I've noticed a weird phenomenon on our 4x4 99 Exped. There is a driveway to a business in town here I had to get into a couple days ago and couldn't. It is a very steep driveway with a right hand corner. I got half way up, and the Exped stopped moving. Letting off the throttle results in a quick backward decent, of course...but keeping throttled up only keeps the vehicle in one place...the wheels stop moving. This is in auto 4wd and Drive, with OD on or off...doesn't seem to make a difference.

In 2nd or 1st, the Exped goes right up the driveway, no problem...but shouldn't my auto trans be doing this for me? Granted I didn't step all the way down on the throttle to get it to downshift for me...but that would be dangerous anyway as it is a pretty tight driveway...don't need to be interupting anyone's lunch by caving in a wall!

So my questions are: Is there possibly a line pressure problem here within the trans that isn't allowing it to lock the converter and thus keeping the vehicle from climbing the way it should? Is this a sign of worse to come? Or totally normal wear that just needs a tq converter adjustment/band adjustment, or line pressure modification? The Exped has 152,000 miles on it.

Thanks all! I also posted this in the Expedition forums...didn't know which would get more attention!

Sam

 

Well first off what does the fluid look like? And second your speed needs to be going fast enough to actually activate the converter clutch & lock the converter in which is ONLY in the overdrive gear. If it stops at a point like you mention, you may just be in need of a overhaul.

 

Another thing can be that rear band needing adjustment like you mentioned BUT if the fluid is dark and a fluid change does not do anything you will be needing an overhaul for sure since you have 150,000+ Also if you hear anything about other transmission torque converters locking up in 3rd gear and they are a 4speed, that is also possible. But as for now try the band adjustment and fluid change. I still havent studied on this larger heavier duty transmission yet which I should do soon, I am slackin here.
Good luck hopefully its just a band adjustment and/or fluid change.

 

Band adjustment on a 4R100? No, not possible.

 

So are you saying there is not adjustment for the band and just a R&R procedure? because there has to be a rear band to hold the rear clutch drum though for shifting into 4th correct? I would like to know.....

 

The only band in the 4R100 is only used when the shifter is in the 2 position. It provides engine braking when the shifter is in 2.

The overdrive clutch is used to make fourth gear, and it's towards the front of the trans.

 

Interesting discussion fellas! The fluid isn't bad at all in it. Doesn't smell at all. Not quite new looking, but not burned by any means. It is also retaining its lubricity, which I always check by rubbing the fluid between my fingers. If I can feel my fingerprints, that is bad to me...which I cannot...it is still very slippery feeling.

Basically this is starting to sound like I need to get the fluid and filter changed, as a preventative measure (never hurts). Also sounds like maybe she was just too heavy for that Drive gear (3rd/4th) on the hill I was on, rolling as slow as I was...and maybe just maybe, since 1st and 2nd did produce a positive hill climb, it just needs a bit more line pressure while that converter is in fluid mode rather than locked?

Dunno, my auto trans knowledge is minimal really...but that is what I'm gathering thus far. Fluid/filter/shift kit

Thanks guys!

Sam

 

Hmmm interesting, is this system also used in the 4R70 also then? and is there a picture of the internals somewhere on this site or should I just try n find a book to buy on this transmission?

 

OK, under the assumption that I have the 4R100 for sure because it says Mercon, not Mercon V fluid. HUGE rectangular pan with a valley where the drain plug is. I'm going to go for drain and refill. The fluid was plenty full.

ALSO, my dad did some work to the battery cables BEFORE this problem...read: He had it unplugged...so could have been a case of the computer relearning as well. Didn't think of that until just now.

 

Yeah, I am thinkin if it is a huge pan you probably have a 4R100. You can call a Ford dealer to verify it by telling them your VIN. Remember since this trans is fairly large I am guessing close to 1 gallon of fluid in the torque converter alone. So you will not be getting every once out by dropping the pan but you are still changing a good amount of the fluid.

 

Right on...drop the pan, find drain plug in converter and drain that too...doesn't look like a huge job under there. Not like our Yukon anyway where we had to unbolt the entire exhaust system to access the trans pan. This looked like every bolt is exposed.

 

from what I could tell crawling under and in the snow...looked like this one.

http://www.FTEs diesel forums.com/projects/e4od/163.jpg

...but with a drainplug.

 

Yeah, I did some research and the 4R100 has 20 bolts around the pan perimeter. Also shares the pan with the E4OD.

 

Yep...so can't even tell them apart then, though from what I know, the E40D didn't have a drainplug from the factory. I'm also told the E40D takes Mercon V...but I could be wrong there as well. I guess a call to the dealer is the easiest!

 

No, the 4R70W is completely different. It does have an overdrive band, but it is not adjustable.

I don't know where to find a picture of the internals.