Clutch Pedal/linkage problems of the 2005 Nissan Frontier

Took my truck to peltier in tyler for an ecm relay recall. Mechanic looked at truck and found that the radiator transmission cooler was leaking anti-freeze into my transmission. Was told to replace radiator immediately and flush transmission. Did this however transmission went into limp mode and progressively got worse. A mechanic replaced the valve body which cost over $1000 for the part alone and checked the clutch packs in the transmission. Clutch packs checked okay however the mechanic could not guarantee that the torque converter was okay. Vehicle seemed to drive okay after the repair. Now the torque converter seems to be going out and the vehicle will go into the limp mode. I have to disconnect the battery to reset the code and it will drive okay for about 10 miles and the service engine light goes on. When this happens the vehicle goes into the limp mode. My mechanic told me that he thinks the torque converter is shot and will have to be replaced. Update as of 07/192011 - mechanic replaced my torque converter and rebuilt transmission. The old torque converter came apart and after pulling the transmission, he saw a lot of metallic shavings on the screen on the valve body. While driving to work on 07/22/2011, I was driving around 70 mph with the cruise control on. All of a sudden my rpm gauge redlined and my transmission went into neutral. I immediately released the cruise control by tapping the brake pedal. With no shoulder on the road at my location, an 18 wheeler was quickly coming up on my rear. I put my flashers on and was able to coast to an exit. The 18 wheeler came within inches hitting my rear end. Now my Frontier is in dunn's transmission shop in tyler, TX to be repaired. As of this writing, the problem has not been diagnosed but I am sure the problem will be in the valve body since something caused the transmission to go into neutral. Probably some metallic material got inside something in the valve body which was replaced in March 2011.