Best Anti Sway Bars for 2021 Tiffin Phaeton 37BH Freightliner XC Chassis  

Question:

Expert Reply:

Hi Mark, welcome back!

Based on your 2021 Tiffin Phaeton 37BH on a Freightliner chassis and not the PowerGlide, the most common chassis is the Freightliner XC chassis, and for that setup the confirmed anti sway bars are the Roadmaster rear bar part # RM-1209-140 and the front bar part # RM-1209-139.

Most people start with the rear because that’s where you feel the biggest improvement in stability, especially with crosswinds and passing trucks, and then add the front later to really tighten up steering control and reduce body roll. These heavier duty sway bars replace the factory bars with thicker ones that do a much better job controlling side to side movement, which is what helps take that white knuckle feeling out of driving a larger coach like your Phaeton. The result is a more planted feel on the road, less push from semis, and better overall control without constantly correcting the wheel.

With that being said, I do want to be upfront that this recommendation is based on the most common XC configuration and these bars will not fit the XCR version, so to be completely certain before ordering we would want to confirm your exact Freightliner chassis model or VIN. I know the last thing you want is to get everything lined up and run into fitment issues, so I’m happy to double check that with you if you have that info handy.

Where do you most want to feel that improvement, more on long interstate drives, mountain passes, or dealing with coastal winds?

expert reply by: Heather A

0

Mark B.

4/30/2026

Thank you for your attention. My VIN is 4UZACGFE9MCMT3291. I look forward to your confirmation as to which XC model chassis I have and which sway bars I need. I would also be interested to know the best Koni shocks available for front and rear.