Cause:
Lack of flange or stop surface on the case bushing.
Correction:
Sonnax no walk-out case bushings are flanged to prevent movement in either direction.
The OE case bushing in vehicles with a GM THM-400, 4L80-E and 4L85-E transmissions tends to walk out of the housing bore. This leaves the output shaft unsupported, ruins the governor gear and can cause case damage. The no-walk flange feature of the Sonnax case bushing 34006-SP is specially designed to keep the bushing in the case bore.
High-quality bronze
Flange on the transmission case side prevents bushing from walking completely through the bore
Flange accurately locates and helps retain the selective washer
Machined oil grooves allow for a supply of lubricating oil to enter the extension housing as well as the transmission case.
Note:
The housing bore should measure between 2.1285"/2.1295" in diameter for an ideal fit. When damage to the case is so severe that bore diameter is larger than 2.129", use Sonnax oversized case bushing. See instructions for details.
No walk out type bush
Symptoms:
Cause:
Lack of flange or stop surface on the case bushing.
Correction:
Sonnax no walk-out case bushings are flanged to prevent movement in either direction.
The OE case bushing in vehicles with a GM THM-400, 4L80-E and 4L85-E transmissions tends to walk out of the housing bore. This leaves the output shaft unsupported, ruins the governor gear and can cause case damage. The no-walk flange feature of the Sonnax case bushing 34006-SP is specially designed to keep the bushing in the case bore.
Note:
The housing bore should measure between 2.1285"/2.1295" in diameter for an ideal fit. When damage to the case is so severe that bore diameter is larger than 2.129", use Sonnax oversized case bushing. See instructions for details.
Specifications:
SONNAX Installation Instructions