Newmar Motorhome Rough Ride Fix: Suspension & Air Pressure

The Rundown

Your 2013 Newmar on a Freightliner chassis should absolutely ride better than your previous Super C, so you're not expecting too much. The fact that you've replaced all six airbags but haven't adjusted the ride height is likely the main culprit behind your rough ride. Without proper ride height adjustment, even new airbags can't provide the smooth ride your Newmar was designed to deliver. Your chassis uses an air suspension system that needs to be properly calibrated to work effectively - it's not just about having good airbags, but having them at the correct pressure and height.

The Freightliner chassis under your Newmar should provide excellent ride quality when properly adjusted. Since you're feeling every crack and hole in the road, this indicates your air suspension is either under-inflated, over-inflated, or the ride height sensors aren't properly calibrated. This is a common issue after airbag replacement when the system isn't properly reset and adjusted.

Why It Happens

When airbags are replaced on your Freightliner chassis, the air suspension system loses its calibration settings. The Electronic Control Unit (ECU) that manages your air suspension needs to relearn the proper ride height and pressure settings for your specific coach. Without this calibration, the system doesn't know where the "sweet spot" is for optimal ride quality.

Your 2013 Newmar likely has the Freightliner ECAS (Electronic Controlled Air Suspension) system, which uses height sensors at each corner to maintain proper ride height. When new airbags are installed, these sensors need to be recalibrated to match the new components. If the ride height is too low, you'll feel every bump harshly. If it's too high, the suspension becomes overly stiff and transfers road impacts directly to the coach.

Additionally, the air pressure in each bag needs to be precisely set based on your coach's weight distribution. Your Newmar has different weights on each corner due to slides, tanks, and equipment placement. Generic air pressures won't provide the smooth ride you're expecting - each position needs individual adjustment.

Gather These Items

• Digital tire pressure gauge capable of reading 20-120 PSI accurately
• Air compressor with regulator (or access to truck stop air)
• ECAS diagnostic software (DDDL) or dealer diagnostic tool
• Multimeter for testing height sensors (if needed)
• Basic hand tools for height sensor adjustments
• Your coach's weight distribution report (or portable scales to weigh each corner)
• Freightliner chassis manual with air suspension specifications
• Notebook to record pressure settings and ride height measurements

The Fix

WARNING: Use proper torque specifications when adjusting height sensors or valves. Incorrect torque can damage components and lead to system failure. Always torque to manufacturer specifications.

Start by having your 2013 Newmar weighed at a truck scale or with portable scales to determine the actual weight on each corner. This is critical because your air pressures need to match your specific weight distribution. Verify correct pressure ranges with your dealer or chassis manual, as these numbers must be adjusted based on your actual weights.

The most important step is getting the ride height properly calibrated. Your Freightliner chassis has specific ride height measurements that must be met - verify the correct specifications for your model with dealer or manufacturer documentation. Use the ECAS system's electronic height adjustment through the control module to set the correct ride height while the coach is loaded to travel weight. The height sensors need to be in their neutral position when the coach is at proper ride height.

If you have access to Freightliner ECAS diagnostic software, connect it to perform an automatic ride height calibration. This will reset the ECU and establish new baseline settings for your replaced airbags. Without this software, you'll need to manually adjust each corner using the height control valves while monitoring the ride height carefully.

Test drive after each adjustment, starting with moderate air pressures and proper ride height. Fine-tune the pressures based on ride quality - if it's too harsh, reduce pressure by 2-3 PSI increments. If it feels bouncy or unstable, increase pressure gradually. Document all settings so you can return to known good configurations.

Know Your Limits

While you can handle basic pressure adjustments and height measurements yourself, the electronic calibration of your Freightliner air suspension system really requires professional diagnostic equipment. If you don't have access to ServiceLink software, plan to visit a Freightliner dealer or qualified heavy-duty truck shop for the initial system calibration after your airbag replacement.

Don't attempt to modify or bypass any height sensors or electronic components - these systems are precisely engineered for safety and ride quality. If height sensors are giving incorrect readings, they need professional diagnosis and possible replacement. Incorrect calibration can lead to dangerous handling characteristics or premature component failure.

Keep in mind that even with perfect suspension setup, your Newmar won't ride like a luxury car due to its size and weight. However, it should definitely provide a much smoother ride than your previous Super C. If proper calibration and pressure adjustment don't resolve the harsh ride, you may have issues with shock absorbers, suspension bushings, or other chassis components that will need professional inspection.