Overfill you Tranny?

I have '02 Windstar and a '03 Taurus. When I got the windstar, my friend said he was told by someone at a ford dealership (I believe, don't quote me...) to just add an extra 1/2 quart of fluid when it was changed and that would prevent (or at least aid in preventing) some tranny problems. This could be done instead of adding an external cooler.

What I am wondering is: what are the rammifications of doing such a thing? Also, would I be better off in adding an aftermarket cooler to 1 or both of my vehicles?

Z.

The person at the Ford dealership might have been referring to a TSB that calls for the ATF to be increased to the top of the hash mark on the dipstick rather than the middle range. This was a fix to decrease harsh 1-2 shifts. But it still had you remain in the hash range on the dipstick, just at the very top mark.

I must admit I tend to keep *all* engine-related fluids at or near the "full" line. Yes, I know overfilling can cause problems - but problems caused by low fluids seem to happen far more often.

Quick example: The Duratec V6 in my '95 Contour is noted for oil starvation on long, right-hand curves. The simplest fix is to keep the oil level on the high side (some recommend a slight overfill).

Regarding auxiliary transmission coolers and the Windstar: I tow a popup camper with my Windstar and added an aftermarket cooler. Interested in the installation? Take a look at the last 6 pictures in this album:

http://community.webshots.com/album/549196858rbUAlb

I must admit I tend to keep *all* engine-related fluids at or near the "full" line. Yes, I know overfilling can cause problems - but problems caused by low fluids seem to happen far more often.

Quick example: The Duratec V6 in my '95 Contour is noted for oil starvation on long, right-hand curves. The simplest fix is to keep the oil level on the high side (some recommend a slight overfill).

Regarding auxiliary transmission coolers and the Windstar: I tow a popup camper with my Windstar and added an aftermarket cooler. Interested in the installation? Take a look at the last 6 pictures in this album:

http://community.webshots.com/album/549196858rbUAlb


Excellent docs on the tranny cooler. Would you recommend one for someone who doesn't tow anything, or at least doesn't tow anything any significant number of times? (I have a utility trailer that I have to take to the dump, that is about all I would tow at this point)

Z.

The person at the Ford dealership might have been referring to a TSB that calls for the ATF to be increased to the top of the hash mark on the dipstick rather than the middle range. This was a fix to decrease harsh 1-2 shifts. But it still had you remain in the hash range on the dipstick, just at the very top mark.


Other that it being bad, what would happen if you overfilled? (the oil for that matter too?) It seems to me it would just sit in the pan. (I admit to knowing very little about the actual functioning of a modern engine.)

Z.

Excellent docs on the tranny cooler. Would you recommend one for someone who doesn't tow anything, or at least doesn't tow anything any significant number of times? (I have a utility trailer that I have to take to the dump, that is about all I would tow at this point)
Z.

I have both a utility trailer and a popup camper - and I must admit that I didn't install the transmission cooler until I got the popup camper.

That said, the weak link in most minivans is the transmission. Based on what I learned when doing research to tow the popup camper, I'd recommend an auxiliary transmission cooler for anyone who's concerned about the life of their minivan transmission - even if not towing! Installing a transmission cooler is a fairly straightforward DIY job, and the cooler doesn't cost very much.

Other that it being bad, what would happen if you overfilled? (the oil for that matter too?) It seems to me it would just sit in the pan. (I admit to knowing very little about the actual functioning of a modern engine.)
Z.

I know that the primary danger of overfilling an engine is that the oil level in the crankcase will get so high that the bottom of the spinning crankshaft will hit the oil, causing foaming (air bubbles in the oil). The force of the oil hitting the crankshaft can cause problems at high RPMs - at the same time the air bubbles are reducing the effectiveness of the oil's lubricating properties.

I'm less certain what the real danger is if an automatic transmission is overfilled. Anyone with more knowledge on this topic?

I know that the primary danger of overfilling an engine is that the oil level in the crankcase will get so high that the bottom of the spinning crankshaft will hit the oil, causing foaming (air bubbles in the oil). The force of the oil hitting the crankshaft can cause problems at high RPMs - at the same time the air bubbles are reducing the effectiveness of the oil's lubricating properties.

Important to know. Thanks.

Z.

zombie13 -

Quick Googling came through...

It looks like overfilling the tranny has similar concerns to an engine: Things hitting the fluid that shouldn't, causing foaming. Take a look at item 8 in the "Don'ts" section of this:

http://www.enjoythedrive.com/content/?id=24194

Someone claimed that another cooler, in addition to the stock tow pkg one will restrict flow too much - others claim they have added another.

Is it a problem or not? If not, I plan to put one in.

Thanks

If the size of the lines in the additional cooler are at least the same as the rest of the original cooling system, there's minimal flow restriction. Note that the Ford OEM tow package for the Windstar adds a cooler to the system, so it's designed with this in mind.

I added a transmission cooler to my Windstar; it works fine. There are some pictures of the project in this album (also referenced earlier in this thread):

http://rides.webshots.com/album/549196858rbUAlb