727 gearbox

[Unkle Krusty]

Soon I will install 10228 shift kit. Meantime my question. Does the rear part of the transmission remove easily. I thought it would be a good plan to replace the gasket. This is the rear skinny part. I also have a new rear rubber mount. As always, thank you.

 

[Dave6T4]

Drain the transmission and pull the driveshaft. There is a small cover plate on the bottom of the tailshaft housing, attached with 2 Allen screws that needs to come off. This gives you access to a large snap ring that clips over the rear shaft bearing. Undo the speedometer cable from the adaptor, and also pull the adaptor, with Speedo gear. Note the indexing of the adaptor in relation to mark on the housing. Unbolt the tailshaft housing bolts, spread the bearing snap ring, and pull the housing off. You might want to change out the rear seal at this time, as well. The one with the rubber bellows is the one to use. Since you will have the oil pan off, this would be the time to upgrade to the A-518 pan gasket with steel core and o-ringed bolt holes. This gasket requires slightly longer pan bolts, which Mopar sells as a package. Have fun!

 

[davek]

yes you can

 

[RemCharger]

Drain the transmission and pull the driveshaft. There is a small cover plate on the bottom of the tailshaft housing, attached with 2 Allen screws that needs to come off.

Likely a truck trans, so the snap ring cover plate would be on the passenger side

 

[dvw]

If I was doing the gasket it's best to reseal the rear band anchor pin.
Doug

 

[Unkle Krusty]

Sweet. Thank you again, all replies. The Haynes manual is not much help.
The rear mount on mine is further aft, otherwise it looks the same to me.
Mine was not making any noise, so I will assume the rear bearing is okay. It is too cold to work outside, or I am getting soft. Low thirties is my cutoff. We are having a cold week.

 

[493 Mike]

I cannot recall any transmission extension gasket leaking in over 50 years of rebuilding auto transmissions. But, as DVW suggested, the O-ring on the rear band pivot gets hard and leaks. As Doug has recommended, clean the recess at the end of the pin thoroughly, dry, and fill with silicone sealant.
Mike

 

[RemCharger]

I cannot recall any transmission extension gasket in over 50 years of rebuilding auto transmissions.
Mike

Huh?

 

[493 Mike]

Huh?View attachment 1792061

Opps. left out 1 word=leaking.
Mike

 

[T Brashears]

The pin is the leak back there,Chrysler added a 2 nd o-ring to its later units. If you’re taking the housing off,change it. If not,clean it good and dry it,use you’re favorite sealer.

 

[Unkle Krusty]

I figured as I have it all out. Might as well replace as many gaskets as possible. Do not intend to touch it again.
The main issue with the 727 was the inability to engage first gear, and have it stay there.
We are working hard up and down the many steep hills.
Duffy Lake Road in BC, HWY 20 in the US, and many others.
We weigh 6600 pounds.

 

[T Brashears]

Rebuild it,don’t do all that work twice.

 

[Dave6T4]

I figured as I have it all out. Might as well replace as many gaskets as possible. Do not intend to touch it again.
The main issue with the 727 was the inability to engage first gear, and have it stay there.
We are working hard up and down the many steep hills.
Duffy Lake Road in BC, HWY 20 in the US, and many others.
We weigh 6600 pounds.

Might be a linkage adjustment.