Looking for your collective expertise

2007 E350 with 5.4L and 4R70W trans. 107K miles and the fluid has probably never been changed ( my mistake - thought it was 100K interval - finding out from my reading that is def not true ). Anyway, looking for your advice for the following recent development (last couple days):
Symptom #1: In Park/Neutral there is a whine. As soon as you put it in P or N, the whine 'spins up', stabilizes, and does increase with engine RPM.
Symptom #2: Hesitation (albeit minor) when starting from stop in D and R, with _very_ minor shudder. Sometimes feels like it's struggling a bit to move its own weight just until it's rolling.
Symptom #3: Shudder when accelerating in OD. No shudder when I turn off OD. It does not stop when applying brakes (a test suggested elsewhere). Also, the shudder does not happen when applying gas while braked in D at standstill. Only at highway speeds (enough to be in OD).

This all started at the end of a trip (90 miles or so in 85-90 degrees) when I was pulling a utility trailer (maybe 2000 lbs loaded). Not sure if related,
but traction control warning went off a couple times. I think I have a axle seal leak that may be triggering that.

Otherwise shifts fine (no change in shift behavior or smoothness). Things seem to be worse when it has heated up.

I have not done anything yet, besides reading a lot in various forums. Should I start with a fluid change? Wasn't sure because there are comments out there saying don't do it or the tranny will just fail faster (I am skeptical).

Any help appreciated. I can live with a TC replacement, but hoping this doesn't turn into tranny replace/rebuild or the kids' Xmas might be a little light this year.

 

Change the trans fluid. That might be it. It might also be the spark plugs, or an ignition coil.

 

I agree with changing the fluid but first I would be looking at the engine tune.




Plugs, wires, coil.

Many times this will correct what seems like a wonky transmission.

 

Update. Did full TX fluid changeout today. It misbehaved (slipped/hesitation) a little on first roadtest, but I suspect just needed to get the fluid circulated. The shudder and hesitation from standstill seems to be solved, at least for now (10 miles or so).

The TC whine is still there. I will listen for any odd noises. The pan was pretty clean. Mostly filing/shaving sized debris. The biggest non-filing piece was probably 1-2 mm in size.

I will update here in a few days after some more miles on it. Now need to get into shop for what looks like a bad rear axle seal leak on right side (just had them done 3 mos ago).

BTW if anyone does decide to do this, instructions in the link below were great. Note that if you are doing on E350 (steps are for F150), remove the interior engine cover for super easy access to return line into trans. A little PBlaster took care of the corrosion/rust (upstate NY climate) on the fitting to get it loose.
https://sites.google.com/site/fordf1...nge-procedures