The tranny shop who rebuilt my transmission supposedly installed a Mag-Hytec pan for me. Unfortunately, they're lying pieces of (insert word of choice) and installed a PML cover instead. I don't want it . . . and it only holds +2qts. I have a Mag diff cover and I've been vary happy. Therefore, I'll be purchasing a Mag tranny pan too. Actually, the tranny shop will be buying it, but that's beside the point. My question is this: Mag makes two styles of pans, one that holds +4qts and one that holds +8qts. My first instinct was to go for the +8, however, there must be a point when more fliud doesn't necessarily cool any better. Also, will 8 more quarts of tranny fluid hurt my tranny? Should the +4 be sufficient? Apparently, the +8 does not obtrude from the bottom of the truck, so it's not likely I'll hit it on anything, FYI. Also, I don't do any heavy towing with my truck, just some quads every now and then. My vehicle also has the factory aux cooler.

-Craig

 

Yes, that point exists. It's at zero quarts.

More fluid won't cool the trans any better. A bigger cooler will cool the trans. A larger pan looks good and costs more $$$ to fill, but it won't cool the trans.

More fluid will take longer to heat up, but it will also take longer to cool off once it is heated.

 

Actually, the fins on the bottom of the cast aluminum pans do help disipate the heat from the fluid better, thereby cooling the trans.

Since you don't do any significant hauling/towing, the +4 qt pan should be more than adequate for you.

 

I guess my real question is whether or not holding 8 additional quarts of fluid will harm my tranny.

 

Additional fluid won't harm the trans, unless you frequently drive somewhere that's VERY cold. Then the trans won't heat to normal temps, and that's not good for it.

As for the fins dissipating more heat, I don't buy it. There is no cool air under a truck. The exhaust is there, the heat from the radiator is dumped underneath, etc. You can't dissipate heat into a hot environment.

I believe those pans are all for show and making the owner feel better. I do not believe that they help cool the trans at all.

 

While the vehicle is moving large amounts of relatively cooler air are moving beneath the vehicle. The fins increase surface area, which allows the heat energy to transfer to the air. This is the same principle as why the block of lawnmowers are finned. The finned pan obvioulsy won't make as much difference as a tranny cooler, but it will make a difference - unless the vehicle is sitting idling. Then I believe you would be correct in your analysis; however, then the tranny wouldn't be creating heat either...


As far as 8 qts harming the tranny, it shouldn't as long as the pick-up is still at the bottom of the pan.

 

Thanks for the responses, fellas. Whether or not a bigger pan makes a difference is beside the point now. I've already paid these guys $275 for a pan that costs $175 (the PML). They won't give me a refund, but they will exchange the one they put on for a Mag-Hytec, which is about $250 . . . although the shop would probably charge me $400 for it. Since I live in Washington and it has been known to get fairly cold around here, I think I'm going to get the +4 pan.

-Craig