In rebuilding a 46-47-48RH/RE transmission the overdrive sun gear or associated bushings are often found to be damaged. The sun gear teeth are frequently pitted and spalled after extended normal operation. This damage can be the result of high stresses due to overloading, poor lubrication, or simply that the OE sun gear has completed its expected service life. If the damaged sun gear is reinstalled, the planetary gears will also become damaged and the entire planetary assembly will have to be replaced.
The Sonnax 15° helical cut overdrive sun gear comes with bushings installed for direct replacement onto the intermediate shaft and provides improved oil flow to and through the gear and bushings by increasing the width and depth of the grooves cut into the I.D. of the gear.
This part can be used to replace all OE 15° helical cut sun gears, regardless of pinion count. This part, like the OE, has a single ID groove between the spline and gear, and cannot be assembled with 22 1/2° helical cut gear components. Follow the factory manual instructions carefully. Removing and reinstalling the overdrive clutch spring can be hazardous.