I AM A MACHINIST IN A REPAIR SHOP. THIS IS A MOTORHOME. SITS ON A DYNOMAX FRAME WITH A 625 HP ENGINE AND WEIGHS 47,000 LBS. CUSTOMER EXPERIENCED R/H DRIVE AXLE BEAM ASSEMBLY BETWEEN REAR AXLE AND AIR SUSPENSION BAGS TO BODY BUST IN HALF, ALSO THREW THE DRIVELINE. HE WAS ENTERING A FREEWAY AT UNDER 20 MPH WHEN THIS OCCURRED. THE IMMEDIATE EXTREME LEAN TO THE DRIVERS SIDE HAD THEM SUSPECT THE DRIVESHAFT TOOK OUT AN AIRBAG. INITIALLY BROUGHT TO ANOTHER SHOP TO REPLACE THE DRIVELINE WHEN THE REAL CULPRIT WAS DISCOVERED. BROUGHT TO OUR SHOP FOR MAJOR REPAIR. I EXTRACTED THE BROKEN LOWER BEAM ASSEMBLY, THE NEW PART HAD TO BE MADE WITH A 4 WEEK LEAD TIME. DURING THIS STAGE I DISCOVERED THE OTHER SIDE WAS NEARLY READY TO BREAK AS WELL. I HAVE DOCUMENTED THE REPAIR, AND UPGRADES PERFORMED TO THIS CONDITION AND HAVE SEVERAL MORE PHOTOS AND TECHNICAL UNDERSTANDING ON THIS THAN WHAT IS INCLUDED IN THIS INITIAL COMPLAINT. THESE ARE AVAILABLE UPON REQUEST. FACT IS, THIS IS A SERIOUS UNDER DESIGN THAT COULD BE CATASTROPHIC IF THIS OCCURS AT HIWAY SPEED FOR MORE THAN JUST THE OCCUPANTS. SIMPLY REPLACING THE BROKEN PART WAS NOT A REASONABLE SOLUTION ESPECIALLY AFTER FINDING THE OTHER SIDE DOING THE SAME THING. THE OTHER SIDE WAS REPAIRED, AND ADDED REINFORCEMENTS WERE INSTALLED TO BOTH THE REPAIRED SIDE AND THE NEW BEAM SIDE. THIS MOTORHOME HAS APPROXIMATELY 76,000 MILES ON IT AT 10 YEARS OLD. FAILURE IS DUE TO THE LOWER BEAM DESIGN CARRYING BOTH COACH WEIGHT AND ENGINE TORQUE THROUGH A SMALL AREA THAT FLEXES UNDER ENGINE TORQUE OVER THE TOP OF THE AXLE ONLY. THE REAR OF THE BEAM ATTACHES TO THE TORQUE BARS FROM THE CHASSIS, WHEN THE AXLE IS POWERED TO DRIVE THE WHEELS PUTS AND ENORMOUS AMOUNT OF TWIST INTO AN UNDERSIZED AREA ON THIS BEAM WITHOUT ADDITIONAL SUPPORT. ALL MOTORHOMES WITH THIS CONFIGURATION NEED INSPECTED AND POSSIBLY REINFORCED SIMILAR TO WHAT I DID HERE.
- NHTSA ID
- 11174582
- Incident
- Sep 10, 2018
- Mileage
- 5 mi