from the case.
         
      • halifaxhops

        halifaxhops It's going to get stupid around here! FABO Gold Member

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        Here is one that drove me nuts. The trans had a 1/4" bolt hole for mounting the dipstick to. Worth a fast look.
         
      • limegreen70

        limegreen70 Pokorny Enterprise's

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        Seems like everyone has a different opinion. I am going through the same thing right now. Ugh it's a nightmare
         
      • toolmanmike

        toolmanmike FABO MODERATOR Staff Member FABO Gold Member

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        Just curious, does it leak only when it sits?
         
      • 512Stroker

        512Stroker We are all here because we are not all there.

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        Leaks just sitting and going down the road.
        The exhaust system down stream of the trans is stained from trans fluid.
         
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        • toolmanmike

          toolmanmike FABO MODERATOR Staff Member FABO Gold Member

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          Deep pan. You running a filter extension?
           
        • 512Stroker

          512Stroker We are all here because we are not all there.

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          Yes, deep plus 2 quart stamped pan with filter extension
           
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          • toolmanmike

            toolmanmike FABO MODERATOR Staff Member FABO Gold Member

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            The extension puts the filter down in the fluid. I would try it a quart low and see what it does. A quart low is still 1 quart over stock capacity with the deep pan. You can always add that quart back at any time. It isn't fixing the root cause of the leak but it might help upi diagnose the leak. Just spit balling here. The fluid level with a stock pan and filter is just at or below the gasket surface.
             
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            • supertruck

              supertruck Retired Old Fart stock car racer FABO Gold Member

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              Had the same issue with the 200-4R on my Sport. Changed to the LubeLocker gasket and no problems since.
               
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              • George Jets

                George Jets 1967 Dart 2 Door FABO Gold Member

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                These Transgo shift kits solve lots of problems, like torque converter Drain Back, allows the pump to pump in Park instead of just Neutral, helping to eliminate the mopar morning sickness on start ups.

                Read the description, many improvements for the 727s and 904s. Changes the shift plunger and internally reroutes the inner flow circuits to Pump in Park and help eliminate Torque Converter Drain Back . . over filling the trans pan and causing other leaks.

                I was happy with them when I have used them.

                Transgo.jpeg

                Transgo TFSC Shift Kit A727 A904 Torqueflite Transmission 727 904 Chrylser Dodge | eBay

                eBay item number:
                202662324309
                 
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                • George Jets

                  George Jets 1967 Dart 2 Door FABO Gold Member

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                  Here is the write up on the Transgo shift kit cures: ^^^^^


                  NEW Transgo SK TFSC shift kit for all Torqueflite three speed transmissions from 1960-UP


                  This kit corrects the common problems with these transmissions; Premature converter failure and lockup shudder, burps oil out of the vent, front bushing and seal burnup, engages slow after sitting, leaks oil when parked, loss of power when hot, burnup on hot trips, reduces hub breakage, engine bog on start off from stop, reduces harsh reverse, soft, mushy 1-2 shift, extended 2-3 shift. Along with the increased performance from your vehicle, you'll also see an increase in the life of your transmission due to the reduced slippage. This is the most complete shift kit available and definitely the most reputable.

                  .
                   
                • RustyRatRod

                  RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                  Golly jeepers Beav, I was just trying to stress how important all this was to not bypass. Bozo knows when he's not appreciated. He'll STUFU next time.
                   
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                  • George Jets

                    George Jets 1967 Dart 2 Door FABO Gold Member

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                    It's all good, everyone has their experiences to share. Adds to the total knowledge base. End user can decide what works for them.
                     
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                    • 512Stroker

                      512Stroker We are all here because we are not all there.

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                      No disrespect intended toward you, your message came on a little strong.
                      The straightness of the pan was the first thing I went after.
                      After doing this for over 4 decades I'm getting a little cynical.
                      You are welcome to post on my threads anytime and please do.
                       
                    • RustyRatRod

                      RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                      I meant for it to come across strong. It's that important to get everything perfect. It wasn't meant on a personal level at all. Now when I start out something like "Hay dumbass........" then you can bet it's personal. First off, I would never do that to you, as we've always gotten along. Secondly, that wouldn't be conducive to getting someone to understand the gravity of doing something a certain way.
                       
                    • 512Stroker

                      512Stroker We are all here because we are not all there.

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                      67 factory service manual staes 150 in/lb's for pan bolt torque.

                      Question
                      Does anyone know what the 1/8 NPT plug is for that is right next to the dipstick tube in the trans case? Pressure port?
                       
                    • 512Stroker

                      512Stroker We are all here because we are not all there.

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                      Well I did it
                      Cleaned pan very well with K&N filter cleaner and hot water, than a final wipe down of the pan and trans pan rail with brake clean.
                      Checked pan again for staightness/flat all OK
                      Checked bolt holes for distortion, none found
                      I used the gasket that came with the WIX filter kit, some kind of synthetic, pressed it flat over night with a piece of plywood and alot of weight on top.
                      Sprayed the pan side of the gasket with Permatex copper spray and applied the gasket to the tranny pan.
                      Installed the pan and torqued the pan bolts to 150 in/lb's let it set up for 2 days.
                      Filled trans with Valvoline Dex/Merc ATF drove it for 20 miles parked it over night put it up on the rack, no leakage found at the pan.
                      Job over, I hope.
                      Edit-Thanks to all who replied
                       
                      Last edited: Mar 23, 2021
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                      • CudaFactHackJob

                        CudaFactHackJob FABO Gold Member FABO Gold Member

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                        No sealer, Duraprene gasket at $3.50, and not a flat pan rail. Pooch up the bolt holes so they preload the area between the holes. Been doing it for years; works every time.
                         
                      • RustyRatRod

                        RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                        Don't you mean pooch the holes DOWN in relation to the transmission? That would preload the spaces between the holes that need to seal...
                         
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                        • Don Selleck

                          Don Selleck Active Member

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                          after many attempts i finally got mine to stop leaking, took it off put it on the shelf and put the stock one back on. hasn't leaked a drop since.
                           
                        • CudaFactHackJob

                          CudaFactHackJob FABO Gold Member FABO Gold Member

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                          ..I only work on transmissions that are up-side-down...
                           
                        • Dartswinger70

                          Dartswinger70 Well-Known Member

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                          Not 100 % sure of the pan bolt torque but it is important. I worked in a trans shop and the boss was a stickler about torqueing pan bolts evenly. I seem to remember some of them were in "Inch pounds" also.
                           
                        • 512Stroker

                          512Stroker We are all here because we are not all there.

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                          With great sadness I am compelled to report that the dam thing is leaking again.
                          I have one more trick up my sleeve to make it stop.
                          Stay tuned for further developments.
                           
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