Synthetic Auto Trans Fluid...Pros and Cons?

[TheKirbyMan]

I have a 1981 F-150 with a 302, C6 transmission, and 9" axle. The transmission has had a pan gasket leak for years, and at some point in the near future I hope to fix this leak, as well as change the filter and fluid. So I'm curious, what are the pros and cons of using a synthetic transmission fluid? Also, will the transmission benefit from it? The odometer reads a bit over 60K; I'm guessing it means 160K, since the truck runs quite well for its age (carburetor issues aside). The transmission has been unintentionally run low on fluid a number of times, but I always brought it back up to level as soon as possible. Any help is appreciated. Thanks!

[Franklin2]

Most all the newer trannies are going to synthetic or synthetic blends from the factory. It's pretty good stuff. That being said, I would not put synthetic in your tranny unless the manufacturer of the oil says it's backward compatible. The tranny is designed around the fluid that is recommended for it. That's why there are so many types of tranny fluid.

So if you find a synthetic fluid that says it replaces dexron/mercon that was originally in your tranny, I would try it. Even when you buy the regular fluid, you have to read the bottle. They have a dexron/mercon I, II, III, etc, but if you read the bottle they say the newest fluid is compatible with the older types usually. That's what you need to worry about whenever changing the tranny fluid.

[TheKirbyMan]

I would not put synthetic in your tranny unless the manufacturer of the oil says it's backward compatible. The tranny is designed around the fluid that is recommended for it. That's why there are so many types of tranny fluid.

Of course. Over the past several years, I've become rather familiar with the different types, since I've had to buy the right kind almost on a weekly basis sometimes. lol

I'll do some looking around and see what my options are. Thanks for the info!