4R55E slipping, any ideas?

[pjm]

Hi, I have a 96 XLT 4WD with a 4R55E tranny. 106K miles on it. 4.0 OHV

Tranny service history since I bought the truck with about 50K miles on it:
Filter and fluid at 56K
Power flush tranny, Mobil1 refill at 85K
Some time after that, experienced the 2-3 shift flare so,
New EPC valve and bracket, Trans Go shift kit, separator plate, adjust bands, filter and refill with Mobil1 at 88K (Nov 04).
No servicing done since then.

Fluid is pinkish brown and full when checked hot, no smell to speak of.

Since the last service the truck shifted better than it ever did until a day or two ago. I thought the flare problem was back on the 2-3 shift, but today I realized that when on the highway and step on it, it freewheels and revs high with no forward to speak of. Back off the gas and baby it, and it goes ok. Then I noticed that almost all shifts, under load, seem to be slipping a bit, like the flare problem but getting worse. No codes have been thrown for this, but had one for a P0304, 4 cyl misfire. Cleared that and ran some Seafoam through, and no recurrence so far.

I know there's a lot of knowledge on this forum, would appreciate any help or pointers you could provide. Really don't have the budget to replace a tranny right now - TIA.

Non-standard items: Bama chips 92 performance tune, KKM, BBK, Flowmaster cat back.

 

[pjm]

Hi, I have a 96 XLT 4WD with a 4R55E tranny. 106K miles on it. 4.0 OHV

Tranny service history since I bought the truck with about 50K miles on it:
Filter and fluid at 56K
Power flush tranny, Mobil1 refill at 85K
Some time after that, experienced the 2-3 shift flare so,
New EPC valve and bracket, Trans Go shift kit, separator plate, adjust bands, filter and refill with Mobil1 at 88K (Nov 04).
No servicing done since then.

Fluid is pinkish brown and full when checked hot, no smell to speak of.

Since the last service the truck shifted better than it ever did until a day or two ago. I thought the flare problem was back on the 2-3 shift, but today I realized that when on the highway and step on it, it freewheels and revs high with no forward to speak of. Back off the gas and baby it, and it goes ok. Then I noticed that almost all shifts, under load, seem to be slipping a bit, like the flare problem but getting worse. No codes have been thrown for this, but had one for a P0304, 4 cyl misfire. Cleared that and ran some Seafoam through, and no recurrence so far.

I know there's a lot of knowledge on this forum, would appreciate any help or pointers you could provide. Really don't have the budget to replace a tranny right now - TIA.

Non-standard items: Bama chips 92 performance tune, KKM, BBK, Flowmaster cat back.

So latest chapter after reading all the great advice in this forum was to bite the bullet, take it to Ford to have the DTC's read by a Ford NGS scan tool. For $150, I found out that there were no dtcs for the tranny that Ford could see either. Of course, they then recommended a new tranny (which they quickly admitted was reman when I asked about it) for the low low price of $3500, installed.
Before I call and order a rebuilt tranny from Phoenix or Roadmastertrans, is there anything else I should try??? That's still going to be $1000 but maybe it's worth the peace of mind. I plan on driving the trucck to 200K miles if the engine lasts that long.
Any advice on this would be greatly appreciated. I'll also search for a good thread for tranny R&R, especially any flushing necessary, but if you could point me in the right direction that would be great too. I'm fairly good with a wrench and assume I could do this in a weekend or less... again, thanks.