Suspension Q & A
January 1, 2002
Filed under Trailer How To
Q I’m the owner of an Itasca Spirit 23-foot motorhome with an 11,800-pound gvwr. Are there any modifications I can make to the suspension to eliminate the side-to-side motion due to wind gusts created when semi trucks pass by, or when the crosswinds are above about 15 mph? I’m also towing a small Mazda pickup, if that has any bearing on the parts I need.
— D.B., Greeley, Colorado
A First of all, do the cheap and easy “fix,” and check to make sure your tires are fully inflated to the recommended air pressure. If the tires are low, they’ll be extra soft and squishy, and that can aggravate a feeling of coach instability.
There are a couple of relatively easy components you can install to help stabilize your rig. These items include anti-sway bars, which are actually anti-roll bars, and air bags. Your coach may already have a factory-stock sway bar up front, but I’d suggest a pair of replacement heavy-duty front and rear bars. These bars resist body roll relative to the suspension, and can help avoid that uneasy-feeling, side-to-side action you’re getting in heavy traffic or windy conditions.
Contact Addco Industries Inc., (800) 338-7015, www.addcoindustries.com; Hellwig Products Company Inc., (800) 367-5480; or ipd, (800) 444-6486, www.ipdusa.com; to find the aftermarket bars you need.
I’d also recommend use of aftermarket air bags on your rear axle. These bags can be inflated to whatever pressure is comfortable for you (in such a manner that they don’t affect ride quality while still providing some extra support out back). While air bags are primarily designed to provide extra support for a sagging suspension, they also help resist body roll to some degree, which helps the stability situation. And by helping support the rig’s aft end, they help reduce the aggravated body roll that can be worsened by rear springs that are heavily loaded. Check out Air Lift Company, (800) 248-0892, or The Goodyear Tire & Rubber Company at (800) 541-7821.
As another suggestion, it never hurts to make sure your shock absorbers are in good condition. If yours need to be replaced, you can’t go wrong by installing Bilstein gas-charged shocks. These are top-notch aftermarket products that can help stabilize and control almost any motor vehicle. Contact Bilstein at Bilstein Corporation of America, (800) 537-1085.