Just got the car back after a trans rebuild and it whines like crazy in 1st and 2nd gear. Sounds like a police car! Noise stops in 3rd gear. Anybody have any thoughts about root cause on this? I am thinking maybe defective torque converter or a bearing either on the main shaft or secondary shaft. Other than the noise it runs fine - but the noise is intolerable. Thanks in advance.

 

Hello,

You interrupt that direct connection when you depress the clutch to change gears, then reestablish it when you let the clutch back out. In an automatic, there is a fluid coupling that dampens the interchange when the automatic changes between gears. The fluid coupling is called a torque converter in cars, and a viscous fluid coupling in other applications. In the late 80s, technology introduced the ability to "lock" the torque converter so that there was a complete mechanical connection between the engine and the drive axle (just like an engaged clutch) hence the term, "lock up" torque converter. In most cases, there is no electronic "check" for a torque converter. For the most part it is a pass/fail...it either works or it sits there and spins and nothing happens. There is an electronic check for the "lock up" function of a torque converter...because frankly most people would never friggin' know it wasn't working. If you threw a code, it was quite likely for the latter.

Regards
Anthony

 

Did they change any hard parts during rebuild ? That could throw the unit endplay off spec, or changing the pattern of the gears contact point, if so it will wear in as you put more miles into it. But you should bring it back to the shop and have them listen it the noise and see what they will do for you.