4R55E trans issue

[ThreeJs]

Thanks in advance for any answers anyone can give
Back story.
Bought used 2-3 months ago. Unknown history. 1996 Explorer EB, A/T, 4x4, 4.0 OHV, 134K miles. I had the 2-3 shift flare problem and then later, slow to engage reverse. Driving home one night my O/D light started flashing and it didn't seem to want to shift to 3rd. Playing with the throttle it finally shifted up and we got home. Started the next day. O/D flashing was gone and it seemed OK. Parked it.
Did some research on 4R55E/5R55E trans problems and decided to try the valve body separator plate gaskets.
Further research and decided to replace the electronic pressure control solenoid also.
Upon teardown, the VB gaskets seemed to be OK with no visible blown out gasket areas. Replaced VB separator plate gaskets, EP solenoid, pan gasket/filter, filled with Mercon V and 1 Lucas trans additive. Cleared codes, just in case, so computer was starting fresh after the work done.
Now trans shifts better but only under light throttle. Easing into the throttle the trans seems to shift fine with no flare issues. Problem is under heavier throttle, acceleration from a stop into faster moving traffic, the trans will not shift into, I think, 3rd and the O/D light starts flashing.
If I pull over and shut it off and restart it will shift fine, again under light throttle.
Scanned for codes but found none?
I am dropping it off at a shop to have them take a look/ test drive/ scan.
Any suggestions as to what I may be looking at? Solenoids, bands, servos???

 

[ThreeJs]

scanned and found a PO733 code.

 

[JK080]

The direct drum inside the transmission is used in both third and reverse, and the code is for gear ratio error in third. With all that you have done so far I think the problem is going to be inside the transmission and associated with the direct drum.

Servos and the bands are not used for third gear and I doubt the solenoid is the problem. You can swap the solenoid with another one on the valve body and see if the problem changes but its a long shot.

 

[ThreeJs]

The direct drum inside the transmission is used in both third and reverse, and the code is for gear ratio error in third. With all that you have done so far I think the problem is going to be inside the transmission and associated with the direct drum.

Servos and the bands are not used for third gear and I doubt the solenoid is the problem. You can swap the solenoid with another one on the valve body and see if the problem changes but its a long shot.

Ordered a new BWD shift solenoid through work. Was able to get the price down, Figured $25 was cheap enough and worth a long shot. I should be replacing the Shift Solenoid 3, correct?
SS3 is on the opposite side of the Torque Converter Clutch Solenoid. Towards the front of the vehicle and on the side with two solenoids with the rear being SS1.
found a pic
http://www.justanswer.com/ford/6ao8p-ford-explorer-codes-po-761-shift-solenoid-c.html

What really blows is I gotta get another Lucas and 8 quarts of Mercon V. I'm not cheap, but Mercon V @ $5.00 a qt hurts my lunch money funds, lol. I don't think I can try to save the fluid when I drain it again and in reality it's not worth it.
I guess my trans is just getting a good flush.

 

[JK080]

Ordered a new BWD shift solenoid through work. Was able to get the price down, Figured $25 was cheap enough and worth a long shot. I should be replacing the Shift Solenoid 3, correct?
SS3 is on the opposite side of the Torque Converter Clutch Solenoid. Towards the front of the vehicle and on the side with two solenoids with the rear being SS1.
found a pic
http://www.justanswer.com/ford/6ao8p-ford-explorer-codes-po-761-shift-solenoid-c.html

What really blows is I gotta get another Lucas and 8 quarts of Mercon V. I'm not cheap, but Mercon V @ $5.00 a qt hurts my lunch money funds, lol. I don't think I can try to save the fluid when I drain it again and in reality it's not worth it.
I guess my trans is just getting a good flush.

SS3 is not for third gear, matter of fact no shift solenoid is on for third gear.

For first gear just the SS1 is on, for second the SS1 and SS2 are on, third gear is all solenoids off and for forth gear just the SS3 is on. So to try to make a difference with the 2-3 flare maybe change the SS1 or 2, they have to turn off for third.


I would try to save the fluid and reuse it until you get this problem straightened out, you may be pulling the pan again or removing the unit in the long run so it just seems like a waste of oil and money.

 

[ThreeJs]

Thanks. Haven't had a chance to get the Ex to the shop. Been driving it all week and it's been shifting OK. Only once has the O/D light started flashing. Stopped, restarted, light went off and was shifting OK. I just keep a light foot and try to baby it and it shifts fine with no shift flare.
Still have the solenoid on hold, haven't billed it out yet.
I guess I'll keep driving it for now till it becomes more of an issue. I'm planning on a trans build in the back of my mind though.

 

[ThreeJs]

Had trouble a couple of days ago but it did shift into 3rd, OD started flashing, and drove normally after 3rd gear. Well, the trans has pretty much stopped shifting into 3rd gear. Trans will shift into 2nd with no issues but 3rd just doesn't seems to come. Engine will rev to 3K+ rpms at 40-45 mph. Letting off the throttle and reapplying does nothing. Drove home in 2nd @ 35 mph on side streets. OD light did not flash after restarting. Backing into the drive reverse was very slow to engage and harsh when it finally did engage, OD started flashing and it did shudder.
So..this sounding internal??
Opinions/guestimates on cost of a rebuild on a 4R55E trans and what might to be replaced?