245mm improvements

245mm improvements ImageImage While on the topic of the 245mm torque converter, we would like to share a few improvements that may reduce converter comebacks.

First, we must remove the stator outer race. You can either tap it upside down on the bench or simply lay it on one of your clutch bonder plate at 400 degrees. The race will drop out in just a couple of minutes.

After careful observation of the stator, check to see if it has the holes penetrated through the oil slots as shown (Photo A). If not, a .100 drill will do the job. Drill all four holes all the way through. This will increase lube oil to the roller clutch and reduce roller scuffing.

Second, look at the wear from the roller scuffing on the stator surface (Photo B & D). This can be machined away (.003 or .004 will usually do) with minimal material removal. This allows for smoother roller apply and release, preventing bind up from unequal apply pressure, that can cause stator shudder and/or complete failure.

When the rollers jam, even momentarily, performance decreases and heat increases. If the rollers cannot apply smoothly, a small amount of drivetrain vibration can occur on acceleration. It is often blamed on bad engine mounts or ignition misfire.

Our third improvement may solve many comebacks you may have experienced. After stator disassembly, machine .050 from surface “A” in Photo C. This surface causes interference with the pump impeller resulting in a bearing-like buzzing noise. GM has eliminated this part from the casting on many applications of this stator. No negative affects are caused by eliminating this.

Found in issue 09, 2004