Need Tranny Help

[HTRDDSL]

Today I went for a drive and on my way home my tranny gauges, factory and aftermarket went into the red zone. I wasn't doing anything unusual and only noticed it when I was almost home. I checked my tranny and ended up putting about 2 quarts of fluid in there. I checked it two weeks ago and it was fine. The fluid is still nice and clean. I started up the truck after it cooled down and let it run for awhile. With the factory gauge in the normal range and the Autometer gauge showing 125F I put my hand on the tranny lines going to the cooler. They were still cool to the touch. The truck was still shifting and operating fine the last few blocks home. I'm still under warranty as I purchased the extended warranty when I bought my truck. It's a 2002 F250 Diesel with the auto tranny. I haven't taken it out since I added the fluid and I don't know if I should. I've never had any problems with the tranny before. Any ideas/suggestions are most welcome.

 

[RickGmi]

You mentioned that you only went to the store, that might not be enough driving for a good tranny fluid check, the tranny fluid will show low when the tranny is still cold, the book suggests driving 15 miles then checking, that way the tranny is warm and the fluid has exspanded to the fullest mark,
Im wondering if your problem is more in the gauges then the tranny, since you mentioned lines are cool, You might want to put a few miles on the truck then check tranny level to make sure you hav'nt over filled it, I believe that tranny has the fluid go back into the pan when not running, which would give you a high mark on dip stick, then when you first start it that tranny fills all the pressure lines and once warmed to temperture it expands the fluid which would read the true tranny level on the dip stick,

Have you pulled any codes on the tranny, you might want to check that, if the tranny has a problem your OD light on the shift handle will blink telling you that you do have a tranny code,...if you have someone with a 1795 super chips it will pulll some tranny codes

 

[HTRDDSL]

Actually I never mentioned going to the store. I went for a drive( about 35 miles) prior to the overheating problem.

But I think I may have found the problem. It's fairly cool today and with the fluid temp level okay I went for a drive. After about 15 miles my autometer gauge was around 170 which is high for the cooler I'm using. I drove home and got under the truck. On the side of the 4R100 trannies is a cooler bypass valve. it's designed to bypass the fluid at first start up or when it's cold to help the tranny warm up faster. When I got home I checked the lines to the tranny cooler. both were cool to the touch. Then I checked the cooler bypass valve and it was hot. A good indication that it is bypassing the fluid. The valve is actually a tube about 15 inches long that connects to the inlet and outlet lines of the tranny. I put a link here for anyone who may encounter the same problem. I've ordered a new one and it will be in on Monday. So I will post after that to let you know if it corrected the problem.

Here's the link.
http://www.dieselsite.com/index.asp?PageAction=VIEWPROD&ProdID=172

 

[HTRDDSL]

Well the valve didn't cure the problem. I took it to the dealer and the shop foreman informed me today that it was a sticky part in the front pump. My truck has a premium warranty but because I have modified my truck they may not warranty it. Even though the mods have nothing to do with causing the problem. Ford is sending someone over on Monday to look at it. I should know something by either Monday or Tuesday. The shop foreman who treats me pretty good is going to fight Ford for me but he told me they look for any excuse not to pay on warranty. I'm not optimistic.

The sad part is the tranny is shifting perfectly and even after the teardown all the parts/clutches etc were in perfect condition.

 

[HTRDDSL]

It was definitely the front pump. Ford is covering the repair which is great.