4R100 overfilled = problem?
I had the tranny fluid changed about 6K miles ago. a few days ago when i shifted into Reverse i had no Reverse. The trans temp gauge said about 150. I know there are issues with weak Reverse in the 4R100 (i've read about it here on the forum). I sat there a minute, tried Reverse a couple more times, and finally was able to get it to grab enough to ease it back. I saw a bit of fluid dripping from the back end of the tranny (not much). I had it examined by a mechanic, and he said the tranny was about a quart overfilled. He said the fluid came from the breather tube on top. He drained about a quart, and now the dipstick shows proper level at hot and cold. I'm an idiot for not asking about the high level of fluid on the stick previously.
I haven't been able to recreate the problem exactly, but i can still feel a little "shudder" in Reverse, especially if i'm backing up a slope.
Question: what's the danger with overfilling? I've read (here also) that overfilling can lead to foaming of fluid and loss of lubrication and cooling properties of fluid (due to being foamed up).
My fluid didn't smell burnt, and looks normal to me. I have an appointment with the Ford dealer in a week to have the tranny checked out. I still have a few months of warranty remaining.
Last edited by samiam; 08-18-2010 at 05:51 PM.