If you've shopped for an off-road trailer or camper, you've probably seen the term DO35 hitch — and maybe wondered what it actually is and why people pay a premium for one. Here's a plain-English explanation of the Cruisemaster DO35, how it works, and whether it's the right coupling for your setup.
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What does "DO35" mean?
DO35 stands for "Drop-On 3.5 tonne." "Drop-On" describes how it connects — the coupling literally drops onto a fixed tow pin and locks in place — and "3.5 tonne" is its rated towing capacity (3,500 kg, or about 7,716 lb). It's made by Cruisemaster, and in the US it's commonly called a DO35 hitch, while in Australia it's known as a coupling or coupler. They're the same thing.
How a DO35 hitch works
Unlike a standard ball hitch, the DO35 is a drop-on pin coupling. A tow pin mounts to your tow vehicle; the coupling drops over that pin and locks with a positive two-stage latch. Inside, polyurethane bushes let the coupling move freely on three axes — pitch (nodding up and down), roll (twisting side to side), and yaw (swinging left and right). That full articulation is the whole point: off-road, your tow vehicle and trailer are constantly on different angles, and a rigid coupling would bind and stress the chassis. The DO35 lets the two move independently.
It also includes Cruisemaster's patented Checklock dust cap, which only seats when the lock is properly engaged — a built-in safety check before you tow.
DO35 hitch vs a standard ball hitch
| Standard ball hitch | DO35 drop-on hitch | |
|---|---|---|
| Connection | Trailer cup over a tow ball | Coupling drops onto a fixed tow pin |
| Articulation | Limited — mainly yaw | Full 3-axis (pitch, roll, yaw) |
| Off-road suitability | Can bind and stress the chassis | Designed for rough, uneven terrain |
| Locking | Latch over ball | Positive two-stage lock + Checklock safety cap |
What about the DO45?
The DO45 is the DO35's bigger sibling — same drop-on pin design and full articulation, but rated to 4,500 kg (about 9,921 lb) for heavier rigs, with a larger pin and a wider 4-bolt mounting pattern. Most off-road campers use the DO35; step up to the DO45 only if your loaded trailer exceeds 3,500 kg. For a full breakdown, see our DO35 vs DO45 guide.
Is a DO35 hitch right for you?
A DO35 makes sense if you tow a camper trailer or caravan off sealed roads — gravel, corrugations, steep entry angles, or technical tracks. If your trailer's loaded weight is under 3,500 kg (~7,716 lb) and you want the security and smoothness of a true articulating coupling, the DO35 is the industry standard. If you only ever tow on pavement, a standard ball hitch may be all you need.
Don't forget the tow pin kit
The DO35 connects via a matching tow pin. It's worth keeping a spare — or fitting one to a second tow vehicle — with the DO35 Tow Pin Kit (1" UNF). Towing with a DO45 instead? Use the DO45 Tow Pin Kit — the pins are not interchangeable.
Frequently asked questions
What does DO35 stand for?
"Drop-On 3.5 tonne" — it drops onto a tow pin and is rated to tow 3,500 kg (~7,716 lb).
Is a DO35 a hitch or a coupling?
Both terms refer to the same part. "Hitch" is the common US term; "coupling" or "coupler" is used in Australia.
Can a DO35 tow on-road too?
Yes. It works on sealed roads as well as off-road — the articulation simply isn't needed as much on pavement.
How do I look after a DO35?
Keep it greased and clean, especially after water crossings or dusty travel. See our DO35 maintenance & greasing guide.
Ready to upgrade? Shop the Cruisemaster DO35 and DO45 hitches and genuine tow pin kits at RV Parts Giant — in stock, shipping from Upland, CA.