I learned something about changing the tranny fluid on the Navigator that may be of interest to others.

After searching and reading posts on here I got together 18 quarts of tranny fluid plus tranny filter and gasket for my 2002 4WD Navigator. This vehicle has a drain plug in the pan and a rubber plug over the torque converter bell housing.

I pulled the pan drain plug and got a little over 6 quarts of fluid. Pulled the rubber plug from the bell housing and looked for the TC drain plug. And I looked some more. I turned the engine with a ratchet wrench on the front pully bolt. I put a chalk mark on the front pully so I knew when I had turned the pully about half to three quarters of an inch. Then I'd crawl back to the TC and check for the plug (and put a chalk mark on the converter so I would know that that portion of the converter had been checked. I went through TWO revolutions of the crank and NO TC DRAIN PLUG! Whats up wid dat?

Dug out my 2002 Ford DVD service manual and - duh!. I had been reading the portion of the manual that has to do with the 4R70 transmission (which calls for fluid, filter, and gasket replacement). Apparently the Navigator has the 4R100 tranny.

Under the 4R100 transmission portion of the manual it only calls for fluid drain and refill. And it has three sub groups,
Vehicles with a pan AND TC drain plug,
Vehicles with a pan OR TC drain plug,
Vehicles with a TC drain plug and withOUT a pan drain.
(Apparently not all 4R100s are not created the same.)

No where does it say to remove the fluid filter. It actually says do NOT remove OR install a new fluid filter!

Of course these service manuals never say WHY they don't want you to remove the filter. My guess, and that's what it is, my SWAG, after looking at some of the cutaway pictures of the 4R100 tranny, which has a deep sump on the pan, draining causes the tranny fluid to backflush the filter when the fluid drains.

Perhaps someone that has overhauled these transmissions can shed some light on this.

(As an aside, I think that many disagreements get started on this board because of the variations in these vehicles (i.e, plug changes are easy/hard, 4.6 vs 5.4 vs Intech, COPS vs Coilpacs/wires, 4R70 vs 4R100, etc), as some people think everyone's vehicle is the same as theirs).

Thanks for listening.................

 

I know that my 99 Eddy has both drain plugsin it as well as the 4R100 trans. I am not a transmition pro I have worked on few over the years, but I come from the old school of change oil change filter. Maybe it isn't needed I don"t know. I have heard about change filters not screens and so on. I know I feel better when both fluid and filter are changed. The pan needs to be dropped so it can be cleaned and checked for chunky's. Just my $.02 worth.

 

I just read someplace (unoffical, but prolly true ) that if the tranny was built after August 2001 it will not have a TC drain plug.

Omahastro1, I hear ya regarding the oil & filter change. I was just surprised Ford said don't change the filter. I suspect the original equipment filters might just be of a better quality than the aftermarket filters, but hav eno way to substantiate.

BTW, when I dropped the pan I was actually surprise that the inside of the pan was shinny clean after 80k miles, with just a little gary slim coveing the magnet. Especially when the fluid came out a blackish/red color.

 

I have a 2000 Expy 4x4; 4R100 transmission. I changed fluid and filter recently. Drained oil via plug in pan, then dropped pan, removed filter, replaced filter. Then removed rubber plug over torque converter access hole, removed TC plug and drained fluid (takes a long time to drain through that small of a hole, about 1 hour for me.) Replace TC drain plug, rubber cover plug, and then installed pan (gasket is reusable, just clean surfaces and torque the pan bolts to spec.) I also drained the cooler by disconnecting the lines at the transmission. All of the draining doesn't necessarily get 100% of the fluid out, but it gets most of it. Refill with MERCON V bought from Ford parts at dealer (same with filter). Pretty straightforward for me. Not sure why your trans TC doesn't have a plug in it, mine is older and had one, you would think Ford would have kept it in a newer trans. On all of my other vehicles, when there has been no drain plug on the trans sump, I find a kit for it and install one. Just drill one hole and install, allows you to drain fluid only on a regular basis.

 

I'm taking a quess here, but maybe since so many shops now have a tranny flush machine, I think Ford is promoting that approach by not putting in pan drain plugs and TC drain plugs . . . .dunno

 

It's a cost savings thing. It costs them labor time to drill/tap the plug hole in the converter,and the cost of the drain plug itself. Multiply those costs by the number of transmissions that you build every year,and you can see the savings for the manufacturer. They could care less what happens to your trans after the warranty expires.
JL