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Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers

Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers

Item # ML389DAT
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Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers Universal Application Lock ML389DAT
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Customer Photos

Keep your trailer safe from towaway theft with this universal coupler lock. Its tough frame fits in and around most 1-7/8", 2", and 2-5/16" ball couplers; and it has a bright red color and heavy-duty construction to deter theft. Lowest Prices for the best trailer coupler locks from Master Lock. Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers part number ML389DAT can be ordered online at etrailer.com or call 800-298-8924 for expert service.
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  • Reviews (578)
  • Q & A (60)
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  • Why etrailer?

Master Lock Trailer Coupler Locks - ML389DAT

  • Fits 1-7/8 Inch Ball
  • Fits 2 Inch Ball
  • Fits 2-5/16 Inch Ball
  • Master Lock
  • Surround Lock
  • Keyed Unique
  • Universal Application Lock

Keep your trailer safe from towaway theft with this universal coupler lock. Its tough frame fits in and around most 1-7/8", 2", and 2-5/16" ball couplers; and it has a bright red color and heavy-duty construction to deter theft.


Features:

  • Heavy-duty coupler lock deters trailer theft by preventing hookup
  • Large size and heavy weight defend against attempts to break or shatter lock
  • Wafer-tumbler lock mechanism resists picking and prying
  • 1-Piece housing slides to fit tightly around your coupler
  • Powder coat resists rust and corrosion
    • Red color provides a visible theft deterrent
  • Keyway cover protects lock from moisture and debris
  • 2 Keys included


Specs:

  • Application: most 1-7/8", 2" and 2-5/16" couplers
    • Fits standard lip, rolled lip, straight lip, surge brake, hammer blow, and UFP couplers
  • Limited lifetime warranty


Note: This product cannot be keyed alike.


Instructions for Locking the Trailer Coupler

  1. Insert key and turn clockwise to unlock.
  2. Pull the ball out from the lock body as far as it will go.
  3. Insert the ball of the lock into your coupler's ball socket.
  4. Push the lock body in so that it surrounds your coupler.
  5. Turn key counterclockwise to lock.


389DAT Master Lock Universal Trailer Coupler Lock - 1-7/8", 2" and 2-5/16"






Customer Reviews

Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers - ML389DAT

Average Customer Rating:  4.8 out of 5 stars   (578 Customer Reviews)

Keep your trailer safe from towaway theft with this universal coupler lock. Its tough frame fits in and around most 1-7/8", 2", and 2-5/16" ball couplers; and it has a bright red color and heavy-duty construction to deter theft.

- ML389DAT
by:

So happy to get this product. Simple, easy, and ease of mind having it! 546088



- ML389DAT
by:

Works well I like the fact that it`s easy to connect, fits 1-7/8" ball up to 2-5/16" and protects my trailer peace of mind 538504



- ML389DAT
by:

This is just the anti-theft deterrent device we have been looking for. We have an Excavation business and keep a lot of expensive tools and equipment in a 6x12 trailer. We can sleep at night knowing our trailer will still be there in the morning. This thing is very easy to put on and take off. 539334



- ML389DAT
by:

I like the ease of use, however it doesnt fit snug. Almost looks like a couple of well placed sledge hammer hits would knock it off. Probably need something else. 554522


Comments
The sad fact is that locks are only for keeping honest people honest. If a thief is determined to steal your trailer, theyre going to get it. The idea is to provide a deterrent, to make the thief expend energy and make noise in order to defeat the lock. Most thieves are opportunistic, if the trailer isnt easy to steal, theres a good chance theyll move on to one thats easier.
-- Mike L - 08/17/2018

42499

- ML389DAT
by:

My second lock for my other trailer. This is an excellent solid product. It seems like it would be difficult to defeat. I'm sure it can be defeated, but probably not as fast as grabbing my shotgun and racking the slide. 498937



- ML389DAT
by:

Poor design. With pry bar or chisel and hammer it would be easy to break. If your trailer is worth it, spend a couple hundred and by a heavier lock like AMP. 646633


