Quick Safety Must-Do’s

• Keep hands and fingers clear of the coupling while attaching.
• Attach safety chains while coupling/uncoupling (don’t leave them until last).
• Never use the tow pin or coupling for recovery (snatch/strap recoveries etc.).
• Where possible, couple/uncouple on level ground, with the trailer stable.

Know the Parts

• Tow Pin (on vehicle): The DO35 doesn’t clamp onto a tow ball—your vehicle uses a DO35 tow pin.
• Universal joint (on trailer): Drops over the tow pin.
• Red lock button + locking plate: Controls the lock/unlock position.
• Checklock dust cap: Snaps on after locking to keep dirt out and act as a visual “ready to tow” check.

Before You Hitch Up (30-second checklist)

• Trailer is stable (handbrake on, jockey wheel down, wheels chocked if needed).
• Remove the tow pin cover (if fitted).
• Clean + lightly lubricate the tow pin and universal mating surfaces (dust/sand = wear).
• Confirm your Anderson plug, trailer plug, and breakaway cable are accessible.

How to Hitch Up a DO35 (7 Steps)

1. Remove the tow pin cover from the vehicle tow pin.
2. Check for dirt/sand on the tow pin and universal, and lightly lubricate.
3. Set the coupling to UNLOCKED: push down on the red lock button while sliding the locking plate back toward the button. The centre viewing port should be clear in the unlocked position.
4. Use the jockey wheel/stand to raise the trailer coupling above the tow pin height.
5. Align coupling over the tow pin (move vehicle or trailer), then lower the coupling onto the tow pin using the jockey wheel/stand. Ensure the universal is fully seated on the tow pin and the pin is visible through the view port.
6. Lock it: press the same red lock button to reset the locking plate into the locked position.
7. Fit the Checklock cap: snap the back edge in first, then push down the front until you hear an audible “snap”.

Final “Ready to Tow” Checks

• Safety chains attached correctly and not dragging.
• Breakaway cable attached to the vehicle (not to the safety chains).
• Trailer plug connected and lights working.
• Jockey wheel fully raised/secured, stabilisers up, steps/doors secured.

How to Unhitch (Quick Steps)

1. Park on the most level ground available, apply trailer handbrake, and chock wheels if needed.
2. Lower the jockey wheel until it supports the drawbar.
3. Disconnect electrics (trailer plug/Anderson if applicable) and breakaway cable.
4. Remove the Checklock cap.
5. Unlock: push down the red lock button while sliding the locking plate back to the unlocked position.
6. Raise the trailer with the jockey wheel to lift the coupling off the tow pin.
7. Once separated, refit the tow pin cover (if used) and secure chains so they’re not dragging.

Maintenance & Care

The DO35 is built for harsh conditions, but it still needs basic care to stay smooth and safe.

• Keep tow pin + universal mating surfaces clean and lightly greased.
• Regularly lubricate grease points with a suitable multi-purpose grease.
• Check the tow pin O-ring condition and replace if damaged.
• If the locking mechanism won’t open fully due to dirt, flush with clean water to clear debris.
• If the coupling head becomes excessively loose, it may need adjustment by a competent person.

Using a Weight Distribution Hitch (WDH)

The DO35 can be used with a WDH as long as the coupling movement is not obstructed and the maximum downward load limit is not exceeded. Always check for clearance so the drawbar won’t foul, especially in tight turns/reversing.

Optional: DO35 Security Lock (Dummy Pin + Lock)

If you want extra peace of mind when the trailer is parked, a DO35 security lock kit typically uses a dummy pin that inserts through the universal joint, then a lock body is fitted and keyed—making the coupling inoperable.

Video Walkthrough (Optional)

• Cruisemaster – Hitching Up with the DO35 (YouTube)