1975 Avco Motorhome with a 5.9 L Cummins and Ford 4WD Drivetrain

Eric Bureau enjoys camping in Baja but the factory powertrain in his 1975 Avco Grand Lodge motorhome just couldn’t tackle the tough roads and sand.

The RV was originally built on a Dodge M600 chassis with a Dodge 440 ci V8 and 727 Torqueflite three-speed automatic transmission. Eric replaced those with a 5.9 L Cummins diesel inline-six mated to a Allison 2400 five-speed automatic transmission.

Power is sent to all six 315/70/22.5 tires through a Ford F-550 4WD drivetrain featuring a Dana Super 60 front axle and Dana S110 rear axle with a Posi LSD. The RV has a drivetrain improved fuel economy from 6 mpg to 11 mpg. The engine is fed from two 45 gallon fuel tanks. Eric improved braking thanks to an exhaust brake and Hydromax brake booster. The RV also features a compressor with 30 gallon air tank, a hydraulic leveling system, and 12,000 lb winch.

Inside the cabin you’ll find an on-demand water heater fed from two 75 gallon water tanks. There are also three AC units. The one up front is a 45,000 BTU model from a bus used while driving. The other two are 9000 BTU units mounted on the roof and are used while camping.