You shouldn't tow with you vehcile for the first 500 miles when it's new and not get over 50 miles an hour.You have 18 k on the clock and I wouldn't worry about a thing. I would go get it come back and then get things changed out if it bothers you. Keep an eye on the Temp guage and let the big dog eat. If it starts to overheat just drop down a gear and let the rpms go up . This will cool things off for you. This truck is a towing beast and likes rpms, so dont be scared to drop down a gear and let the big dog eat.:cheers: