Still have P0741 after replacing TCC solenoid

Hi all, been a while since I've been around, (put a mustang motor in my 98 explorer, rebuilt rear end etc. with a lot of help from this site). Now I have an issue with the 5r55e (code D) transmission.

The o/d off light started flashing and it clunked as it went below 20mph while slowing down. The flashing comes and goes, and the tranny works fine when light is off. When light starts flashing, it does the clunk when I stop. Other than that, it shifts smooth and strong.

I took a chance and replaced the TCC solenoid, but the symptoms are back.
Brought it to the shop and they read the P0741. Cleared it, but it came back (intermittent).

Any ideas to trouble shoot before changing more parts or getting the tranny pulled?

Thanks
RYDREW55

 

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I would say at the very least you will need to replace the valve body & torque converter.

 

I'll have to clear the code and try, but it did seem to wait a bit before coming back last time.

Not sure what I would have seen to indicate a blown VB seal, but everything looked real clean down there. Wouldn't you need to remove the VB to see the seal (gasket)?

My understanding (but I by no means know from experience) is that the clutch locks up at speed to help with gas mileage, and then releases when you slow down. The clunk happens when I am almost come to a stop, slowing down to around 20 mph.

 

More info after test drive

Brought it to the shop and they read the P0741. Cleared it, but it came back (intermittent). Works fine when light is off. When light flashing, it clunks as it goes below 20mph when slowing down.

Adding some more info

Took it on a test drive to see if I could determine if the TC was locking up as it is supposed to at highway speed.

1. Light was on when I left my house. Clunking when stopping as it slowed below 20mph.

2. Light went off after 4 full stops (about 1.5 miles) before I got to the highway. No clunking on stops

3. Got on highway light still off. Got up to speed. No issue for 2 miles. Held speed, hit the gas. Revs went up about 500 rpms when I hit the gas (from 2,500 to 3,000). Not sure how much it should increase revs with TC locked, but did not seem excessive.

4. Light came back on on the highway. Hit gas at speed, seemed like maybe the revs were a little more when hitting gas. Maybe 700 or 800 (2,500 to about 3,300).

5. Light stayed on till I got home. Checked fluid OK. Restarted, light still on.

6. OD off on on works fine, even when the light is flashing it will go into and out of od.

Any other thoughts? It really runs and shifts fine, both with the light flashing and with light out. Just that damn clunk when I stop.

Thanks,
RYDREW55

 

Is it plausible that the clunk is from the ramped up pressure command of the "limp home" mode? Also, the easiest way to tell if you have lockup is to get up to cruising speed, and make note of the engine RPMs i.e. "normally at 55mph I would see around 2000rpm, but when the TCIL is flashing I'm at 2500rpm..."

 

It sounds as though the stator support bushing may have failed. IIRC that requires a new TC

 

Thanks. Is it something that can be tested to see? is it part of a new rebuilt bb or separate component that can be changed?
New TC means tranny out.

 

A lot of possible causes of P0741: valve body wear, other internal leakage, bad pump stator seal, piston hub wear inside the torque converter, and thermal bypass issues to name a few.