I changed my wardrobe slide gearbox. Mine was gear/chain setup. Very easy to R&R the gearbox but be sure to mark the chain, otherwise you will spend time adjusting it. Don't use chalk to mark the chain, the chalk will dissolve into the oil, use a piece of wire or zip tie instead. Check Youtube there are a few videos that may help.
2015 Rockwood 8289WS
2003 Dodge Cummins w/Banks 3:73