Problems have been reported with the 2009 and up Subaru CVT torque converter clutch not releasing. Engine may stall or drop engine RPM when slowing to a stop.
There have been many complaints on this symptom. Chatter within the industry tells us of valve body and torque converter problems. Our experience on this unit shows a large failure in the torque converter. The turbine hub is wearing out prematurely where it contacts the plastic washer on the front cover. The torque converter industry has seen this problem on several units over the years; most recently with the CD4E.
The factory has claimed to have updated this torque converter for this problem. It has been said that the update contains a thrust bearing on the front cover or turbine hub. We have not seen any of these current updates.
The clutch release clearance on the units that are not worn indicate less than .015″ of clutch release clearance.
We are currently machining the original turbine hub, and have used several different bearings in the past two years on the turbine. We have recently decided to stick with the 604 Chrysler transaxle bearing, for the convenience of availability (figure 1).
After machining, you can see where the finished bearing will pocket into the turbine hub (figure 2). The bearing is positioned above the face of the original contact point at .020″ as shown. This leaves .030″ – .040″ of clutch release clearance before weld (figure 3). We have had great success with this clearance for this particular unit.
Getting to Know the AS66RC
Introduced in the 2014 model year, the AS66RC was an option in the Ram Chassis Cab 3500, and standard equipment in the 4500 and 5500 models with a 6.4L Gas Engine. The AS66RC is basically the same converter as the AS68RC found in Isuzu applications shown in Figure 1, but with a different cover design.
Similar to its counterparts shown in Figures 2 & 3, the AS66RC is smaller in diameter than the AS68RC and the AS69RC found in the diesel applications. Upon internal inspection, you will find that the AS66 & 68 use the same bearings, seals, and 3 friction clutch pack design.