Comments
If a thief is determined enough, just about any lock can eventually be defeated. Given the price point, this particular lock offers a good level of deterrence. The idea of deterrence is to have the thief see the lock on your piece of equipment, at which point hopefully they will move on elsewhere where the pickings are easier.
-- Mike L - 05/25/2019

55742

- ML389DAT
by:

Fortunately no one has ever tried to pry it off or otherwise remove it, but maybe that's because it's a visible deterrent. I like the ease of application, and the locking mechanism works well. The only minor issue is the color seemed to fade in the hot Texas sunlight pretty quickly. But by all accounts, it's working as it was advertised. 409325



- ML389DAT
by:

Device is better than any other lock I use, I like the design, and the peace of mind of knowing that mr crook won't bother taking my trailer. Thank you 396718


Comments
the Master Lock Trailer Coupler is has been working fine, thank you
Vincent - 08/15/2018

42397

- ML389DAT
by:

This is a terrific design since unlike padlocks, can't easily be cut with bolt cutters. I like the bright red color which tells a thief there is a lock to deal with from a distance. I think someone who wants your trailer can probably defeat any system you use, so the goal is to make it tough as possible and I think this lock does that. 287555



- ML389DAT
by:

Held up well through a tough winter. Too bad the paint has faded to a soft pink. Mechanically sound device. Not sure how a slide hammer would fare against the locking mechanism. 431768


Comments
Stll holding strong. Has faded to almost white but I didnt buy it for looks. Gave the locking mechanism a shot of Tri-Flow to keep it working smooth.
Bob H - 09/12/2018

43490

- ML389DAT
by:

This is perfect to protect your trailer. Very easy to put on and take off. Makes me happy every time I look in the back yard and see that red dot on the front of my trailer. Now to get the kayaks secured! 902817



- ML389DAT
by:

Worked as described. Happy with the product. Ordered late Monday, shipped Tuesday, received Thursday. Excellent! 902566



- ML389DAT
by: 10/05/2020

Seems to work well as a theft deterrent, but if someone were to attempt picking the lock they likely wouldn't have much of an issue getting it open. Easy to use, overall great value. 897278



- ML389DAT
by:

Works well 892328



- ML389DAT
by:

Very poor lock... somebody picked the lock in minutes. Looks like a very nice strong design with a typical poor lock By masterlock. Don’t waste your money 881515



- ML389DAT
by:

876678



- ML389DAT
by:

I think I finally found the lock for my trailer that I have been looking for..It is a nice lock and very easy to use...I would highly recommend it... 876372



- ML389DAT
by: 09/07/2020

875333



- ML389DAT
by:

This coupler lock has been one of the best investments that I have made for my company. I recommend this product to any and all trailer owners. 874894



- ML389DAT
by:

Easy to install, works well as a highly visible deterrent for the casual thief. I use this along with a latch lock, a wheel/tire lock, and locking X-chocks to hopefully make my travel trailer annoying enough that they'd just move on to something easier. 872308



- ML389DAT
by:

Great service from etrailer and their staff. Follow up calls and emails in every step. This is missing today with e commerce but not with etrailer. Thank you Carol 876783



- ML389DAT
by:

Great product, is as advertised. 870214



- ML389DAT
by:

I got one of these with a new utility trailer I bought a few years ago. When I need to put a trailer coupler lock for my boat trailer that I have to leave out on the street sometimes I found this on Etrailer AND in Red. So now I have a Red and Silver. Two separate keys but easy to use and nobody is going to hook up my trailer when I am not looking. 870005



- ML389DAT
by: 08/27/2020

Great product and price 869829



- ML389DAT
by:

Easy to install It was not very heavy I like the bright color I do wonder if it would hold up against a big crow bar. 867035


