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  1. Trailer Coupler Locks
  2. Bulldog
  3. Latch Lock
  4. Steel
  5. Keyed Unique
  6. 3/4 Inch Span
Bulldog Lifelong Trailer Coupler Lock - Trigger Latch Style - 1/4" Pin Diameter - Chrome

Bulldog Lifelong Trailer Coupler Lock - Trigger Latch Style - 1/4" Pin Diameter - Chrome

Item # BD580403
Our Price: $27.18
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Trailer Coupler Locks
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Shipping Weight: 0.69 lbs
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BD580403 - 3/4 Inch Span Bulldog Trailer Coupler Locks
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Guard against trailer theft with this durable steel, butterfly-style coupler lock. Works with most ball couplers that have trigger-style latches. Chrome plating resists corrosion, and the unique ball-bearing locking mechanism provides extra security. Great Prices for the best trailer coupler locks from Bulldog. Bulldog Lifelong Trailer Coupler Lock - Trigger Latch Style - 1/4" Pin Diameter - Chrome part number BD580403 can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (428)
  • Q & A (0)
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  • Why etrailer?

Bulldog Trailer Coupler Locks - BD580403

  • Latch Lock
  • Steel
  • Keyed Unique
  • Bulldog
  • 3/4 Inch Span
  • Universal Application Lock

Guard against trailer theft with this durable steel, butterfly-style coupler lock. Works with most ball couplers that have trigger-style latches. Chrome plating resists corrosion, and the unique ball-bearing locking mechanism provides extra security.


  • Coupler lock secures the trigger latch on your trailer's coupler to deter theft
    • Trailer can't be removed from your tow vehicle when locked onto ball
    • Would-be thieves can't secure your unhitched trailer to their tow vehicle
  • Ball-bearing locking system provides maximum security and ease of use
    • Just pop the deadbolt portion onto the end of the pin and the lock will automatically engage
    • Grease ball-bearings periodically to ensure smooth operation
  • Solid steel construction offers superior strength and durability
  • Chrome plating resists rust
  • Plastic cap covers key slot to help prevent corrosion in the locking mechanism
  • 2 High-security, square keys included


  • Application: trigger-latch-style ball couplers
  • Inside pin length (span): approximately 3/4"
  • Pin diameter: 1/4"
  • Limited 1-year warranty

The unique ball-bearing locking system on this Lifelong coupler lock is supremely easy to use. When you pop the deadbolt portion of the lock onto the end of the pin, the integrated ball bearings engage the lock automatically.

580403 Bulldog Life Long Coupler Lock for Trigger-Style Couplers

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Bulldog Lifelong Trailer Coupler Lock - Trigger Latch Style - 1/4" Pin Diameter - Chrome - BD580403

Average Customer Rating:  4.6 out of 5 stars   (428 Customer Reviews)

Guard against trailer theft with this durable steel, butterfly-style coupler lock. Works with most ball couplers that have trigger-style latches. Chrome plating resists corrosion, and the unique ball-bearing locking mechanism provides extra security.


The Bulldog Lifelong Trailer Coupler Lock has been a real failure. At this point, it is non-functional. I would describe my trailer usage as moderate duty, such that I would expect a lock to last more than a year. It started failing at about 6 months, increasingly being difficult to get it to actually lock. At this point, I can't even get it to lock!

My bulldog tire pump, on the other hand, has been awesome! Completely reliable, like most of the products I've purchased from etrailer. I would be glad to give it an excellent review. I would be glad to give your company an excellent review. This particular lock, however, is really poor quality. Total waste of money.

I just thought I should tell you directly rather than post a review of this lock. My review of your company overall would be very high, but my review of this particular lock would be 0 stars.


The lock is made to fit tightly which is appropriate for security. Maybe me, however, was too tight to close over my tongue latch and I couldn’t use it.

You mentioned that it was a too tight of a fit. It sounds like you would need one that had a greater inside span. I would recommend part # e98883
etrailer Adjustable Trailer Coupler Latch Lock - 1/2" to 2-1/2" Span - 1/4" Diameter
which is adjustable from one half to two and a half inches
-- Etrailer Expert Jenny N - 09/07/2022


Worked well but corroded internally quickly unfortunately. Still locked on hitch and can’t be removed without cutting.

Its a shame that this has corroded so soon. I see that this item has a one year warranty, so I sent your information over to our customer service department for them to assist you in getting this item replaced.
-- Etrailer Expert Katrina B - 08/19/2022


broke after 2 months of service. Called for warranty claim - bulldog never responded.

