Transmission Interchange 4R75W question
 

Hi. I have an 05 Expedition 4WD with 98K miles. The transmission appears to be toast. BTW, its had two fluid changes since it was new. Anyway, its offical. Every ford I have owned has crapped out a transmission pre-maturely. Its a grocery getter, no hard use at all. So, if I dont fill it full of explosives and push the button or shoot it with all the ammo I have saved up for the end of the world, I have to replace the trans.

I would like to put in a 6R75. Be nice to get that "new upgraded" feeling instead of the "bent over by Ford again" feeling if Im gunna dump $3K into a $9K vehicle that cost over $40k.

Does anyone know if the 4R75W and 6R75 can be interchanged? I am assumming new computers are needed. Im am wondering about the mechanical interchangeablity. And anything else.

Thanks!

I'm da guinea pig then, huh

Guess so,let us know how it turns out.
4r70w/4r75w can be built pretty stout.

If your power levels are stock and your
always having tranny issues,then there
may be other issues to address.

I have been researching this. Its actually quite common to loose forward gears in the 4R75W. The "E" too. Its common for a thrust bearing to go out in the gear train and take out the planetary gears and distribute metal chunks throughout. It is also common for forward drum to just spit. Doesn't matter how well you take care of your transmission, or how many miles on the vehicle. These are design and material defects. Its a total crap shoot. You could be in the middle of the dessert with your family on the way to Disney and your F150 or Expedition will leave you for the buzzards. You like your Ford Truck? Do you feel lucky? Do ya? I have had enough. I just want it out of my site.

But the wife likes the vents and power 3 rd seat....nahh nahh nahh Ugggh. Shes getting a frkin Prius now

You really should familiarize yourself with
the trasmission prior to bashing it. I have
personally put over 800hp through a 4r70w
for over 3 years on a 3500lbs Mustang,not
an issue...words on the web,hold nothing
against real world situations. The 4r70w is
a stout tranny.

Expy is putting down over 400hp and over
500tq,no issues. Yes,also on a built 4r70w.

I say move on.Your obviously not interested
in a ford,and ready to bash them,so dont let
the wife control you. Do what you want.

The bearing issue is for 2010-2011 model years. What is the transmission doing? It may only need a few seals and clutches to be good as new. Just because the trans has a problem doesn't automatically mean install a reman. A good trans tech can pull and overhaul a 4R70W in a day. They are very good transmissions I have almost 200k on my F150 and my mom has 220K on her expedition neither one has had trans problems.

Its a 4R75W. Every transmission place I have called is EXTREMLY familiar with it. Keeps them in business. 2005 was the first year. There are TWO common failure modes. I got plenty of data points that designate this transmision a piece of shiit. Good luck with yours!

Lost all forward gears

The 4R75W is supposed to be a beefed up version of the 4R70W. 2005 is the first year of the "upgrade". They added more electronics in this version. Soooo, I was hoping it was an electronic malfunction. I have checked all the solenoids. I got a new TPS for the throttle body cause it was throwing codes. The screws broke off in the TB housing when I was trying to remove them, so now I ordered an all new complete TB. The trans uses data from the TPS, so I am hoping.....
There is a tail shaft speed sensor and turbine speed sensor. They are just hall effect sensors, I doubt they are the cause.

I removed the pan. There is metal powder, but this seems normal to me. No big chuncks or anything. I will change the TB, filter and fluid and see if that does anything. If I have foward gears, it will go straight for trade in, if not, I will replace the trans and keep it. No choice really. Actually, it has been a good truck otherwise. Too bad.

Yeah, So I finally tore down the transmission to see whats up. Indeed the cause of "No Forward Gears" is a split forward drum. It split where the clutch retaining clip fits into the groove of the "stamped" forward drum. Its a fatigue failure. Fricken Ford! This is unacceptable! The rest of the trans looks immaculate. It probably has 80000+ miles left on the wear items. I need a replacement part, but I don't want to put the same crap back in. I need an updated, stronger part. Anyone know if there is one? I don't think the older cast iron drums will interchange. Not sure though.

You might PM Mark Kovasky, the Ford tranny guru here that could probably help.

I found the replacement drum. 6L3Z-7F207-A I'm not sure what Ford did to it. Hopefully it is a lot stronger. Its used in the current transmissions.

The design might not have changed at all. Your original could've had a flaw that led to it's premature failure.

If the part number changed, the design changed, thats how it works. This is a common failure. If you have an '04, '05 or '06 4R75W or E transmission, you are doomed. Its, not if it will fail, its when. Trust me, I done the research. And there is little warning. At first, it goes into neutral when you are stopped, the motor revs and then it will catch when you try to take off. It will only do that a few times then it will drop you where you are at with no forward at all. You can drive in reverse tho. Its how I got it home.

Also, there is thrust bearing in the planet gears that comes apart. I believe this is on higher mileage units. Anyway, this tears up and strips out the planetary gear assembly. Maybe it makes noise as a warning. The one in my transmission was fine. But it only has 97K miles.

Nice, huh. You like your Ford Truck? Do you feel lucky? Do ya? Pack lots of water if you are driving across the desert. Need a winter survival kit if you are driving across northern states. Dont drive thru the inner city unless you belong there.

I must've missed the part where it was said that the part number changed. Perhaps you could point it out? :-X18

Sorry bout the confusion. I was trying to document the replacement for anyone else with this problem. Should save a couple days of searching.