I have a serious oil leak from my auto - I have been told the oil is possibly draining from the convertor over a period of time, possibly coming from the oil filler tube which may not have a good seal.

After I drive my car the leak happens slowly, possibly over a few days if the car has not been driven - resulting in a large pool of oil.

If I drive the car daily I don't seem to have an oil leak (maybe a few drops). Any advice welcome.

Also, can someone tell me in 'easy words' how an auto transmission works.

Thanks,

Pete from Downunder.

If it leaks while not running I don't think the leak is at the filler tube, have you checked where the puddle of oil is in relation to the transmission (front, end), have you checked that it is transmission fluid and not motor oil ? if the engine rear seal has a leak it can be difficult to see if it comes from the engine or tranny.

The front and rear seals of the transmission can leak, it can also be the gasket in the oil pan, try to wipe of as much oil as possible, leave it for a few hours or a day and see if you can see where the oil comes from.

A good description can be found here http://www.familycar.com/transmission.htm but it might be a bit to much detail maybe.

On the above website there is a simple and easy description of how the torque converter works, the gear shifting is done with planetary gears that allow smooth transition from one gear to another using brake bands and clutches, but this is also described in a nice easy to understand way I think so take a look at it.

Crickhollow:

[quote]Also, can someone tell me in 'easy words' how an auto transmission works.[/quote]

Pete, you won’t like it, but here goes: It’s magic!

However perhaps I can help with the leak.

There is a good chance that the torque converter is slowly draining down through the pump, which rises the fluid level in the pan to the point that it is higher than the bottom of the dipstick tube.

At the end of the transmission dip stick tube is an “Oâ€￾ ring. Clean the spot where the tube enters the transmission real well, remove the tube, and replace the “Oâ€￾ ring. That should stop the leak.

Repairing the pump is another story. The transmission will have to come out for that.

My transmission is doing this same thing, draining down over the course of a few days. My "O" ring is good, and no leaks, but after a week of not running, I have to idle in neutral a few seconds to re fill the converter for the car to move. If I run the car everyday it works fine.

Bill

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

still another is the cable shifted linkag connection point-- notorious for leaking, you need to clean off the tranny-- drive it & then inspect exactly where the leak is coming from.
Or just keep driving it & you won't have the leak(ha_)-- let us know Lawrence

On 60-65 cable linkage 904 automatics, this type of leak is usually from the Throttle pressure shaft seal. (kickdown lever seal)
This is a small, all rubber seal, just under the kickdown lever and it is known to "dry-out" and leak.
(see "throttle shaft" in the photo below)

Mopar knew about this problem and changed the seal's design, to a more conventional stamped steel housed lip seal, starting in 1966

Other leak possiblities are the filler tube o-ring, gear selector o-ring and the shift / park cables themselves. If the outer housing gets burned, cut or damaged, fluid will leak directly out of the cable's outer "skin".

Wipe-off the bottom of the trans and inspect carefully to pin-point the source of the leak.
DD