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Show More Reviews

Ask the Experts about this Master Lock Trailer Coupler Locks

  • Coupler Lock for Trailer Coupler with Rolled Lip
    You are absolutely right that the rolled lip on your trailer's coupler will prevent using some types of locks but we do have a solution for you. If your coupler measures no more than 4-1/2-inches wide (including the lip) you can use the Fastway Universal Trailer Coupler Lock # DT25013KA. If it is wider then instead you can use Master Lock # 377DAT. The coupler lip appears too tall to work with lock # ML389DAT.
    view full answer...
  • Best Coupler Lock Options for a 2015 Ranger Trail Boat Trailer
    We have a few different universal options that I recommend choosing from. The Master Lock Trailer Coupler Lock # ML389DAT is a great option because it has a bright red color to draw attention to the fact that there is a lock on the trailer. Since the idea behind a lock is to deter theft, drawing attention to the lock will help to intimidate a would-be trailer thief. One of the most popular options is the Fastway Trailer Coupler Lock # DT25013KA. You can order this lock keyed alike...
    view full answer...
  • Can the Master Lock Trailer Coupler Lock be Keyed Alike
    I have a solution but unfortunately the Master Lock Trailer Coupler Lock part # ML389DAT can not be ordered with a specific key number. Instead the etrailer Trailer Coupler Lock for Flat Lip part # e98895 can be ordered keyed alike. It doesn't work on the 1 7/8" coupler, for that use the etrailer Trailer Coupler Lock part # e98897. These are very nice quality locks that will keep your trailer secured. Check out the video I did on them that I have linked it for you.
    view full answer...
  • Recommended Coupler Lock for a Tie-Down Engineering (TDE) Model 660 Brake Actuator
    I have two recommended options for you to lock the Tie-Down Engineering (TDE) Model 660 Brake Actuator, the Master Lock Trailer Coupler Lock part # ML389DAT or the Fastway Universal Trailer Coupler Lock part # DT25013KA. These are my two favorite trailer coupler locks and they will both work well with your brake actuator. The Master Lock is our most popular option but the Fastway is a bit beefier so this is actually what I recommend for you. The Fastway also has a cover for the lock core...
    view full answer...
  • Multiple Trailer Coupler Locks That Can Be Keyed Alike
    I do have a trailer coupler lock that can be keyed alike but the Master Lock Trailer Coupler Lock part # ML389DAT cannot. Instead you will want to use the Fastway Universal Trailer Coupler Lock part # DT25013KA which can be keyed alike and will work on 1-7/8", 2" and 2-5/16" trailer couplers. This is currently the most cost effective trailer coupler lock we have that can be keyed to match one another. I have attached a review video of the Fastway coupler lock for you as well.
    view full answer...
  • Will Master Lock Coupler Lock # ML389DAT Fit Big Tex 70DM-18 Car Hauler
    The Master Lock Trailer Coupler Lock # ML389DAT will work well on your Big Tex 70DM 18 car trailer. I looked up pictures of the trailer and found that it has a collar lock style coupler which we know this lock works great with. I attached a picture of this lock used on a similar coupler for you to check out as well.
    view full answer...
  • Best Universal Trailer Coupler Lock with Keyed Alike Option
    I do have trailer coupler locks that can be keyed alike no matter how many you purchase but the Master Lock Trailer Coupler Lock part # ML389DAT cannot. For a trailer coupler lock that fits 1-7/8", 2", and 2-5/16" hitch balls and can be keyed alike, I recommend the Fastway Universal Trailer Coupler Lock part # DT25013KA. The Fastway Universal Trailer Coupler Lock is a very versatile device which can fit three different size hitch balls. The tube style locking core makes keys harder to...
    view full answer...
  • Locks for A-Frame Trailer Coupler
    We have all sort of trailer locks including coupler locks for a-frame trailer couplers. Please refer to the linked page that displays all standard coupler locks. You can use a universal-fit surround-type lock such as # ML389DAT which fits all ball sizes and that prevents someone from hitching to your trailer by clocking access to the coupler, or a simple latch type lock like # e98889 that prevents the coupler latch (like the one on # CA-5400-B) from being lifted to unlock the coupler.
    view full answer...
