Hey gang,
I have a Super Duty with the 5.4L engine. I want to replace the transmission fluid with Amsoil and was wondering if it's even possible to completely drain the transmission and completely replace it with pure synthetic. I see some other posts explaining how to do it and I'm ready to get dirty. Any pointers? TIA

 

You have a 4R100. If it's not giving you problems now, leave it alone. With a synthetic fluid it may be more prone to shudder.

 

the 4r100 will be more prone to shudder. with a synthetic fluid. i won't even go into the amsoil debate.

 

pfogle,

How can you be sure he has a 4R100? My 2004 E350 with 5.4 has a 4R75 according to the data plate. Unless Ford just developed the 4R75 in the last 2 years I would expect all 5.4s to have the same transmission. Also, why does synthetic cause shudder?

 

Syntethic will NOT cause the 4R100 to shudder. MERCON V will screw up the trans, and that includes any fluid that has both MERCON and MERCON V ratings.

Many people believe the MERCON is non-synthetic and MERCON V is synthetic. That is not true. You can buy either MERCON or MERCON V in conventional, blend, or full synthetic.

I use Mobil 1 synthetic ATF in my 4R100. It has a MERCON rating and no MERCON V rating, so it is fine in the 4R100.

As for which trans island-guy has, check the blue tag on the driver's door jamb. Under the letters TR is either an "E" or a "U." If it's an "E" it has the 4R100. If it is a "U" it is the 4R70W.

The 4R100 requires MERCON and the 4R70W requires MERCON V. It also will say which fluid on the transmission dipstick handle.

Ford stopped installing torque converter drain plugs very early in the 2002 model year, so chances are you don't have one. There is a better way to change the fluid, though. Read this:

https://www.ford-trucks.com/article/...nsmission.html

 

so what fluid is used in a 05 f250 6.0l

 

can a transmission from a 03 e350 5.4l van fit a 00 f 150 5.4l

 

It can use either MERCON SP or MERCON LV.