The Cruisemaster DO45 is the bigger sibling of the DO35 — same multi-axis articulation mechanism, higher load rating, higher price. If you're deciding between the two, the question is whether your van actually needs the DO45's extra capacity.
DO35 vs DO45: The Key Numbers
| DO35 | DO45 | |
|---|---|---|
| Max ATM | 3,500 kg | 4,500 kg |
| Max tow ball weight | 350 kg | 450 kg |
| Weight (head) | ~2.4 kg | ~3.1 kg |
| Articulation | Full multi-axis | Full multi-axis |
| Price | $580–680 | $700–820 |
Who Actually Needs the DO45?
The DO45 is necessary when your loaded ATM exceeds 3,500 kg or tow ball weight exceeds 350 kg.
Right choice for: Black Series HQ19 or HQ21 loaded near ATM (3,500–4,000 kg loaded), HQ22T (typically well over 3,500 kg ATM), vans with extensive A-frame equipment pushing the nose weight up.
Don't need it: HQ12, HQ15, HQ17 owners. Camper trailers under 2,500 kg ATM. Any van where measured tow ball weight is under 300 kg loaded.
Rule of thumb: Weigh your nose weight loaded as you'd travel. Under 280 kg — DO35 has plenty of margin. Above 300 kg and approaching 3,500 kg ATM — fit the DO45.
Real-World Performance
We've run the DO45 on a fully-loaded HQ19 (ATM 3,650 kg) across 8,000 km of mixed terrain including the Gibb River Road, the Oodnadatta Track, and a section of the Simpson Desert.
Articulation: Identical feel to the DO35. Smooth, progressive, and noticeably better than a standard ball coupling on rough terrain. No flex, no creaking, no play development over 8,000 km of hard use.
Water crossings: Submerged to approximately 400mm depth in creek crossings with no subsequent binding or roughness.
Lubrication: We greased at 5,000 km as recommended. Takes 5 minutes. Slightly increased resistance in articulation noticed at around 4,000 km without re-greasing — disappeared immediately after greasing.
Reverse Manoeuvrability
This applies to both DO35 and DO45 — it's a characteristic of the design. The DO mechanism resists reversing at tight angles more than a standard coupling. Reversing into a standard campsite bay with smooth movements is fine; tight 3-point reversals into off-camber spots require more patience. Experienced owners adapt quickly.
Verdict
The DO45 does exactly what Cruisemaster claims. The $120–140 premium over the DO35 is easily justified when the alternative is fitting an undersized coupling to a heavy van.
Buy the DO45 if: your van's loaded ATM is in the 3,500–4,500 kg range, or your tow ball weight exceeds 300 kg.
Buy the DO35 if: your van sits comfortably within 3,500 kg ATM when loaded.
Shop Cruisemaster DO35 and DO45 at RV Parts Giant.