Re: aluminum case A-727 leaks
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Re: aluminum case A-727 leaks

We recently took care of all the leaks on the pushbutton A727 in our 64 Dodge 880. (Thank god for a 2-post lift.)
We originally thought the majority of leakage was coming from the pan gasket, but this was not the case.
The seal on the kick-down lever turned out to be the major culprit. I’d say the filler tube o-ring was next worst.

Here’s the list of potential leak points — basically every location where there is a penetration, plus the pan.
Granted, later Torqueflites don’t have the shift and park cables, but they do have a shift lever penetration similar to the kick-down lever in design.

* Trans fluid filler tube O-ring
* Kick-down lever seal
* Shift cable O-rings
* Park cable O-rings
* Speedometer cable O-rings
* Pan gasket

Here are some useful tips:

Be sure to straighten the pan as best you can before reinstalling it. Not all the bolt holes have stiffening ribs stamped in between them, so pay particular attention to these locations. When you think you’ve got it nice and flat, go around again with a straight edge and straighten it some more. It is worth the extra effort. Don’t overtorque the bolts! This is what warps the pan and causes leaks in between bolts. Spec is only 10 or 12 ft-lbs. Check your service manual.

To check your work, put some indicator dye in the trans fluid and drive the car a few miles. Then use a UV flashlight to inspect for leaks. Any fluid that’s leaked out will glow a bright fluorescent green. Here are links to the dye and LED UV flashlight we bought on Amazon (all free shipping w/ Prime):

Interdynamics 374CS Certified A/C Pro Oil and Fuel Systems UV Dye


OxyLED OxyWild 51 LEDs Pet UV Urine Stain Detector Blacklight Flashlight


Lastly, don’t forget to change your filter and fluid. I got tired of not finding ATF+4 in the parts stores these days, so I bought a gallon, also on Amazon:

Mopar Brand Automatic Transmission Fluid, 1 Gallon


Dan Davids

P.S. You can play CSI with the UV flashlight to check the carpet and floors in your house. This will no doubt be entertaining, especially if you have pets.

Ricky asked "But seriously, how many seals are the in the aluminum case A-727?
My ’62 shifts fine, but drips – seriously thinking about taking it to Pat Blais just to replace all the seals if nothing

So maybe we can put together a list of common failure points on the PB 727 for leaks. Here are a couple to start:

* O-ring on the trans filler tube
* trans pan gasket


Gary H.

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