only reverse, transmission problem

[ChristophSchwab]

Hi all,

my 1999 build, Ford Expedition 4.6
with (I guess) the AODE, 4R70W (4wd) Transmission
is (from one minute to the other) only going in reverse, no more "D" movement.

It locks the car in Park position.
It make a "click" and goes into reverse and drive backwards normally
It is fine in "neutral"
shifting to "drive" no "click" and nothing happen....

I checked ATF Level - OK
I checked shifting linkage - OK
I disconnect sensors - than warning lights coming on - OK
I reset Computer - OK

I removed oil pan of transmission and found on the magnet around half teaspoon of metal powder.
Or at least something magnetic, it's like powder, you can't feel any corn.
(sorry for my english, I am german)

The oil itself looks very clean, and dont smell any kind of burned.
The car has only 50.000 miles.

Any ideas how I shall proceed troubleshooting ?
As I am living in a rural area in the Philippines, there is no FORD dealer around.
And if, the are quite clueless here

Thanks in advance for any advice

Christoph

 

[RichardH]

Does the '99 have a neutral safety switch? My '01 has one. It tells the transmission what gear it should be in (R, N, D). If it doesn't get the signal, that 'might' appear to be a potential source. Just throwing it out there.

 

[ChristophSchwab]

after reading me true a million pages, I get to the point, that it must be a mechanical problem. As the way to get pressure to the forwarding clutch is pure mechanical done. Worn out clutch, broken gasket, broken clutch cage etc. So I will need to get it out and see what's wrong

 

[RonB1964]

My 2000 5.4 Expedition does the same thing. If you rev the engine up to around 4000 rpm in drive, you may get enough pressure to engage the clutches. As a temp workaround, change the fluid and add some seal conditioner. While your transmission needs to be rebuilt, you maye be able to run it as I have. I minimize the time in reverse and neutral and have driven my expy in this condition for over 60k miles. Mine has 230k.

 

[1955moose]

Sounds like a failing pump. Either way it's going to have to come apart. You can hook a pressure gauge to the transmission port to check if it's close to spec. The other possibility is you've got a stuck valve body, not allowing it to get forward gears. Let us know what you find.


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[ChristophSchwab]

Hi guys, I did open the transmission, forward clutch burned :-(

 

[1955moose]

If your rebuilding the tranny/ vs replacing it, get a full kit, find out what made the part fail if you can. Replace pump seals, and you probably will want to swap out valve body unless you can r&r it yourself. Let us know how it turns out.


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[ChristophSchwab]

If your rebuilding the tranny/ vs replacing it, get a full kit, find out what made the part fail if you can. Replace pump seals, and you probably will want to swap out valve body unless you can r&r it yourself. Let us know how it turns out.


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I found an complete "premium kit" with all parts for 235US + 70US on ebay, I just ordered it http://www.ebay.com/itm/Ford-4R70W-Deluxe-Transmission-Rebuild-Kit-1998-03-/220723837369

 

[RonB1964]

My 2000 5.4 Expedition does the same thing. If you rev the engine up to around 4000 rpm in drive, you may get enough pressure to engage the clutches. As a temp workaround, change the fluid and add some seal conditioner. While your transmission needs to be rebuilt, you maye be able to run it as I have. I minimize the time in reverse and neutral and have driven my expy in this condition for over 60k miles. Mine has 230k.

I should have updated this year's ago, but the root cause of my transmission issue was a loose center case bolt (which is hollow and is also a fluid feed for the clutches and rotating assy) I had to drop the transmission pan, filter and valve body to expose the loose bolt. I cleaned the threads and added loctite and torqued it back to specs. After putting everything back together, problem solved.