Transmission pan leak on 92 F250 Diesel

I’ve been losing transmission fluid on my truck for about a year now. Since it’s an old clunker that I just use to tow my horse around with–and I’ve sent my mechanic’s kid through college with it’s previous repairs–I’ve just sort of lived with it.



Yesterday, I changed the oil on the beast and since I was spending quality time under the truck anyway, I ran the engine and looked for the leak. I turned out to be coming from the oil pan, seeping out near one of the screw heads that holds the transmission pan onto the body of the transmission.



Can I try tightening this screw myself in the interest of saving money or do I run the risk of totally screwing up the gasket between the pan and the transmission. If I try it should I use a torque wrench (something I don’t have but probably should buy some day.

Tightening the pan bolts (all of them) is a good idea. It may help, or it may not, but you have nothing to lose by trying. I’ve stopped, or slowed, oil leaks this way more than once. Just don’t OVER tighten the bolts.

A torque wrench is a good investment if you’re going to do any vehicle maintenance, but Im not sure you need one for this project. It certainly wouldn’t hurt, but you can tighten the bolts a little bit without a torque wrench. Again, don’t over do it. You don’t want to break off a bolt head.

it probably needs a service. being a farm truck it probably hasnt been done. its not that hard to do, the torque convertor even has a drain plug so you can change just about all the fluid, and put in a new gasket. makes a world of differance on older vehicles.

Thanks. The transmission was rebuilt around three years ago about two months after I bought it (I told you I was putting my mechanic’s kid through college with this thing). It’s got limited mileage on it and should still be in decent shape. I check the fluid level before each use because of the leak.

Thanks for the quick reply. It seems worth a try before I take it off to my local transmission boutique.

well then you probably dont have 25k miles on it since last change. if you try to tighten the gasket, not too tight, and the leak doesnt stop, then the gasket could be sucked into the pan. easy fix, new gasket. could have some gasket material on the pan or tranny surface from the last fluid change.

Use a short handled quarter-inch drive rachet.The short handle will make it harder for you to over tighten.Might work

I hope that they used the original gasket when it was rebuilt or a similar replacement rather than a cork gasket. The original is high quality and reusable. Cork will leak.

I agree with Beadsandbeads about the cork gasket leaking. I refuse to even use a cork gasket due to the fact that some of the cork is of an inferior grade and fluid can actually weep through the material itself. Also overtightening of pan bolts can cause the cork to split; at the time the bolts are installed or later on as the cork ages.
If it has a cork gasket and you change it get either a cellulose or rubberized gasket.

Personally, I never use a torque wrench on pan bolts. The bolts are probably metric 8 MM X 1.25 where they’re threaded into the aluminum case. The best way to do it is to palm a ratchet head (stubby ratchet even better) rather than use the handle. Snug it up with this method and it will probably be closer to the torque specs than a torque wrench would allow; unless you pro wrestle part time.

I did a search on transmission pan gaskets & low & behold found my original post.

OK, It’s a few months later. I tightened the gasket but ol’ faithful still leaks and managed to fail inspection because of said leak. It’s time to change the gasket.

Having never had to do this, is this an expensive repair? Is this something that a “willing to get dirty” but definately low skill level amateur (oil changes OK) can do and save a lot of money or am I better off taking it to my mechanic?