Another P0741 Code

[lmarkie74]

Rebuilt 5R55W 15,000 miles ago. Removed Valve Body, cleaned, completely tore apart, brushed, and install a shift kit. Kit said it should take care of the Torque Convertor slip. Car drives nice and smooth, but still getting the P0741 code. Thransmission is surging trying to lock the clutch up. Solenoid must be working because it is trying to lockup. Any sugesstions?

 

[imp]

Rebuilt 5R55W 15,000 miles ago. Removed Valve Body, cleaned, completely tore apart, brushed, and install a shift kit. Kit said it should take care of the Torque Convertor slip. Car drives nice and smooth, but still getting the P0741 code. Thransmission is surging trying to lock the clutch up. Solenoid must be working because it is trying to lockup. Any sugesstions?

@lmarkie74
Torque converters always "slip", that being an incorrect use of the word, but slip is used to describe the difference in speeds between the engine and converter output shaft. Slip is the churning of the fluid within. The clutch has the purpose of mechanically "locking" the engine to the converter output shaft, thereby bypassing the converter altogether and eliminating slip.

Your code is telling you the clutch itself is failing to lock up due to mechanical reasons rather than electrical. You have 2 choices available: disconnect the Torque Converter Clutch Solenoid connection, which will eliminate the "surging" and drive with the clutch permanently disengaged, and buy ~ 3 or 4 % more gasoline, or,

Yank out the transmission and converter, and replace the converter. Driving with a non-functioning TCC will not harm the transmission. We drove automatics that way for 50 years before they started using those infernal clutches. imp

 

[lmarkie74]

A rebuilt torque converter was installed when I rebuilt the transmission. 15,000 miles. Sad to hear.

 

[imp]

A rebuilt torque converter was installed when I rebuilt the transmission. 15,000 miles. Sad to hear.

@lmarkie74
Very sad. Any chance of warranty? These types of failures and repairs lend themselves to the unscrupulous shops: blame some other part for the failure, dodge the truthful explanation by blaming the part's supplier, the driving habits of the owner, or any of a bunch of other bullshit cop-outs. imp

 

[lmarkie74]

Here is what my valve body looked like before I installed a rebuild kit. The material in the passages reminded me of the copper stuff in that Bar's Stop Leak. Very fine particles.

I'm thinking that it is band material and the bands need to readjusted?

 

[imp]

Here is what my valve body looked like before I installed a rebuild kit. The material in the passages reminded me of the copper stuff in that Bar's Stop Leak. Very fine particles.

I'm thinking that it is band material and the bands need to readjusted?

@lmarkie74

There is always "bronzy" looking stuff deposited in trans. fluid. Usually you can see it in the drained fluid making it sort of shimmer as it's swirled around.

I've always suspected it comes from the clutch plates; there is far more surface area involved there than the bands. It can't hurt to readjust the bands, simple procedure. In fact, on my 5R55S, there are two different procedures listed for the O/D band: back off 2 turns for cars, 1-1/2 turns for trucks. I did the 1-1/2 and it eliminated slight slippage I was feeling in 5th. gear. How long? It's been over a year now.

BTW, specs are identical regarding rebuilding the W and S transmissions. imp