manfroni

The TH350 in my '78 did something very strange. Put the car in drive last night and nothing happened. After a few seconds it engaged and was fine. Drove about 20 miles no issues. Went back out to drive home and a smaller lag time of engagement. Just about home (on my street) and smelled some smoke. There was quite a bit of trans fluid leaking on the exhaust very near the starter. Parked it in the drive and it leaked fluid the size of a basketball. Checked the dipstick and there was no fluid on it. Never leaked before and I have never had an issue with this transmission. Any ideas?

REELAV8R

Sounds like the front seal on the trans let go. Just behind the torque converter.
You'll have to drop the trans to get at it and replace the seal. Removing the rock guard around the torque converter between the motor and trans may give you a better idea of where it's coming from.

domenic tallarita

Previous post had good suggestion on problem but it is possible that you were very low on trans fluid and it heated up and came out of the vent tube on the top of the trans. I would invest in enough fluid to get a good reading on the dip stick and see what happens. If it is leaking out of the front seal it will come out of the hole on the bottom of the dust guard while at idle in your driveway.
The flywheel will sling oil in severe cases and it will show up between the bell housing and block.
If the oil is dark it also is a indication that the oil was low and got hot. I am almost sure that your trans has the tube on the top.

Dom

jim in oregon

Quick question..WHEN was the last time the THM350 was serviced, fluid & filter changed by a competent technician??

AS others have said above..possibly it was low on fluid.and simply overheated..during your drive..
AS note to yourself..WHENEVER the transmission isn't acting right..STOP and check for leaks(obvious) and CHECK THE ATF fluid..Best checked when at operating temp..hot..not cold of course..Good luck..hope no permanent damage was done..and it's a simple fix..Jim

manfroni

The transmission was serviced about 3,000 miles ago (4 years). It is leaking at the speedo cable. And the cooling line. Will add fluid and let you know how it acts.

manfroni

Jim in Oregon was 100% correct. The trans had no fluid on the stick. Added 3 quarts and it worked perfectly. It does have a leak at the speedo cable that I will get fixed (and check the fluid far more often) Thanks for the help.