Packard Forum Index » V-8 (1955-56)

Hello, The Ultramatic trans on my 56 Executive push button trans is leaking at the tail shaft seal to the driveshaft, and leaking at the small square box at the D/S of the trans. Shift selector? The plate at the bottom someone gooped it up but it still leaks. What will happen if I remove the two screws and put on a better seal? Is there anything inside that box that might fall out?

For the square box, can you send a photo? Closest thing with 2 screws I can think of is labeled 3.314274 here:packardinfo.com/xoops/html/modules/parts ... PlateNumber=34C&partslist=1955-1956

If that is leaking trans fluid then you have bigger problems. The selector shaft seal must be bad. To replace it requires dropping the pan and disconnecting the various selector shaft items. So a little involved.

Tail shaft seal you will want to disconnect the driveshaft, undo the bolt, pull off the flange, pry out the old seal, and drive in the new. Pretty easy, relatively speaking. Be sure to follow the torque specs in the manual.

I also cannot think of anything like a square box on the drivers side of the transmission. There is a round can like object with two wires going to it positioned slightly above the actuator. That item is the pressure switch but UNLESS someone has changed out the stock round switch with something not stock and square then the only other squarish bit is the cover plate at the bottom of the actuator where you tighten the setscrew which holds the worm sector to the selector shaft.

If Pgh Ultra is correct and the shaft seal is leaking allowing fluid to get into the actuator, you really do not want to seal it tightly as fluid could collect and if trapped, reach a high enough level to possibly affect the contact segments and fingers. It is also possible fluid is not reaching the actuator and is in fact leaking out the small space between the case and actuator. I believe when new there was a small felt ring or washer between the two as sort of a dust seal but chances are that is long gone.

While some have disagreed with adding holes to the actuator saying the extra holes allow splashing water to get inside, S-P service actually suggested adding two small vent or drain holes to the actuator so any condensing water or leaking fluid could escape.

Yes, I am referring to the the selector unit, it has a small plate at the bottom with two screws. That seal has been replaced three times. When I bought the car some years ago I sent it to Robert Escalante at Custom Auto in Santa Ana. They did a thorough (and expensive) sympathetic restoration, repairing all items needing work as well as some cosmetic items. The car now presents as a low mileage (36K) well cared for used car. They did point out to me the leaking selector seal and replaced it. However, the car continued to leak. Last year I sent it to a local transmission shop that was willing to work on older vehicles. They serviced the transmission and replaced the seal (rather expensive). Arriving home, I found it leaking even more. Sent it back and they replaced the seal again (more money). They had the car up on the lift and showed it wasn't leaking. But after driving home, I had a puddle in the driveway. I put it on my lift and found it still leaked. Yesterday I put the car on the lift and found no leak, however I then checked the dip stick and found the transmission 3 quarts low. Refilling started the leak once more. The tail-shaft seal leak is much less, really only a dribble. Since the operation of the transmission is fine, I am wondering if their is something internal that is blowing out the seal? Good luck finding anybody to work on it. I'd be we willing to ship the car to LA or SF if I found someone that can fix it. I know about Russ over in Tehachapi, CA but I don't have the knowledge and I am too old to R&R the transmission myself. I hate the idea of modifying the car with an updated trans, but I am tired of fluid soaked cardboard under the car.
Regards to all who had the patience to read this. Jerry

Not sure where your at

But there is a guy around San Francisco

Who works on the ultra.

For clarification the seal that has been replaced three times is the seal on the small plate at the bottom of the selector unit.
There should not be fluid in the selector unit.
Fluid is often found leaking from the manual valve lever shaft seal where it exits the transmission housing before entering the selector unit. If it is leaking from the shaft seal, it could run along the shaft to the selector unit and down to the bottom plate and drip from there. Check for fluid along this path.
If you remove the small plate on the bottom of the selector, you can check for fluid inside the selector.

Fluid could also leak from the vent and the pressure switch and run along the transmission housing down to the manual valve lever shaft.

If nothing is dripping down from above and the round shaft seal has been replaced that many times and is still leaking allowing fluid to migrate into the actuator then it sounds like there is some kind of damage to the bore where the seal is pressed into or on the shaft itself where the seal lip rides. Any dirt, scratches or gouges on the shaft or bore surfaces will prevent a good seal and fluid can leak past. Either way, the transmission may need to come out to do the job properly and you may need to replace both the shaft and the seal before the leak is fixed. If it is the bore which has the problem then some Permatex around the inner bore or new seal outer edge when it is pressed in would probably do the job in stopping that leak.