727 trans pan leaking again

[Ukpauly]

Hi
I have recently changed my trans pan
As old one was leaking so new fluid
Filter gasket all sorted but it’s leaking badly again has any one else had this issue It’s driving me mad!!!!

 

[Bee1971]

Yep many many times on numerous 727 s

And not one of them was the pan gasket or pan dripping

 

[Car Nut]

Have you checked the selector shaft seal, mine leaked, looked like the leak was coming from the pan.

Easy to replace while the trans is still in the car.

 

[Ukpauly]

Have you checked the selector shaft seal, mine leaked, looked like the leak was coming from the pan.

Easy to replace while the trans is still in the car.

Thanks fotr the reply I am sure that will need to be replaced at some point however leak is on passenger side front corner closest to back of block
Really dripping out quite badly

 

[Ukpauly]

Yep many many times on numerous 727 s

And not one of them was the pan gasket or pan dripping

What was causing the leaks ?

 

[5.7 hemi]

You sure it’s the pan and not the “o ring” on the fill tube?

 

[moes]

make sure the pan rails are good and flat and I've never had leak using the Mopar 727 transmission pan gasket 2464324ac and it is reusable to.

 

[steve from staten island]

My O ring on filler tube was leaking. Also the tube itself was bent. If thats the problem A &A transmissions sells both a factory correct tube and a aftermarket. The aftermarket uses a shoulder type grommet that will not leak. Moparnation who is one of my go to guys for these cars advised some I think sealant like 3m. Let it set up 24 hours. You have to make sure your pan is flat. Moroso sells a gasket with steel encased inside. However any good gasket should work. Again check out that filler tube. I went nuts trying to stop the pan leaking and in the end it was mostly the filler tube. Good luck!

 

[747mopar]

Best thing is always to thoroughly clean everything then check it frequently to nail down exactly where it's coming from. Like others are saying it may be running down from somewhere else. If it is the pan check the pan for flatness, don't over torque and clean the surface well.

 

[Bee1971]

What was causing the leaks ?

Mentioned already in this post

1) Selector Shaft Seal

2) Dipstick Tube O - Ring

3) The one that always gets overlooked , because it is literally right above the pan in the rear of transmission

Rear Band Pivot Shaft O - Ring

 

[Bee1971]

Thanks fotr the reply I am sure that will need to be replaced at some point however leak is on passenger side front corner closest to back of block
Really dripping out quite badly

Already mentioned

That’s the area of the filler or dipstick tube

O - Ring

 

[Ukpauly]

My O ring on filler tube was leaking. Also the tube itself was bent. If thats the problem A &A transmissions sells both a factory correct tube and a aftermarket. The aftermarket uses a shoulder type grommet that will not leak. Moparnation who is one of my go to guys for these cars advised some I think sealant like 3m. Let it set up 24 hours. You have to make sure your pan is flat. Moroso sells a gasket with steel encased inside. However any good gasket should work. Again check out that filler tube. I went nuts trying to stop the pan leaking and in the end it was mostly the filler tube. Good luck!

Thanks for your help and guidance much appreciated will check out the filler tube first

 

[Ukpauly]

make sure the pan rails are good and flat and I've never had leak using the Mopar 727 transmission pan gasket 2464324ac and it is reusable to.

Many thanks will get one of those gaskets on order

 

[Ukpauly]

Mentioned already in this post

1) Selector Shaft Seal

2) Dipstick Tube O - Ring

3) The one that always gets overlooked , because it is literally right above the pan in the rear of transmission

Rear Band Pivot Shaft O - Ring

Many thanks will get all checked out

 

[AR67GTX]

I solved my leaks (I think - knock on wood) with a new pan and a blue silicon gasket. I think that pass side front corner is where the pan sort of juts out and the corner is sort of cantilevered past the bolts on either side. Need to check that area on the pan flange with a straight edge closely since if it deviates down, away from the transmission housing - there is just about no way to sufficiently clamp and seal that corner. But as others have pointed out, that's in the area of the dipstick tube and seal. I also flat filed my case surface flat when I had it apart for rebuilding - but it shouldn't be necessary with a good pan and gasket.

 

[65hemi]

While you are under there checking things, check the neutral safety switch is tight. I had a leak there.

 

[mopar jack]

Just corrected all the leaks from my 727 that have been persistent for a couple of years. The usual suspects, shift lever seal. pivot shaft o ring and the pan gasket. The pan gasket was the hardest to resolve until I noticed the pans have a defect at the front lip. Notice the half circle in the lip of the pan. Allows the pan to flex

 

[mopar jack]

I resolved the issue with a piece of 3/4 angle iron bolted across the weak point.

 

[69 GTX]

A cast alum pan will cure a lot of leaks.

 

[Pistol Pete]

The best way that I've found to nail down where the leaks originate is with small pieces of paper towel. Hose the trans down well with brake cleaner or (my personal favorite) starting fluid. Get it clean and put little pieces of paper towel near all of the above mentioned points. Wait a bit and the towel will wick up the trans fluid in short order, turning pink and showing you exactly the offending leak(s). There may be several.