1964 727 Transmission Pan Torque Specs

furyfever

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1964 318 and 727 Transmission in my 58 Plymouth Belvedere. I have had constant transmission fluid leaking issues. Changed out pan gasket and filter twice in 6 years of ownership. Sick of it…so this time I bought a thicker ribbed rubber pan seal for a 1990’s Dodge Ram…Recommended by a mechanic friend of mine but I do not know the torque specs for all the bolts for this type seal. It’s much thicker than what Ive used in past. I guess there’s metal sandwiched inside the rubber too. It’s reusable…Both mechanic friend and guy at NAPA who sold it to me…said no sealant required. Anybody know what I should torque these bolts to?
 

detmatt

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These just need to be a little past snug, the spec is about 12 ft lbs in the service manual. I’d go to 7 ft lbs and if the gaskets not trying to squeeze out at that point maybe go to 10.
 

cantflip

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So pretty much the same as the cork gasket... no sealant and don't torque it like your King Kong :lol:
 

Mike66Chryslers

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I know the gasket you're referring to and they are pretty cool.

Before installing, make sure the flange area of your pan isn't dimpled in around the bolt holes. That would stop the pan from seating properly and lead to a leak, even with the fancy new gasket.

If necessary, support the pan rail, put the ball end of a ball-peen hammer over each of the holes and give it a tap with another hammer to dimple them in the opposite direction a bit.

Are you 100% sure it's leaking from the pan, and not from the shift shaft seal? That can look like a leaking pan because the fluid dribbles down from the shift shaft to the pan gasket area and wets that, then drips off the bottom of the pan.
 

celticwarlock

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I use those gaskets exclusively on every Mopar I own (classic & otherwise). I've never had a single leak with them.

It helps if you are, but you don't *have* to be precise with the torque. Those gaskets are pretty forgiving.
 

furyfever

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Thanks guys...good to know. I'll torque them lightly then but all equal and still start at center bolts ,work opposite sides then corners last. And I hope its not the shift shaft seal! Not 100% sure its the pan but I'm thinking it is because if I remember right...it started leaking a lot after I changed the trans. oil 5 years ago or so. Changed out again a year or two ago and it leaked badly again. We'll see. If I don't bring this thread back to life soon....it was just the pan gasket. Thanks all again.
 

detmatt

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Thanks guys...good to know. I'll torque them lightly then but all equal and still start at center bolts ,work opposite sides then corners last. And I hope its not the shift shaft seal! Not 100% sure its the pan but I'm thinking it is because if I remember right...it started leaking a lot after I changed the trans. oil 5 years ago or so. Changed out again a year or two ago and it leaked badly again. We'll see. If I don't bring this thread back to life soon....it was just the pan gasket. Thanks all again.
My question to you is why do you change your trans fluid so often?
 

furyfever

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Yes, sounds like I change trans. fluid often but, when I bought this car 6+ years ago…the car wouldn’t shift into reverse. I physically couldn’t push R button in to engage trans. into reverse after engine/trans. were at running temp. I changed trans. fluid + filter used regular gasket and thankfully, that fixed the reverse problem but this is when it started leaking, a problem I’m still chasing. A few years later, I changed fluid, filter and gasket again. This time, I even straightened pan using a pick, file and straight edge. It had some slight deformation from tight bolts. I used another regular rubber gasket + consulted a mechanic friend. He told me to put gasket sealant on pan side only and torque (used spec. from chiltons manual) from center bolts outward to edges. That didn’t work either….still leaked. That brings me to today/this thread. I checked today…found several tightly spaced drops on floor this time with thicker, ribbed, rubber gasket, no sealant, bolts torqued to 4 ft. lbs after several days with fluid in it. Fluid seepage seems to be between gasket and pan especially at front of pan…drops of fluid on bolt heads too. I re-torqued bolts to 5 ft. lbs. just a few hours ago. This is earily reminiscent of the past two changes…Can’t believe it.
 
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Gerald Morris

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Yes, sounds like I change trans. fluid often but, when I bought this car 6+ years ago…the car wouldn’t shift into reverse. I physically couldn’t push R button in to engage trans. into reverse after engine/trans. we’re at running temp. I changed trans. fluid + filter and thankfully, that fixed the reverse problem but I created the leak which I’m still chasing. I changed fluid, filter and gasket again a few years later and even that second try did not fix leak. At this second time, I straightened pan using a pick, file and straight edge as it had some deformation over the years, from bolts. I used another regular rubber gasket + consulted a mechanic friend. He told me to put gasket sealant on pan side only and torque (used spec. from chiltons manual) from center bolts outward to edges. That didn’t work either….still leaked. That brings me to today/this thread. I checked today…found several tightly spaced drops on floor this time with thicker, ribbed, rubber gasket, no sealant, bolts torqued to 4 ft. lbs after several days with fluid in it. Fluid seepage seems to be between gasket and pan especially at front of pan…drops of fluid on bolt heads too. I re-torqued bolts to 5 ft. lbs. just a few hours ago. This is earily reminiscent of the past two changes…Can’t believe it.

BELIEVE! Look, unless you have a GOOD QUALITY INCH-LB scale torque wrench, you're apt to all manner of variations in those super low torques you attempt to get right with ft-lb scale wrenches or ratchets. I too have gone through many contortions with tranny pan gaskets, and finally got The Word from the octogenarian transmission mechanic who rebuilt mine some years back now: GET A GOOD STRAIGHT PAN TO START WITH! You'll spend several C notes, but you'll be much more likely top succeed in sealing that transmission.

Inch-lb scale ratchet + good pan, improve odds of keeping that fluid IN.
 

Jakter

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Make sure your bolt holes are flat on the flange, torque to FSM spec. Don't matter what gasket is used. You don't need anything but the factory pan.

I'd look real close at the shift shaft seal, hard to get a good look at but not too hard or expensive to replace.
 

cantflip

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Make sure your bolt holes are flat on the flange, torque to FSM spec. Don't matter what gasket is used. You don't need anything but the factory pan.

I'd look real close at the shift shaft seal, hard to get a good look at but not too hard or expensive to replace.
That may be the most useful post I've ever seen you give :thumbsup:

Good advice, properly installed without getting overly scientific about torque specs (pro's seldom take the time to use a torque wrench on something like this) and a nudge toward the likely problem!

:welcome:, this personality is good for the community. Up to now I figured you were just a troll who didn't care about cars and just wanted to wind up good people. Try sticking with this for a while.
 

Knebel

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I too have some leaki g at the pan, I also discovered almost all my bolts were just hand tight. At 4ft-lbs that just like fingertight and then flick the wrench lol.
 
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