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Blue Ox Trailer Coupler Lock

Blue Ox Trailer Coupler Lock

Item # BX88351
Our Price: $49.98
You Save: 18%
Trailer Coupler Locks
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Shipping Weight: 2 lbs
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Keep your trailer safe from theft with this universal coupler lock that features a dual-ratchet locking system. Its tough frame fits 1-7/8", 2", and 2-5/16" ball couplers. Lowest Prices for the best trailer coupler locks from Blue Ox. Blue Ox Trailer Coupler Lock part number BX88351 can be ordered online at or call 1-636-306-4830 for expert service.
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  • Reviews (21)
  • Q & A (0)
  • Videos (2)
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Blue Ox Trailer Coupler Locks - BX88351

  • Fits 1-7/8 Inch Ball
  • Fits 2 Inch Ball
  • Fits 2-5/16 Inch Ball
  • Steel
  • Surround Lock
  • Blue Ox
  • Universal Application Lock

Keep your trailer safe from theft with this universal coupler lock that features a dual-ratchet locking system. Its tough frame fits 1-7/8", 2", and 2-5/16" ball couplers.


  • Universal coupler lock fits 1-7/8", 2", and 2-5/16" hitch balls
  • Works with all coupler types
    • Accepts couplers with a lip that is 4" wide or smaller
  • Provides 360 degrees of protection
  • Dual-ratchet locking system
  • Narrow body with 1/2" hardened steel shackle
  • Includes 2 keys

BX88351 BlueOx Trailer Coupler Lock

Video of Blue Ox Trailer Coupler Lock

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Blue Ox Trailer Coupler Lock Review

Randy: Hey guys, Randy here at Today we're taking a look at a Blue Ox coupler lock. This is designed to work with 1-7/8", 2", or 2-5/16" couplers. There's a few exceptions to that. The really big rolled lip, 2-5/16" couplers, it doesn't work with. And it doesn't work with 2" surge couplers that have the lever that comes down on top.Outside of that, as you'll see, we've been through a lot of trailers here in the yard and we haven't really found too many exceptions to that.

It's a really nice, well built coupler. I think this is going to protect your trailer whether you're storing it at home, you're storing it in a storage lot, whatever your cases may be. It's going to do a good job of deterring theft.Now, any lock can be bypassed. It just is what it is. But they do use a nice rounded-style key rather than just a flat key that goes in that can be a little bit more susceptible to being picked.

This one's going to use the core here. Now the core has seven pins in which the key pushes in a certain point that unlocks it and locks it. It's a really nice, smooth operation. You can see that's going to come off there, undo our latch, have that come out there. You can see where the ball is here.Now this is a lightweight aluminum.

It's not so lightweight that you can just hit it with a hammer or break it or anything. Then we've got the hardened hoop on the top. This is the part that most people are going to go after when they try to maybe disable a lock. See it just slides together really nice and easily, able to push down on it. With this being hardened, again, that's going to give us very good durability.It also locks on both sides.

There's a locking arm on this side and on this side. That's common on a lot of the coupler locks, but there are a few out there that just lock on one side. Having that additional lock on the other side of that additional catch just doubles the strength that it has.Another thing I like about the lock is that our key's going to go in one direction, and you can see it's spring-loaded so it's going to spring back. That's going to prevent us from removing the key and accidentally leaving it unlocked. It's always going to be locked when we take that key out.Now the installation process is really simple. Of course you'll want both pieces. You're going to come up to our coupler, place this in, and in most cases you'll want to latch it. That'll hold that base in. We can then take our upper hoop, just press that down in. We want to get it as tight as we can to reduce any movement or wiggle. At that point we've got our trailer protected.Now then working with customers, I've heard a lot of good things about the lock. It's very durable, it works for a long time, you don't have to worry about corrosion and stuff like that causing you any issues. There is a common question I get on coupler locks, and that is if they can be keyed alike. If you had multiple trailers, can you buy three or four of these and have the same key on all of them With the Blue Ox, you can't. That's not an option, but we do have an option for that if you're looking for it. It's from Fastway, it's the universal coupler lock, part number DT25013KA. That can be keyed alike for as many as you want. You can just have one set of keys, and whichever trailer you need that day, unlock it and hit the road.Now we've gone over all the basics of it. Now let's just head down the line on the different trailers and see what it's going to work out for and what it doesn't. Here you can see on a surge-style coupler, even with the twist lock handle here, does a good job fitting on there, holds in place really well. Won't have to worry about that coming off either.Now on the larger rolled lip couplers like this, 2-5/16, you'll see our hoop will not go all the way around. This isn't an application you want to try to use this lock on. On our traditional 2" coupler, you can see not a big lip that goes around there or a rolled lip. Works out really well. Won't have to worry about it coming off.Here on our 2" flat lip coupler, it works out really well. Very secure, very little movement. I think it's a really good fit on there. Here we've got a 2" coupler with the flat lip around it. It's got more of the horseshoe or the slide type top. As you can see, that's also a really good fit. Here you can see, again, a really nice, secure fit. We've got our latch down. I like the latch down. It seems to tighten it up quite a bit. But nice snug fit all the way around. Think it'll work out great in this type of application.As you guys can see, it's a very quick, easy, and effective way to deter theft on your trailer. For your trailer's stored in an area if you don't keep it inside, or maybe you're just in a higher theft area, think it's a great idea.

