Published on March 7, 2017 - (Updated on October 15, 2026)
A motorhome can look spotless on the lot and still hide costly problems underneath. Fresh paint and a clean interior say little about the frame, suspension or engine.
Many buyers take a short test drive and never look closely at the parts that carry the coach down the road. That gap can lead to big repair bills that neither the buyer nor the seller saw coming.
This guide explains the main chassis areas a pre-purchase inspection covers and what each one can show.
Two terms come up early in most motorhome searches. The chassis is the structure and mechanical side of the coach.
The house is the living space, such as the kitchen, bathroom and lounge.
This guide focuses on the chassis. A companion article covers what to check inside a motorhome's living space.
Chassis repairs can be some of the most expensive a motorhome owner faces.
The chassis is made up of several groups. A thorough inspection works through each one in turn.
The frame is the backbone of the motorhome. It includes the frame rails, crossmembers, brackets and mounts that hold the coach together.
Rust and corrosion are the main concern on any frame. The underside faces weather and road conditions every day.
That is true whether the coach is on the road or parked.
A dry climate does not rule out frame rust. Over the years, road debris and sand can chip away the protective coating.
That leaves bare metal open to salt and moisture.
Some surface rust is common on bare steel. The findings that call for a closer look are rust that goes deeper than the surface, bent parts and unusual repairs.
Fresh undercoating or foam in just one spot can also raise questions. These materials can hide rust that was already there.
Welds tell their own story. A weld that does not match its partner on the other side of the frame often points to a past repair.
When a repair turns up, inspectors look at how complete it seems. A damaged section that was cut out, replaced and braced looks very different from a single weld line run across a problem spot.
Some of the most useful chassis checks are also the simplest. Cracked or dry bushings, bulging seals and fresh leaks can often be spotted with a flashlight and a careful look underneath.
Many motorhome chassis use air bags inside the coil springs. These bags are often overlooked.
A bag in good shape is fully inflated and shows no sign of pinching.
Rubber grommets along the suspension can wear out or go missing. Missing grommets are a common item to bring up with a seller before a sale closes.
Hydraulic leveling jacks are part of the check too. Wet spots around the jacks can point to a leak.
Brakes, steering and suspension all fall within the work of a qualified chassis mechanic. These systems affect how the coach handles and stops.
Their condition carries real weight in a buying decision.
Tire condition is about more than tread depth. The DOT date code on the sidewall shows the week and year the tire was made.
RV tires often age out before the tread wears down.
Cracks and bulges in the sidewall are warning signs. The spare tire is part of the picture too.
The tires on the coach also need to meet the ratings the coach requires.
A certification label on the motorhome lists its weight ratings. Comparing that label with the tires on the coach helps show whether the tires are a proper match.
The mechanical side of a motorhome can run up large repair bills in a short time. A careful inspection goes well beyond hearing the engine start.
Inspectors look for leaks and for seals or gaskets that bulge. When they find wet spots around the engine, transmission or differential, they try to trace them to the source.
The exhaust system matters too. Rust that eats through the pipe near the turbo can affect performance and safety.
Broken or missing exhaust hangers are another common finding.
Loose wiring harnesses can hang low enough to catch on the road and tear. Low-hanging plumbing lines under the coach face the same risk.
The back end of a motorhome can take damage from steep driveways and gas station entrances. The generator and fuel tank area near the back faces that same kind of contact.
Service records help fill in the rest of the picture. Records of fluid changes, belt replacements and other routine care show how the coach has been kept up over time.
The body and roof do more than shape how the coach looks. They keep water out of the walls and floors.
Delamination is one of the bigger concerns in this area. It happens when moisture gets inside the outer wall.
The water breaks down the glue that holds the outside panel to the wood behind it.
Where delamination shows up, leaking sealant on the roof or around windows is often found nearby. Delamination repairs can be extensive.
A sound roof is solid around its edges, seams and rooftop fixtures. Sealant that is dry, cracked or pulling away from a seam is due for resealing.
Sealant itself is a normal upkeep item. Signs of an ongoing leak or soft structure underneath are the bigger worry.
A road test is still a valuable part of the process. It can show pulling, shaking, wandering, slow shifts and warning lights.
Clunks, squeals and loose steering can show up at low speed. Soft or uneven brakes, smoke when speeding up and signs of overheating are other things a drive can bring out.
Some problems only appear once the engine is fully warmed up. A quick loop around the lot may not tell much.
A second look underneath after a longer drive can show fresh leaks that were not there before.
Even so, a test drive misses a lot. Much of the condition of the driveline, suspension and electrical system cannot be judged from the driver's seat.
Most people would not buy a stick-built home without a home inspection. A motorhome is a house on wheels, and the same thinking applies.
A professional inspection is especially useful on complex diesel chassis. It also helps on coaches with thin maintenance records.
It works alongside a buyer's own walkthrough rather than replacing it.
Test Drive Technologies has inspected vehicles since 2009.
CEO Steven Paul has more than 25 years of hands-on work with cars, trucks and heavy equipment. That includes six years as a U.S. Army mechanic.
He holds ASE and NRVIA credentials. He has personally performed more than 8,000 vehicle inspections.
Not always. A motorhome that sits for long stretches can have low miles and deep tread on tires that are still old.
The DOT date code says more about tire age than the odometer does.
Records give a clearer picture of how a coach was cared for. This matters most on older or higher-mileage units.
Still, a full set of records does not mean a motorhome is free of problems. An inspection adds facts that records cannot.
Diesel pushers are complex chassis with many systems to check. That complexity is one reason a professional inspection is often recommended for them.
Visible leaks, low or pinched air bags, and missing grommets or exhaust hangers are often easy to see. Loose wiring and damage at the back of the coach also tend to stand out.
A trained mechanic or inspector can check much more than a quick look covers.
At Test Drive Technologies, an RV inspection may include 100 or more photos, video, diagnostics and checklists. That record gives a buyer a detailed view of the coach's condition before the sale.
Steven is the CEO of Test Drive Technologies based in St. Louis. When he's not busy inspecting and appraising vehicles, he spends time with his family.
Don't risk costly repairs or hidden damage. Know the truth before you buy with certified mobile vehicle inspections and appraisals. Inspecting commercial fleets, RVs, motorhomes, used, luxury and classic cars.