  • Would the Master Lock Trailer Coupler Lock # ML389DAT Fit an Interstate Cargo Trailer
    I looked up some pictures of the couplers that are on Interstate cargo trailers and the Master Lock Trailer Coupler Lock # ML389DAT that you referenced would fit the couplers and would work well. I attached a review video for this lock for you to check out as well.
    view full answer...
  • BestTrailer Coupler Lock for R-Pod Trailer
    The best trailer coupler lock for your 2015 R-Pod R178 - or other R-Pods with a 1-7/8", 2" or 2-5/16" ball coupler for that matter - is the Master Lock Trailer Coupler Lock # ML389DAT. The reason this is the best lock is because it offers the most protection from removal due to its unique design which ensures it won't be able to be pried off, cut off, or hammered off. It is also a bright red so any would-be thieves will know right away you have a trailer that isn't going to be worth...
    view full answer...
  • Will the Master Lock Coupler Lock # ML389DAT Fit a 4 Wide Trailer Coupler
    We do have some options for you but the Master Lock Trailer Coupler Lock # ML389DAT that you referenced has a max coupler width of 3-1/4" so your coupler will be a little too big for it. For a coupler lock that can accommodate a 4" wide coupler we have the following: Tow Ready Gorilla Guard - # 63227 Fastway Universal Coupler Lock - # DT25013KA Master Lock Coupler Lock - # 377DAT etraiiler.com Coupler Lock - # e98895 Out of those options I recommend going with the etrailer lock....
    view full answer...
  • Trailer Coupler Lock Compatibility with Multi-Fit Ball Coupler to Secure Trailer
    The Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers # ML389DAT will work with the Dexter # 099-175-20 which replaced the Titan T47154107K. I recommend setting the multifit coupler for the largest hitch ball setting prior to adding the lock so it will not be removable when loosening the ball connection.
    view full answer...
  • Trailer Coupler Lock to Replace One With no Key
    Replacement keys for trailer coupler locks from this manufacturer were once something that was offered, but because there was so much difficulty getting the correct key they are no longer available. That means the only option if you don't have a key is to cut off your current lock and replace it. The good news is you can get an outstanding coupler lock for a price that is very similar to getting a replacement key. I strongly recommend the Master Lock Trailer Coupler Lock # ML389DAT which...
    view full answer...
  • Locks for 2-5/16-Inch Coupler on Travel Trailer
    We offer many styles of locks for 2-5/16-inch trailer couplers and all of them are shown on the linked page. All are the surround type lock and we have some that fit all coupler sizes, such as the Fastway Universal Trailer Coupler Lock # DT25013KA. For a lock specific to a 2-5/16-inch coupler that completely encases the coupler you might consider the Blaylock # BLTL-23.
    view full answer...
  • Recommended Coupler Lock for UFP A-60 Surge Coupler
    For a UFP A-60 hydraulic actuator/coupler I suggest Fastway coupler lock # DT25013KA or Master Lock # 377DAT but the style of lock # ML389DAT will not work with your coupler.
    view full answer...
  • Key Replacement for ML389 DAT
    You would need the part # MLK1. On the product page you would then need to enter the key number you need and we will ship you out the correct key.
    view full answer...
  • Troubleshooting MasterLock Coupler Lock Where Key Seems Stuck
    Try shooting some WD40 with a straw into the key slot of the Master Lock Trailer Coupler Lock # ML389DAT to see if you can get it to free up stuck tumblers. Most likely that will fix the issue but if not let me know!
    view full answer...
  • Coupler Lock for Vintage Coupler on 1949 Airstream
    Thank you so much for the photos and for your 2" coupler I recommend the Master Lock Trailer Coupler Lock # ML389DAT. This is a heavy-duty and easy to use coupler lock; you only need to put the ball of the lock into the coupler's ball socket, push the body of the lock in and turn the key. I have added links to a pair of video reviews for you to take a look at as well.
    view full answer...
  • Multiple Locks for a 2-5/16 Inch Coupler that Can Be Keyed Alike
    Unfortunatley, the Master Lock Trailer Coupler Lock # ML389DAT cannot be keyed alike. But I do have an option that may work for you. The Fastway Universal Coupler Lock # FA86-0015-303 uses the specifc 303 key code and can be ordered in multiple quantities. There a number of options of different key codes available for you to choose from and any will fit a 2-5/16 inch coupler.
