It's about time I change the transmission fluid in my 72 f100. I've never done it before so is there something I need to know before I begin? Is it just like changing the oil? Tips? Thanks for all the help

 

if manual, then it's a drain and fill.
if auto, there is a filter and pan gasket that will also be needed

 

It's an auto. If the gasket was old would it create a leak? Ever since I got it it would leak tranny fluid when I parked

 

yes, It would also leak if the bolts were over tightened. Make sure the bolt holes are not bent in. This would also cause it to leak.

 

With an auto trans, consider attaching a strong magnet with epoxy to the inside of the pan. The magnet will catch metal grit that the filter is unable to catch.

...an ounce of prevention is worth a pound of cure.

 

Unfortunately, factory automatic transmission pans don't come with a drain plug in these old trucks. (You can add one though --but it will be AFTER you initially take the pan loose).

Put your drain pan under the transmission and start loosening the pan bolts from the rear to the front. Loosen them only a little bit with the rear bolts being run out a little more than the front and break the seal the pan has to the gasket. The fluid will come pouring out

This will let the back of the pan slope down a little more than the front to make the majority of the fluid run out the back of the pan. --somewhat controlled but, still a good chance it may be messy.

Once most of the fluid has run out, you can take the pan off. Remove the old gasket material from the flange of the transmission and the pan. Swap out the filter.

This would also be a good time to put a new seal in the tail housing. If fluid is leaking out the front, from the bell housing, the transmission would have to be slid back away from the engine and the torque converter removed to change out the front seal.

There is an O-ring inside the transmission around the shift lever on the left side of the case. If it's leaking around the shaft, it would be a good time to replace it, while the pan is off.

 

This helps a lot. Thanks so much. Being 16 with little experience I like to browse this site. Many interesting threads.

 

You might want to check into the cost of having it changed and not having to screw with it. I still change engine oil, but take the trannys in.



John

 

There's also an o-ring on the dipstick tube which can be the source of the leak. Worth a few minutes time to replace that one too.

 

The leak could even be the front TQ converter seal. Or even the tail housing seal where the drive line going in.

Many places for leaks. Best to first clean off the old fluid/oil then drive it some then check for the leak.

Orich