Many torque converter builders know that a perfectly-built converter can be ruined if related parts in the transmission do not operate as they should. It is never fun to face a comeback…and it is even worse when the comeback was not related to the quality of your build.
GM 6L50/80/90 OE units are built with a PTFE-impregnated pump bushing. When this bushing wears out or is damaged by a converter failure, transmission rebuilders often struggle to find replacements as they are unavailable from GM. They can either buy an entire bell housing to get the OE bushing, or settle for aftermarket bushings that don't offer the durability they need.
When these aftermarket bushings fail, they delaminate before they seize, spreading contamination throughout the system (Figures 1 & 2). Some builders may — incorrectly — come to the conclusion that the new converter is somehow to blame.
Fortunately, transmission rebuilders now have a solution they can count on: Sonnax direct-replacement pump bushing 104034A. This OE-style bushing is impregnated with highly wear-resistant PTFE — not simply adhesive coated — providing unmatched durability, precision fit and optimal function.
Every time you sell a converter for GM 6L-series transmissions, always recommend that your customers install the Sonnax bushing to ensure that your converter has the best support available.
Not for use in 6L45 BMW models, which have a bearing in that position.
While Sonnax makes every effort to ensure the accuracy of technical articles at time of publication, we assume no liability for inaccuracies or for information which may become outdated or obsolete over time.