Our 5th also has 3 slides. The BR slide is a Schwintek (sp?) which is a completely different mechanism from the other 2. Most notable is that it has 2 motors that are sync'd by a fancy control module. It's easy to spot that type of mech by the gear tracks on each side of the slide. They've had mixed reviews since making an appearance but ours seems to work fine. The two motors make a kind of high pitched noise but it goes in/out pretty straight and smooth. If you have this type of hardware you can find several YouTube videos that discuss how they work, how to diagnose and how to sync the motors. Imnaha is right, the dealer needs to check it out.
2013 F-350 CC SB 2WD 6.7PS
2013 Eagle Premier 351 RLTS
-SOLD- 2012 X23B
-SOLD- 2003 Ford Expedition 5.4, Bilstein shocks