Yet again Expedition woes

[Ozwynn]

I had to drive the expedition today because my wife needed to go the opposite direction so she took the excursion. I was driving to school at 8 oclock this morning and made it 10 miles to the first stop light I come to. sitting there I was feeling the transmission tug against the brakes like usual..... then there was a buzzing like a buz saw going through lumber for 10 sec then no more tug. like I shifted into neutral... and no more buzzing. cycling through all the gears there is nothing. some guy with an ecoboost F150 pulled me into a parking lot. I shut the engine off and let it sit. started it after 5 min and I put it in drive and it moved under its own power really strong like noting happened. after 100 feet it started buzzing again and stopped.

could this be an electrical problem cause by my dried out nasty corroded previously waterlogged body control module?

Also, I have an un explained coolant loss. been loosing coolant for the last 3000 miles with no visible leaks and no coolant in the oil..... maybe its going into the transmission via the transmission cooler? I check the fluid level and it was a qt low, clean, not burnt, and did not smell like wood chips. but i will drain it tomorrow afternoon and see if any coolant comes out.

 

[adsm08]

If you have an oil pressure gauge get it on the line-pressure port (I think it is the forward most 11mm plug on the DS of the case) and see what is happening to the fluid pressure.

Also, check the fluid again, but wipe the dipstick on a clean white rage (yes, color is important). If there are small metal shavings in the fluid the spot will turn black. If you can catch it while it won't engage check the fluid while it won't grab.

If I had to guess I would say the converter hub is partially stripped. Evidence to support that idea enough to justify pulling the trans is what I am looking for with those checks.

Loss of fluid pressure or rising of fluid level when it won't engage means the pump has stopped working. If the pump stopped then you either lost it's input or the converter hub.

 

[Ozwynn]

thank you sir..... it will be dark before i get home tomorrow but I will get right on that thursday....

how much line pressure should I be looking for with an oil gauge? is that a 1/8th npt for that port?

 

[adsm08]

Test in OD or D

30-70 at idle, 160-210 WOT if you have a 4R70W

50-65 at idle, 165-185 WOT if you have an E4OD.

Not really sure why there is a distinction, they are almost the same trans. I think it's a 1/8th NPT, but I am not good with NPT sizes nor am I really a trans tech. I kinda know how they work and I can take the pan off, see it's full of metal and say "Yup, she's toast. Let's price a new one".