I am more than happy to assist you. I have sent your information over to our customer service department for them to assist you with getting a warranty set up.
-- Etrailer Expert Katrina B - 08/05/2022


Simple design, dont be fooled, it does the job well, secured trailer in the parking lot with decent lighting. Been on several outfits state travels and I am thankful that the reviews were positive, making my choice to purchase this easier. No issues of it being in open weather with its cover,opens every time. No rust to be found. In all, it provides a level of security for my trailer or at least make it real hard to steal.


All components look like they’re built extremely well and I will be confident leaving my trailer when I head out on vacation this September! Thank you for your help and courteous service!


Purchased a trailer for a move from FL to TX and will be stopping along the way.
I Will have my loaded trailer with me and security where I will be staying along the way is unknown. I looked at many hitch locks with my mechanical engineering viewpoint decided this was an excellent choice. With this lock I will sleep well knowing it is unlikely anyone can unhook my trailer.


It stopped working like 2 weeks after i bought it


The lock is currently being used to secure a metal gate with very tight clearance where most locks do not clear. The attached photo shows the lock installed.


It is very easy on and off. fits well and the rubber cap cover for the key slot is a nice idea. Because it's so compact and fits tightly on the hitch it would be harder for a thief to cut off. It's worth having for the extra feeling of security.


Working as expected.




I purchased this item to use with a 7'x16' trailer which carried my family's household belongings across the country last year. The trailer had a 2-5/16" ball. The reason I mention these dimensions is that this lock didn't fit on my trailer. The shaft was too short for my trailer. I ended up not using a lock and just unhitched and secured the trailer with a coupler lock every night during the trip. I gave this item to a friend who owns a smaller trailer. He loves it.

I watch the Lock Picking Lawyer online, and I see patterns as I watch those videos. I purchased this lock because of the following:
1. The locking shaft is hidden when locked making physical attack more difficult.
2. Hardened steel body construction
3. Disc detainer core which requires special tools and skills to pick.

TLDR; If it fits, I believe you'll be pleased. If you have a larger trailer, it may not fit.


a good quality lock.


Exactly what I was looking for with the cover that goes over the lock


Quick delivery, product as advertised


Good quality product, excellent customer service with this company. I will definitely order from them again!


one star off for heavy plastic zip ties that required saw to cut thru... why make these things so thick you could cut your hand off getting out of the packaging.? Lock fantastically built and engineered. Heavy and very strong. Good job...ditch the zip ties


These locks performed horribly, the three I purchased had all become impossible to unlock and remove from the trailer coupler. I had to cut them off with a grinder/cut-off wheel. That being said, I was delayed hooking up my trailer 45 minutes by the time I got the lock removed. The stainless steel ones I had prior held up great. These were a waste of money.


Very good looking product and good quality. A must have.


I own several of these. These coupler locks are good because they require the key to unlock but you can then lock them without the key by pressing the button. They are fairly weather resistant, although the metal pin that goes into the coupler is mild steel and will rust quickly. If that pin were stainless the lock would be improved.


This lock works and performs just like the receiver lock. The ball bearings will need a slight coating of grease to keep things moving over the long haul. I only wish this was made in Stainless Steel to match the other lock. Having just received this, I will update in the future if any problems appear. Extremely happy with speed of delivery and availability of these locks.


I got two of these since I needed locks on two trailers. They function differently than similar locks I have used in the past. The lock is a plunger type that uses the key to press in and lock it shut.

Both of the locks required a lot of wiggling and turning to get to lock. They appear to have crude tolerances and a lot of play, requiring exact lining up to close. I put a little lube in the lock and ball mechanism and it helped. I was not able to pull them apart by hand once locked. They do unlock easily with the key.

I know they aren't the best quality by the price I paid and they are made in China. I am tempted to pry or hammer on one a bit to see if it opens. If it does, I will just chalk it up to knowing better than buying cheap and replace both with higher quality locks. If it holds up, I will say I got my money's worth.

E-Trailer does have excellent communication regarding sales and shipment. I have bought from them in the past and will in the future, no matter what the final verdict is on these particular locks.


Purchased two trailer coupler locks for a new travel trailer. The locks arrived in 5 days and were exactly as described. This is my first purchase with ''. I am sure there will be more purchases in the future. Nice site and easy to navigate.


Lock shackle too short to use on my trailer. I'll try to find use for it somewhere.

