You might have a Schwintek slideout system. It'll have an upper and lower track, on each side.
If so, go to YouTube for troubleshooting videos on the Schwintek or to Lippert's website.
No manual crank with that system.
Dan-Retired California Firefighter/EMT
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package