Our customer arrived at our door with a beautiful, black Mustang shaking and rattling at idle and running poorly on acceleration. My test drive revealed that the car ran smooth with no codes and no noises until it warmed. I also heard and felt a probable throw-out bearing issue, as the sound changed with clutch pedal pressure.
A 2000 Mercury Grand Marquis with a 4.6L engine using a 4R70W transmission is at a general-repair shop for weeks. The problem is an intermittent engine surge on top of the 1-2 shift when hot. The perception is an engine problem. Eventually, the idea of the converter clutch coming on was being considered. Without much testing, the valve body and solenoids were replaced yet the problem persisted.
Our technical help line is now experiencing a different transmission that can have a variety of severe shifts complaints. It is with Ford’s 6R60/80 transmission. We received one such call from Mr. Transmission in Louisville, Ky., with a 2007 Explorer Sport 4.6L that had 65,000 miles. It shifted fine until you went for passing gear out of 4th. The shift was so brutal that it felt like the transmission went into reverse. There were no codes present. An entirely different call was a complaint of firm shifts and during full throttle kickdowns the vehicle speed signal would drop to zero. It too did not have codes. Yet another call received, all the shifts were extremely severe and it had a variety of CAN BUS codes stored.