Looking for help for a family member that doesn't have internet access. They have a 2003 Landau "Georgie Boy", 35' with 8.1/Allison and Workhorse chassis. The problem: The unit is leaking differential oil to the point of having to add 3l after driving about 250km. They tow a Suzuki Vitara. The unit was taken to the Workhorse warranty center and was diagnosed with having a plugged vent tube. After close to two weeks, the vent tube was replaced and the owner sent on their way. They stopped after about 150 km to find their tow car covered in oil. The unit is now back at the warranty center. Given the unit has 10,000 km we are quite concerned about the cause and remedy of this problem. Their plan is to leave Canada for Mexico for their annual vacation. Has anyone else experienced this or a similar problem?