57 312 Auto Trans - Transmission fluid leak

[OhioTbird]

I've had my 57 for about 6 months now and maybe took 6 or 7 drives (Midwest winters meant I was down for a few months.)

This morning I went out and found a transmission fluid leak under the car. I last drove it two weeks ago with no issues. The puddle was about 3 feet wide and front to back, maybe 2 feet. So pretty substantial. It was directly under the seats. Today was the warmest day we've had with temps over 90. That have any bearing?

I checked the dipstick but it showed full (didn't initially know you need to check it while running.) I started up the car and let it idle in a different spot while I wiped up the red fluid. Once the floor was clean, I took the car for an easy, 15 minutes drive careful to watch for any white smoke.

When I got it back in the garage, I checked it again (while idling) and it showed right at the full line where it should be.

I did a bit of checking and read the article about a leak from the yoke plug. Any other thoughts or past experiences any of you might have had similar to this?
I'll head to my local mechanic this week and hope to address this. I have an upcoming road trip but still a few weeks away.

Thanks.

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[doug7740]

The Ford-O-Matic transmission has the potential to leak from several areas. The three most prominent areas are:

• The front pump seal which usually exits from the bell housing.
• The shift selector shaft side seal.
• The transmission pan gasket.

You need to take a look at the underside of your car so you can be more specific as to where the transmission fluid is leaking from.

If the leak is originating from the drive shaft area of the transmission then Gil Baumgartner’s article would apply, or you could have a defective output shaft seal. Depending on your skill level, this is a repair that you could do yourself, because it doesn’t require removing the transmission from the vehicle.

If the leak is originating from the transmission pan area, replacing the transmission pan gasket is another repair that you could do yourself, because it doesn’t require removing the transmission from the vehicle. A shift selector shaft side seal can appear to be a pan gasket leaking, because it usually travels to the rear portion of the pan before it drips. A good way to check the shift selector shaft side seal for a leak is to wipe the area clean and place a rolled up paper towel below the shift selector shaft side seal area and let it sit over night. If the shift selector shaft side seal leaks the paper towel will usually catch the fluid before it can drip.

If the leak is originating from the shift selector shaft side seal on the left side of the transmission or from the front pump seal, than that’s a different story. To perform these repairs the transmission will have to be removed from the vehicle and since you just purchased the vehicle you might as well have the transmission inspected and overhauled.

doug7740
1955 Thunderbird Blue

 

[OhioTbird]

Just got the car back from the mechanic. He found the seal bad by the trans inspection plate.

Took the car for a nice ride to celebrate.