Apparently the PTU's were being killed by heat. I saw some pics and spoke to the Wash DC Fleet Manager who said they pulled them out and inside the oil was burned and had the consistency of lard.
I just had my work 13 Utility PTU replaced a few weeks ago, same thing killed by heat. Never saw the inside of mine though.
Yes couldn't drive it at all.
So much for that lifetime lube... Having the part be serviceable would have easily prevented failures like this. I am so worried about my PTU. Wish I could check the PTU oil.
EDIT: I actually found an article about the police interceptor PTU's and they seem to have a special police PTU. It's surprising that they have a large number of them failing. Now I'm worried about my 2011 and its civilian parts. Oddly enough, the police PTUs seem to actually have serviceability.
https://www.hendonpub.com/police_fl...d_nextgen_police_intercept_tech_trning_part_1
"Walk Around (and Under)
The classroom portion began with a quick overview of the 3.5L (base engine) V6 PI Sedan AWD, the 3.7L V6 PI Utility AWD and the 3.5L EcoBoost (twin turbo) V6 PI Sedan AWD. Then a walk around (and walk under) was conducted with the PI Sedan and PI Utility.
Both the PI Sedan and PI Utility operate as FWD vehicles until wheel slip is detected. Only then does power transfer to the rear wheels. Of the most importance, the transaxle with water-cooled (police-only) AWD Power Transfer Unit was located. And then the rear axle mounted Active Torque Coupling Unit attached to the Rear Differential Unit was pointed out. On these AWD vehicles, power is continually fed to both the front half-shafts and the rear driveshaft. The driveshaft is constantly engaged and rotating even if power is not fed to the rear wheels.
The Front Wheel Drive system and the Power Transfer Unit send torque back to the rear clutch pack all the time. Any time the vehicle is moving, the driveshaft to the rear is turning. The Active Torque Coupling mounted on the Rear Differential Unit only passes on torque when needed. But it is literally right there when it is needed.
The Powertrain Control Module sends a signal to partially or fully engage or disengage the Rear Wheel Drive part of the AWD. Based on input from the four wheel sensors feeding the ABS module, the steering-angle sensor module, and the instrument cluster module, the PCM sends a signal to the AWD really module and the 4x4 lock solenoid in the Active Torque Coupling. As this progressively locks up, power is sent to the Rear Differential Unit and on to the rear wheels.
The ATC, in turn, is controlled by the PCM. The amount of torque is infinitely variable, not just engaged-on and disengaged-off. It can deliver zero percent to the rear, like it does in the default FWD condition. Or it can deliver anywhere from 1 percent to 100 percent of the engine torque to the rear wheels.
Police-Only Power Transfer Unit
Since the Power Transfer Unit operates all the time to spin the driveshaft to the rear, the PTU can get hot. On the police version, a number of steps are taken to assure reliability and durability in police use. First, a cooler is added to the front of the PTU housing. The police-only PTU housing has an integral water jacket connected with water lines that run to the bottom three coils of the radiator. The jacket receives engine coolant from the radiator to maintain the correct PTU oil temperature.
Second, the PTU has a gear lube temperature sensor. A module keeps track of the gear lube temp, and how long / how often it was at that temperature. When a threshold is reached, a change PTU Oil light activated.
Finally, the AWD system has a two-stage way to protect itself from damage during extreme, prolonged use. The ATC as a heat protection strategy based on a number of factors, including wheel speed and duration of activity, to determine if overheating is occurring. If the ATC detects overheating, it will lock the clutches together to cool them. Clutches that slip to provide partial torque transfer get hot from the friction of the slippage. Locking the clutches stops the slip and cools the entire unit. In a locked condition, power is transferred to the rear wheels.
If the temp continues to rise even in a locked condition, the PCM disables the coupling altogether. The vehicle operates only as a FWD. AWD OFF is displayed. On the Police Interceptors, the PCM will automatically exit heat protection mode and clear the AWD OFF message when the temp returns to normal. This whole process is sped up by turning the ignition off and allowing the vehicle to cool for 10 minutes.
The ATC/RDU used on the Police Interceptors uses fluid-filled “wet” clutch packs. The retail Taurus and Explorer use dry clutches. The PI wet clutches can withstand higher temps and withstand higher temps longer than the retail unit. The ATC and RDU are not field serviceable. In case of a problem with either system, the whole unit is replaced."
