P0741 & P0735 - TCC Solenoid Replacement + Fluid Service (2007 Expy 5.4L, 6R75)

[whySKIPdodis]

Hey everyone,

My 2007 Expy (5.4L V8, 231K miles, 6R75 transmission) recently started throwing P0741 (Torque Converter Clutch Solenoid performance/stuck off) and intermittently P0735 (gear 5 incorrect ratio). The truck has been shifting flawlessly until recently, but now goes into limp mode after driving for a bit - wrench light comes on, RPMs run high, and shifts are very sluggish. (I have read the available threads on this already: This one, and this one, and this one, and this one....but none of them get me what I need.

The Problem: I'm having trouble nailing down the exact part number for the TCC solenoid. From what I've read, it's accessible once the pan is off, but I'm getting conflicting information. Here's where it gets frustrating: I called both my local Ford dealer and Fischer Auto Parts, and they both told me the TCC solenoid only comes attached to the entire valve body assembly - which is clearly not ideal (or cheap!). But I've seen posts where people have replaced just the solenoid itself.

I've found lots of part numbers online, but I'm not confident which (if any) is the correct standalone TCC solenoid. I don't want to order the wrong part and end up with something I can't use. I think what I need is this, but I haven't taken mine out yet to confirm it has a brown cap or not: https://cobratransmission.com/6r60-...ord-lincoln-mercury-vehicles/?showHidden=true

My Plan: Since I have to drop the pan anyway to access the TCC solenoid, I'm planning to do a complete service while I'm down there:

• Replace TCC solenoid
• Change transmission fluid (already have a drain plug, and I'm a few thousand miles overdue anyway)
• New filter
• New pan gasket

Questions:

1. Can anyone confirm the TCC solenoid is available separately for the 2007 Expy, and if so, what's the correct part number?
2. Has anyone successfully replaced just the solenoid without replacing the entire valve body?
3. Is the TCC solenoid the likely culprit for these codes, or should I be looking at something else?
4. Any tips for the job? Special tools needed?
5. Anything else I should inspect/replace while the pan is off?

I'm fairly handy with tools and comfortable doing this myself. Just want to make sure I have the right parts before I dive in. I'll document the process and post updates as I go.

Thanks in advance for any help!

Skip

 

[whySKIPdodis]

UPDATE: TCC Solenoid Access & Next Steps

Quick update on my P0741/P0735 situation for anyone following along or dealing with similar issues.

What I've learned: After doing more research and dropping the pan, I found out that the TCC solenoid is NOT accessible just by dropping the pan like I originally thought. You have to drop the entire valve body to get to it - which is a much bigger job than I'm comfortable tackling in my driveway.

What I've done: I went ahead and did a drain and fill with fresh Motorcraft SP fluid. Unfortunately, there's been no change to the transmission performance. Still getting the same codes (P0741 and intermittent P0735/0731) and still going into limp mode.

Where I'm at now: Given that the TCC solenoid requires valve body removal, and considering I'm at 230K+ miles, I'm now looking at either a rebuild or a remanufactured transmission. Even if it's just the TCC solenoid that's bad or the TCC itself, it doesn't seem worth throwing money at a high-mileage transmission that could have other issues waiting to surface.

I'm leaning toward a reman unit - seems like the smarter long-term investment with a warranty versus rebuilding what I've got.

Questions for the group:

1. Anyone have experience with reman transmissions for the 6R75? Any suppliers you'd recommend or avoid?
2. Should I be looking for one with updated components (I've read about CDF drum updates)?
3. Ballpark cost I should expect for a reman 6R75 plus installation?
4. Any other options I should consider before pulling the trigger?

I'll keep this thread updated as I move forward. Thanks again to everyone who helped troubleshoot!