Customer Satisfaction Score:

Customer Reviews

Blue Ox Trailer Coupler Lock - BX88351

Average Customer Rating:  4.4 out of 5 stars   (21 Customer Reviews)

Keep your trailer safe from theft with this universal coupler lock that features a dual-ratchet locking system. Its tough frame fits 1-7/8", 2", and 2-5/16" ball couplers.


Was purchased with etrailer consult. Fits the 25k Bull Dog cast coupler, however, so much slop it could easily be pried off the coupler. Definitely not recommended for this cast Bull Dog coupler.


Works perfect


Fits perfect on my home-built utility t railer.


Feels a little light for durability but should do the job


Solid lock and fits my 1987 trailer.


My trailer sits outside. The lock gets sticky, hard to turn, freezes up & won't open. Warm it up or WD it, then it works again.


Great product & durable, but a little more expensive than others by $20, I would suggest looking else where first.


Package came when was expected. The product is exactly what I wanted to ensure my rv trailer is secure when parked.


Enjoyed the prompt service and quality product!


Fast shipment.


Greg was great to work with and as always service and shipment were top notch.




Great product, great customer service and fast delivery.









See what our Experts say about this Blue Ox Trailer Coupler Locks

  • Best Wraparound Trailer Coupler Lock with 5" Wide Lip
    The trailer coupler lock I recommend for a trailer coupler with large lip is the Master Lock Universal Trailer Coupler Lock part # 379DAT because the lock does not span the width of the coupler therefore the large lip is not nearly as much of an issue. The Blue Ox Trailer Coupler Lock part # BX88351 and options like it max out at around 4-3/4" wide.
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  • Recommended Coupler Lock That Can Be Keyed Alike
    I do have a great option for you, however the Blu Ox Trailer Coupler Lock # BX88351 that you referenced cannot be keyed alike with other units. If you were to order 7 of these locks you may get 7 different lock cores/keys. For a similar coupler lock that can be ordered keyed alike I highly recommend the Fastway Universal Trailer Coupler Lock # DT25013KA, which like the Bulldog model will fit 1-7/8", 2", and 2-5/16" hitch balls. It features an anti-drill pin that discourages drilling out...
    view full answer...
  • Recommended Keyed Alike Trailer Coupler Lock
    I have a solution for you but the Blue Ox Trailer Coupler Lock item # BX88351 is not capable of being keyed alike. Instead you will want the Fastway Universal Coupler Lock item # FA86-0015-316. This coupler has the same abilities and functions. It fits most 1-7/8", 2" and 2-5/16" ball couplers. You will want to order as many of these couplers as you need and they will all be able to secure with the same key.
    view full answer...
  • Best Coupler Lock for Bulldog Cast Head 2-5/16 Coupler
    The coupler you are referring to is the Bulldog Cast Head Coupler - 2-5/16" Ball # BD4425000317, and there are a couple of options for very high-quality coupler locks for this coupler, with the absolute best being from AMPLock: - AMPLock Trailer Coupler Lock for 2-5/16" Ball Couplers w/o Lip # AMP34FR This lock is a beast for a number of reasons, starting with its ductile cast iron construction. Ductile cast iron is just not going to be something a thief is able to cut through or smash...
    view full answer...
  • How To Lock Dexter DX7.5 Drop-N-Go Brake Actuator While Not In Use
    The best way to lock and secure the Dexter DX7.5 Drop-N-Go Brake Actuator part # 099-175-20 while not in use would be to use a wrap-around coupler lock like the Blue Ox Trailer Coupler Lock part # BX88351. If you want to lock the trailer to the vehicle while not in use then you can use a pin lock like the etrailer Surge Brake Coupler Lock part # e98888.
    view full answer...
  • Availability of Two Sets of Keyed Alike Universal Trailer Coupler Locks
    I'd recommend the Fastway Universal Coupler Lock, part # FA86-0015-312 and # FA86-0015-310. Both are available in multiple units, and would give you two keyed alike sets, with both sets using a unique key. The lock is compatible with 1-7/8, 2 or 2-5/16 inch couplers.
    view full answer...

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Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Lindsey S
Written by:
Lindsey S
Employee Kathleen M
Installed by:
Kathleen M
Employee Randy B
Installed by:
Randy B
Employee Chris R
Video Edited:
Chris R
Employee Wilson B
Updated by:
Wilson B
Employee Mike S
Updated by:
Mike S
Employee Jonathan Y
Video by:
Jonathan Y

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