SD Park Brake
The parking brake is mounted to the transmission extension housing and incorporates a case assembly and a cable actuated 9x3-inch Bendix brake. The case assembly consists of opposed mounted roller bearings, companion flange and mainshaft assembly installed in a one-piece aluminum housing. On F-Super Duty Motorhome vehicles only, the speedometer and speedometer cable assembly are driven by the speedometer drive gear, splined to the mainshaft. The case assembly has its own lubrication supply, separate from the transmission.
This makes it look like 2WD SuperDutys & Motor Homes use 4WD transmissions
'90-04 Driveshaft Brake Assembly F81Z2598BA 
![parkingbrakesd.jpg SD Park Brake
The parking brake is mounted to the transmission extension housing and incorporates a case assembly and a cable actuated 9x3-inch Bendix brake. The case assembly consists of opposed mounted roller bearings, companion flange and mainshaft assembly installed in a one-piece aluminum housing. On F-Super Duty Motorhome vehicles only, the speedometer and speedometer cable assembly are driven by the speedometer drive gear, splined to the mainshaft. The case assembly has its own lubrication supply, separate from the transmission.
This makes it look like 2WD SuperDutys & Motor Homes use 4WD transmissions
[url=https://www.amazon.com/dp/B0CKVCDJ6Y]'90-04 Driveshaft Brake Assembly F81Z2598BA[/url]](https://www.supermotors.net/getfile/283541/fullsize/parkingbrakesd.jpg)