Upgrading the Cummins Roller Clutch

When the Cummins diesel was offered in 1989 Dodge pickups, it could be purchased with either a manual transmission or a non-lockup 727 automatic transmission. The converter for the non-lockup 727 transmission was very similar to the 400 or AT540 converters, and had many internal likenesses. The converter’s historic durability made it a good choice for this demanding application, but this converter also has some historic shortcomings.

One weak point has always been the spring retainers. The spring retainers’ main job is to provide support to the springs that load the rollers of the roller clutch. This support not only regulates the amount of tension on the rollers, but also keeps the tension equal throughout the length of the roller. As the spring retainers wear, they move away from the rollers, lessening the tension on the rollers, and as the retainers weaken, they no longer stay parallel to the rollers. This allows the tension on the rollers to become uneven, causing the rollers to walk forward and come into contact with the stator cap.

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Article No.: TCTIP-02-06
Author: Mark Mustard
Total Pages: 2