Check the Chassis

author image

September 14, 2009

It’s a fact of RVing life: Things wear out and break on your rig, and require maintenance and replacement. When it’s something you can see, it’s no problem—it’s what you can’t see that can fail and cause a potentially dangerous situation.
We’ve been reminded of this numerous times in the past, but the most recent example is the rear control arms on some Monaco motorhome chassis, which have a tendency to crack or even fail completely. The chassis in question is the Roadmaster RR4R with the four-airbag “Monaco Gold” suspension. I’m not about to speculate on the cause of the problem, and I’m not going to suggest that the part was improperly engineered, but the fact is, the problem exists. We’ve seen it in our shop several times over the last couple of years.
If you own one of these coaches, there is good news. Source Manufacturing, LLC offers heavy-duty rear control arms for these coaches under part number TRA-1002. These arms are a direct replacement for the factory components, and include upgraded axle mounting hardware. Even if you have already had these parts replaced under warranty, Source warns that the replacements are the same design as the original, and therefore are susceptible to the same problems.
The TRA-1002 control arms are designed for Monaco Knight (’02-’04), Monaco Cayman (’02-’09), Holiday Rambler Ambassador (’02-’04), Holiday Rambler Neptune (’02-’09), Safari Cheetah (’02-’04) and Safari Simba RD (all years). We have these control arms in stock at Henderson’s Line-Up and can install them for you. We also carry upgraded control arm bushings for ’98-2000 eight-airbag chassis, which improve steering feel and accuracy.
Problems like this underscore the need for regular chassis check-ups. At Henderson’s Line-Up, we can perform a Road Performance Assessment (RPA) that ensures your coach rides and handles as it should, and includes a detailed inspection of the chassis. Quite apart from suspension maladies, we’ve found things like propane tanks that were ready to fall out, components coming loose, cracked brake rotors and cracked wheels. Having your coach inspected at least once a year (more if you drive it often or full-time) is cheap insurance against getting stuck on the road somewhere, or worse yet, having an accident. If you can’t get to our shop for an RPA, we have a list of RPA-certified shops that can perform one for you—but failing that, just get your coach inspected. It’s not what you can see that’ll hurt you—it’s what you can’t.

Leave a Reply


  1. brett heenan Sr.

    ins’t this the old Magnum chassis renamed under Roadmaster?

  2. Paul

    You only mention yr models 02–40 for the Cheetah. I have an 06 on the RR4R with the upgraded “Deluxe Suspension”. Do I have to worry about my coach? I’m in Flagstaff – Is Phoenix my closest RPA?
    Thanks, Paul

  3. Bernie

    Thanks for the well written and concise info. Perhaps add Roadmaster to your tag words so it will be easier to find for those with the Roadmaster Chassis.

    Either way, awesome info!


  4. Ray Scroggins

    As I won’t get to your shop anytime soon. please furnish names of RPA-Certified shops in New Mexico–Southern NM would be best. Thanks