Bulldog 580406 Hitch & Coupler Lock Set, 5/8 in
Bulldog 580406 Hitch & Coupler Lock Set, 5/8 in — Product description
The Bulldog 580406 locks down both ends of your towing setup. A 5/8-inch dogbone hitch pin secures the ball mount in a Class III or IV receiver, and a matching coupler lock keeps your trailer latch shut when the boat's parked. Both pieces are keyed and come with dust caps to fight off ramp grit and salt.
The Bulldog 580406 is a two-piece towing security set that locks down both ends of your setup. You get a 5/8-inch dogbone hitch pin for the receiver and a matching coupler lock for the trailer latch. Together they cover the two spots a thief goes for first: the ball mount sitting in your hitch and the coupler that drops onto the ball.
The hitch pin fits Class III and IV receivers, the 2-inch openings you'll find on most trucks and SUVs rigged for a boat trailer. It's the dogbone style, so the locking head sits close to the receiver and there's no long shank hanging out to catch a shin. Slide it through, turn the key, and your ball mount isn't going anywhere without it.
The coupler lock is the part that matters at the ramp and in the driveway. It fills the coupler latch so nobody can drop your trailer onto their ball and tow it off while you're on the water. That's the difference between a trailer that's parked and a trailer that's protected. If you've ever left a rig sitting overnight at a launch, you know why that matters.
Both pieces use a keyed lock, and both come with a dust cap to keep the cylinder clear of road grime, launch-ramp grit, and salt spray. That last part counts if you're backing into brackish or salt water. A lock that seizes up is worse than no lock at all, and the caps go a long way toward keeping the mechanism turning smoothly season after season.
It's a single set, sized for one receiver and one coupler. Good fit for a bass boat, a center console on a tandem-axle trailer, or a small aluminum rig you tow behind the daily driver. Simple. No wiring, no tools. Just two locks and the peace of mind that comes with knowing your boat's still there when you walk back up the ramp.
Key Features
- 5/8-inch dogbone hitch pin fits Class III and IV, 2-inch receivers
- Coupler lock included to secure the trailer latch when the rig is parked
- Keyed locks on both pieces, pull the key and both stay locked
- Dust caps on both locks keep grime and salt out of the key cylinders
- Dogbone head sits close to the receiver, less to snag or grab
- Single set covers one receiver and one coupler
Why Buy from NVN Marine
- Authorized Bulldog reseller, full manufacturer warranty
- NMEA member and ABYC certified, advice from real boat techs
- Same-day shipping before 3 PM ET on in-stock items
- NY headquarters and Fort Lauderdale flagship retail store
Technical specifications
| Title | Bulldog 580406 Hitch and Coupler Lock Set |
|---|---|
| Brand | Bulldog |
| Manufacturer Part Number | 580406 |
| UPC | 783192025845 |
| Fits Hitch Class | Class III / IV |
| Hitch Pin Diameter | 5/8 inch |
| Lock Style | Keyed |
| Lock Design | Dogbone |
| Coupler Lock | Included |
| Dust Cap | Included |
| Quantity | Single |
Frequently asked questions
Are locking hitch pins worth it?
If your boat trailer ever sits unattended at a ramp, a campsite, or a driveway, yes. A locking pin stops someone from pulling your ball mount out of the receiver, and paired with the coupler lock it keeps the whole rig from being hitched and towed off. It's cheap insurance next to what the boat is worth.
What hitches does the 5/8-inch pin fit?
It's sized for Class III and IV receivers, the 2-inch openings common on trucks and SUVs set up for towing. The 5/8-inch diameter is the standard pin size for those receivers.
Does this set lock the trailer coupler too?
Yes. Along with the hitch pin, you get a coupler lock that fills the latch so the coupler can't be dropped onto another ball and towed away while the trailer's parked.
Can I use this on a boat trailer?
That's exactly what it's built for. The hitch pin secures your ball mount and the coupler lock protects the trailer when it's off the truck. Both come with dust caps, which help when you're launching in salt or brackish water.
What does the dogbone style mean?
It describes the shape of the hitch pin lock. The locking head is compact and sits close to the receiver instead of sticking out on a long shank, so there's less to snag and less exposed for someone to grab.
Does it come with dust caps?
Yes. Both the hitch pin and the coupler lock include a dust cap to keep road grime, ramp grit, and salt out of the key cylinder.
