Re-use the bonded separator plate on a 5R55E? [With mileage updates]

[Fredness]

12 years and almost 100,000 miles later...
P0732, P0735, flashing "O/D OFF", and 2-3 flare.

 

[CDW6212R]

That's a good update, well done. If you go back into it, this time you might install a couple of set screws up into the passages of the case, above where the gasket is prone to blow out. Those passages are very deep, so as thin as the walls are, they can be forced to move, side to side, which is the main cause of the gasket issues there.

 

[Fredness]

[June 5,2022 update reply - see above]

The 2/3 flares, and 5th gear slipping turned to be the OD band adjuster backed off.

Local "experts" refused to even look at the band adjustments saying if it slips the band is done.
I tightened it to spec (in the middle of a move with all my specialty tools packed) and we're now at 215,000 miles.

Planning on a complete rebuild, this time on my dime and not just a bone stock build.

 

[Fredness]

No issues since June 5, 2022 - Now at 226,x.. miles.

December 2023 - O/D Off flashing on a cross-country trip .
Code is TC lock/unlock issue.
While not fatal, having this error is near fatal to me (800 miles from home, and no shop on the homestead).

Nearest shop was a Firestone in Arkansas and they were packed - I told them I had 2 concerns:
Transfer Case Level
5R55E venting high pressure ATF at 80mph in the mountains.

They found everything was OK, but the trans was a "quart+ overfilled" - no one touched it (with my knowledge) and the trans was "between the lines" before our 2,200 mile trip, I had changed the external trans filter (prefilled with fresh MERCON LV as it was all that was available - <1QT), trans fluid level checked warm on flat ground before we left.
They showed me what was going on (ATF from the vent back to the rear bumper on EVERYTHING), and discussed how to remedy (all labor intensive). I said drop the (new) external filter, drain, repeat - since I converted to "Full-Flow" with an external thermostat, the filter fills instantly.
2 drain cycles needed to get back to correct level (Mobil1 M301A), and after hitting a carwash with an "undercarriage" cycle, we were all set.

Venting stopped, but the O/D OFF flashing issue remains, along with the code.

Here are my thoughts (I welcome opinions):
TCC Lockup is hit and miss, at 80+MPH the TC isn't locked, creating excess heat INSIDE the trans (Fluid looks like new, no smell), and that pressure blows out the vent, the remaining fluid is cooled by the MASSIVE external cooler and returned - but the heat (and possibly the 1QT of "Low Viscosity" Fluid) may be causing expansion/aeration of the fluid, making it LOOK like it is overfilled.
That's my theory anyhow.

But I've swapped strategies.
The 5R55E will be babied until I can have an alternate vehicle @100%.
Then:
V8/4R70W/AWD swap timeline gets shifted to the left of the calendar.
Later the AWD to BW4406M swap, once I have all the parts (Swap was going to be everything at once).
5R55E gets gutted/rebuilt, receives extra clutches, new frictions, and a 4R44E bellhousing to go behind a 2.5L (for the Foxbody swap).

 

[CDW6212R]

How old is the TC solenoid?

 

[Fredness]

TC Solenoid was replaced and new VB separator plate installed about 2 years ago when I was having issues - went through the Ford Diagnostics, replaced all the parts listed to rule out the Torque Convertor - it's probably the TC.

 

[CDW6212R]

Yeah, the solenoids are easy and with age prone to be the issue. Then yes the torque converter is sadly a possibility. It reminds me of my rear seal, it's been leaking more lately so R&Ring the engine or trans is a big deal.