Thank you for your review. The pin span is approximately three quarters of an inch. If the latch is thicker than that you will need a longer pin like part e98886.
-- Etrailer Expert Heather A - 03/19/2021

Show More Reviews

See what our Experts say about this Bulldog Trailer Coupler Locks

  • Stainless Steel Coupler Lock Availability
    There are other manufacturers who make stainless steel coupler locks, but Bulldog is not one of them. I attached a page that has all of the stainless steel coupler locks we offer. None of them are the exact same style as the part # BD580403 that you referenced, but there are some similar ones that could work.
    view full answer...
  • Recommended Pin Lock for Trailer Coupler
    The Bulldog Lifelong Trailer Coupler Lock part # BD580403 is an excellent option to secure a trailer. It will prevent the trailer from being coupled as well as preventing the trailer from being uncoupled. The ball-bearing design really makes for a smooth action and operation. Atwood is no longer in business.
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  • Replacement Keys For Bulldog Coupler Lock # BD580404
    Though we do not sell the replacement keys individually the only way we can help you is if you purchase The whole Bulldog Lifelong Trigger-Style Coupler Lock and 2 inch Trailer Hitch Receiver Lock - Chrome # BD580404 again I attached a review video link below.
    view full answer...
  • 2-1/2 Inch Span Bulldog Lifelong Hitch Lock Recommendation
    For a longer version of the hitch lock that comes with the part # BD580404 you would want the part # BD580402 as it has a 2-1/2 inch span. For the matching trigger latch lock as well you would want the part # BD580403.
    view full answer...
  • Can Pintle of B&W Tow and Stow # BWTS10056 Be Moved Down to Lock Coupler Onto Trailer Ball
    Due to the thickness of the top of the coupler, you wouldn't be able to lower the pintle all the way when used on a regular coupler. You'd be better off using a coupler lock to prevent the coupler from being unhooked. The best lock for you will depend on the design of your coupler. If you have a latch style, a lock like the Bulldog # BD580403 would be an excellent choice, and could be used while towing. To view a product demonstration video of the ball I recommended, click the provided link.
    view full answer...
  • Recommended Trailer Hitch Lock and Trailer Coupler Lock
    For your 2020 Chevy Silverado 3500 with 2-1/2 inch trailer hitch receiver I recommend the etrailer Hitch Receiver Lock for 2" and 2-1/2" Hitches - Flush - 3-5/8" Span - Chrome # e98881 and then the Bulldog Lifelong Trailer Coupler Lock - Trigger Latch Style - 1/4" Pin Diameter - Chrome # BD580403. These are great locks that will help deter theft. Unfortunately we do not currently have any keyed alike options compatible with 2-1/2 inch trailer hitch receivers. I recommend keeping the...
    view full answer...
  • Trigger Latch Lock Recommendation for Demco Coupler with Trigger Latch
    We have a really great solution for a lock for the latch of the Demco Coupler part # DM12925 that you referenced with the Bulldog Lifelong Trailer Coupler Lock # BD580403 that fits tight to the coupler trigger making it very hard to get into. The span on this is 3/4 inch which is the same width as the Demco trigger. I attached a picture of the lock installed as well as a review video for you to check out as well.
    view full answer...
    Image 1 for
  • Lock Recommendation for Fitting Pin on Trigger Latch Coupler
    Sounds like you are looking for a lock for the trigger latch of your coupler. For that we have the Bulldog Lifelong Coupler Lock part # BD580403 designed for this which has a pin diameter of 1/4 inch.
    view full answer...
  • Coupler Lock for Titan # T43329007K Brake Actuating Trailer Coupler
    The Bulldog coupler lock you referred to, part # BD580403 would not fit the Titan Brake Actuating Coupler you mentioned. The lock simply is not compatible with that style of coupler. A better choice would be a Universal Coupler Lock like the Fastway # DT25013KA. I have linked you to a product demonstration video showing how the lock works. To view the video, simply click the link.
    view full answer...
  • Recommended Trailer Coupler Locks Keyed Alike
    If you are looking for keyed alike coupler locks, I recommend the Fastway Universal Trailer Coupler Lock # DT25013KA. This will keep anyone from connecting to your trailer and taking it away. I've attached a video to help with this design and function. If you are looking for a trigger lock, then I recommend the Bulldog # BD580403. There isn't a keyed alike option for these locks.
    view full answer...
  • Recommended Trailer Coupler Locks That Can Be Keyed Alike
    I have another option for you, but there is not a way to get 5 of the Bulldog Lifelong Trailer Coupler Lock # BD580403 keyed alike. Instead I recommend the etrailer Trailer Coupler Latch Lock in Stainless Steel # e98890 or Chrome # e98889 which can be keyed alike. All you will need to do is select the keyed alike option from the drop down menu, and change the quantity to 5 before adding them to your cart. I included a video of the etrailer # e98890 and # e98889 for you to take a look at.
