Torque converter noise

[Doctor J]

If you hear the noise (high pitch whine) that is present only after you shifted out of park or neutral while the drive wheels are stationary it most likely to come from the torque converter. However on the old car this noise may be masked by exhaust rattle, belt squeaks or even sheet metal vibration. This method works on A140e transaxle with electronic control (Not A140L). This test is need to be made only if there is a strong suspicion that noise originates from the torque converter and is not recommended to be used as pre-purchasing inspection of the car. The test is performed as follows:
1. Unplug the connector to the solenoids (to put transmission in MANUAL mode)
2. Modify remote starter switch so it could reach from the battery to the steering wheel
3. Attach one clip to the lock up solenoid terminal (number 3 solenoid or SL solenoid)
4. Connect other clip to the battery positive terminal
5. While sitting on the driver seat
· Start the engine
· Apply the brakes
· Shift to 2 (this will put transmission to the 3rd gear)
· Push the button of the switch. This will apply TC clutch, blocking the converter. The engine will bog down and may die, so hold the button just momentary to hear if noise is going away. (On the car I tested the noise disappeared right away, and rpm fell from 800 to 400, but the engine did not died)

This test will not work at the first gear, because the Lock-Up signal valve hydraulic circuit is blocked by 1-2 shift valve. (Fail safe feature).

Now, there is a bunch of questions:
On the car I tested (88 Camry Wagon 128 kmi), the original TC was replaced with the rebuild one to cure the noise complaint AND the unsatisfactory low stall speed (1400 rpm vs. 2200). The replacement did not make improvements. There were no broken metal chips in the pan and fluid was bright red after 20000 mi. of service. The transmission shifts fine, however the car starts to move from the stand still like “overloaded”. The noise briefly intensifies (screams) then goes away. The transmission input and stator shafts are in the good condition (radial and axial play within the specs) The removedTC had no contamination either!
Based on the diagnostic article by L.Carley, the whining noise is pointing to the TC roller thrust bearings.
I am personally suspecting several reasons for the noise:

• The TC lock up clutch is not fully releasing (however It applies at 50 mph as confirmed by test light on the solenoid and RPM drop on the tach).
• The engine (3SFE) thrust bearing is badly worn, transferring the thrust load to the TC bearings (but the drained engine oil was clean)
• The rebuild TC is bad
• There is misalignment between engine and transmission.
• Defects in lock-up relay valve (allows bleeding of lock up pressure, that allows TC clutch to drag )

Have anybody had the same or similar situation?
The used transmission is the last resort solution due to the poor quality of used units.
Note: I will post this thread in several forums to get most responses. NO JOKES PLEASE!!!

[toyomoho]

Not an auto trans wizard. Take it the TC replacement included both the torque converter and stator clutches. Does the noise and sluggish acceleration occur in both 1st and R gears? Once the car is moving is the acceleration OK in 2, 3, etc? The noise is coming from the trans and not the exhaust system?

[Doctor J]

Thanks for repply.
The noise disappeared after I locked the TC using the test I described above.Yes, the car has sluggish acceleration from stand still or uphill accompanied by noise that sounds almost like a supercharger. Once torque load is reduced the noise diappears.
The car's owner (my uncle) first noticed poor pick up from stand still (as the car was really fast off the line and then paid attention to the noise.