We pull a 4500lb trailer behind our Sprinter based Navion. We call it the Wrangler JKU. Just keep the towed weight under the 5000lb drawbar capacity, the van weight under the 11030lb GVWR, and the total weight of van and towed together under the 15250lb GCWR, and you're good to go.
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 Wrangler JKU (sold @ ????) - 2016 Sunstar 26HE (sold @ 4600 miles) - 2002 Roadtrek C190P (sold @ 315,000kms)