    view full answer...
  • Replacement Keys for Bulldog Lifelong Trailer Coupler Latch Lock
    Unfortunately, the Bulldog Life Locks like part # BD580403 are uniquely keyed and replacement keys aren't available. Your best bet would be to cut the lock off and replace it. The etrailer brand locks are available keyed alike if you wish, so you could get a locking hitch pin like # e98882 and a latch lock like # e98890 that are keyed alike. If you write down the key number, and put it in a safe place (but not so safe that you can't find it later), we can get replacement keys for you if...
    view full answer...
  • Comparing the Stainless Steel Trailer Coupler Lock e98890 and Trailer Coupler Lock e98889
    The Stainless Steel Trailer Coupler Lock part # e98890 is made of stainless steel, not chrome plated which is why it is more expensive than the Trailer Coupler Lock part # e98889 which is chrome plated steel. The stainless steel option is better as you don't run the risk of the chrome plating chipping and exposing unprotected steel. In regards to the Bulldog Lifelong Trailer Coupler Lock part # BD580403, this will work with pretty much any trigger style latch with a 1/4" diameter pin...
    view full answer...
  • Anti-Theft Lock Recommendations for Yakima EasyRider Double Decker Trailer # Y08129
    I can definitely help come up with a way to make the Yakima EasyRider Double Decker Trailer # Y08129 as theft resistant as possible but I can't safely recommend you replace the hardware that secures the coupler or hinge to the trailer tongue with hitch locks of any kind. You have to use the included hardware otherwise the warranty of the trailer would be voided and you'd be potentially unsafe to yourself and other motorists. So for the latch of the coupler you could use a trigger latch...
    view full answer...
  • Recommended Trailer Coupler Locks for Open Car Hauler
    We have numerous hitch and coupler locks available. I'm assuming you're looking for a coupler lock that would prevent somebody from hitching your trailer up and taking off with it, is that correct? If your trailer uses a simple latch style coupler like part # BD580403. The locking pin would insert through the hole in the coupler latch, and would prevent the coupler from being opened. If the coupler has a flange around it's lower edge, something like our # e98893 would work well on 1-7/8...
    view full answer...
  • Trailer Coupler Latch Lock with a 1/4 Inch Diameter Pin Longer than 3/4 Inches
    We have several latch locks that have longer pins you could use. Master Lock Adjustable Trailer Coupler Lock - Stainless Steel Item # 2847DAT has an adjustable span of 9/16" to 2-3/4". Stainless Steel Trailer Coupler Lock # e98890 has a span of 7/8" as does lock # 2878DAT. I have linked videos of these locks for you.
    view full answer...
  • Recommendation for Most Secure Trailer Coupler Lock
    The more secure coupler locks we offer are designed for be used when the trailer isn't hitched to the vehicle. They're designed to prevent the coupler from being hitched to a trailer ball, like # FA86-0015-305. With the trailer attached to the ball, you'd want to use something that would prevent the latch mechanism of the coupler from being opened, as well as securing the ball mount into the hitch receiver using something like the # BD580402 hitch lock you'd looked at. The latch locks...
    view full answer...
  • Trailer Coupler Latch Lock with 1 Inch Pin Span
    Master Lock has an adjustable latch lock, # 2847DAT that has presets for either a 1 inch span or a 2 inch span. We also have some that are 7/8 inch spans which is 1/8 of an inch more than a 3/4. We have # e98890, # 2878DAT, and # e98889. I have linked some video reviews of these locks for you.
    view full answer...
  • Recommended Hitch Lock and Coupler Lock Incorporating Safety Chains
    I am not aware of any chain lock. We do have some ball mounts like the B&W Tow & Stow 3-Ball Mount - 2" Hitch - 5" Drop, 5-1/2" Rise - 10K - Black # BWTS10048B which when using a locking hitch pin like # 63232 will secure the shank and ball to the hitch receiver. The Curt Channel Style # C45900 will also secure the ball and mount using # C23556. If you want to secure a coupler to the ball you can use # BD580403. If you really want to secure your chains, you can use a cable lock like...
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  • Recommended Gooseneck Coupler Lock for Puma Trailer
    We have a few different options depending on the gooseneck coupler you have on your Puma trailer. If you have a Bulldog, Stallion, Superior, or T.E.M. coupler then I recommend the Blaylock EZ Lock Gooseneck Coupler Lock # BLTL-50-40D. If you have a RAM coupler then you would need the # BLTL-55-40D instead. Both of these have an option to come with the Blaylock EZ Lock for Set Screw on Gooseneck Coupler - Aluminum # BLTL-51-40D. You would need the # BLTL-53-40D2 or # BLTL-57-40D2. The...
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