ATSG frequently receive calls from rebuilders who find the reverse clutch spring retainer snap ring popped out of its groove with RE5R05A transmissions causing reverse clutch failure (figure 1). This is due to several reasons; the snap ring groove in the case is shallow, the snap ring is thin and the spring return is quite stout (figure 2).
FIGURES 1-3
The snap ring and retainer do not have much room to move too far forward with a good reverse clutch stack up. The snap ring will rub up against the reverse clutch cushion plate. The distance the spring retainer can move forward begins to compromise the apply of the clutch. Over time, should the reverse clutch stack up develop excessive clearance, the retainer could spin out of position causing a loss of reverse (figure 3).
FIGURES 4-6
One way to resolve this from re-occurring is to find a slightly larger snap ring that will allow the overlap of the snap ring ends (figures 4, 5 and 6). Place a mark on one end where it overlaps the opposite end. Then grind the tip down to the mark. When the snap ring is installed the ends will now butt up against each other. In this way, the greater the force working on the snap ring, the tighter in the groove it becomes as the ends are pushing in to each other.
If finding a snap ring large enough as well as thin enough becomes difficult to locate, you can purchase one from Superior Transmission Parts (Part No. K0108).
Subscribe to Motor Age and receive articles like this every month…absolutely free. Click here