Adam Friend

Hey fellas (and ladies), this is my first post on the forum, so hopefully I'm in the right place.

I have a 1968 Mustang Coupe with the 289 and C4 transmission. Over the previous summer, the car would drive fine when it was cold started or left in drive. However, if I stopped briefly after the transmission was hot (gas station etc.) drive will not engage until things have cooled down a bit.

Now that it has been 'resting' all winter, I notice there is a transmission fluid leak coming from the pan, which I assume can be repaired with a gasket change.

I'm capable of handling a moderate amount of engine work, but have never worked on a transmission... tips or ideas?

jonward786

Check your tranny fluid levels. My C4 was over a quart low one time and then one day it wouldnt shift out of park

boogerschnot

Change the fluid, filter, and gasket on the tranny. Its not terribly hard, you just have to watch where the fluid goes when you lower the pan (if you dont have a drain plug) so that it doesnt make a mess. Fill it up with new fluid and see how she runs afterwards.

jlg2002

I would also advise on draining the torque converter (TC) as well. Be sure to use type "F" if you haven't ever had the trans reworked. (Mercon does work but the old seals and bands don't have the correct characteristics to use it for long). Put 4 qts in and start the engine idle for 1 minute then shut down and add 3 more - that should fill the TC - restart and continue to add fluid until you're at the COLD fill line on the stick.

Adam Friend

Thanks, everyone. I picked up a new seal, filter, and fluid yesterday... hopefully I'll get a chance to flush it out this weekend.