    view full answer...
  • Trailer Coupler Lock For Bulldog Coupler
    When using a bolt-on coupler such as the Bulldog # BD44150WH301, locks such as the Master Lock # ML389DAT help to prevent trailer theft. This product has a 1-Piece housing that slides to fit tightly around your coupler and 2 keys are included.
    view full answer...
  • Recommended Keyed Alike Trailer Coupler Lock for 3 Key Matching Trailer Locks
    The Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers # ML389DAT do not have a keyed alike feature so unfortunately I can't guarantee 3 of these keyed alike. If you are interested in a coupler lock with the keyed alike option, I recommend the Fastway Universal Trailer Coupler Lock for 1-7/8", 2" and 2-5/16" Couplers # DT25013KA. This is a very versatile coupler lock compatible with most styles of trailer couplers. I've attached a video to assist and you can...
    view full answer...
  • Can Master Lock Trailer Coupler Lock be Pried Off
    Realistically, the Master Lock Trailer Coupler Lock # ML389DAT won't be pried off; even if there's enough room to fit a crowbar, getting it fully wedged in so that enough leverage can be applied to the lock to break it off just isn't going to happen. Theoretically, any lock can be busted with enough force but the odds of your trailer getting stolen with this lock on it are extraordinarily slim compared to not having the Master Lock on.
    view full answer...
  • Construction of Master Lock # ML389DAT Trailer Coupler Lock
    The Master Lock # ML389DAT is constructed of steel, as opposed to pot metal. Pot metal is an alloy made of non-ferrous metals with low melting points like zinc, lead, copper, tin and aluminum. The lock wouldn't shatter or crack if struck by a hammer, unless extraordinary means like liquid nitrogen were used on the lock first. Although just about any lock can be defeated by a determined criminal if they are motivated enough and have enough time, the rugged construction of the # ML389DAT...
    view full answer...
  • Trailer Coupler and Wheel Locks to Deter Trailer Theft
    master Lock trailer coupler lock # ML389DAT would be a bit more secure than lock # 377DAT in my opinion because it would be a little more difficult to pry off. When it comes to locks the best solution is redundancy. In other words more than one lock. You may want to consider also adding a wheel lock such as # RA-25 or # WI490. If a thief sees a coupler lock and a wheel lock they are likely going to move on to an easier target.
    view full answer...
  • Trailer Coupler Lock for 1-7/8, 2, and 2-5/16 Inch Couplers that Can be Keyed Alike
    Unfortunately, the two locks you asked about cannot be ordered keyed alike or rekeyed but I do have some options for you. We have some trailer coupler locks that can be ordered in multiple quantities and keyed alike and will fit a 1-7/8, 2, and 2-5/16 inch couplers. The Blaylock EZ Lock Trailer Coupler Lock # BLTL-33-40D is one. It uses a heavy-duty bracket that fits around the coupler. Another option is the Fastway Universal Coupler Lock # FA86-0015-312 which is ordered with the...
    view full answer...
  • Material of the Master Lock Coupler Lock part # ML389DAT
    The Master Lock Coupler Lock part # ML389DAT that you referenced is made of steel. It is basically the red powder coated version of the older Master Lock 379ATPY.
    view full answer...
  • Availability of Keyed Alike Trailer Coupler Lock
    Unfortunately Master Lock doesn't give use the option of offering their # ML389DAT keyed alike. I'd recommend The Universal Trailer Coupler Lock, part # DT25013KA which is available keyed alike. On the linked product page, simply click the 'keyed unique' drop down menu and choose the 'keyed alike' option. I've linked to a product description video that you might find helpful.
    view full answer...
  • Recommended Coupler Lock that is Keyed Alike
    I do have a solution for you, however the Master Lock Trailer Coupler Lock # ML389DAT referenced in your question cannot be keyed alike. For a similar option that can be keyed alike, I recommend looking at the Fastway Universal Trailer Coupler Lock # DT25013KA. Like the Master Lock product you were looking at, this coupler lock is compatible with 1-7/8 inch, 2 inch, and 2-5/16 inch couplers. It features an anti-drill pin to discourage attempts to drill out the lock and a bolt-blocked...
    view full answer...
  • Construction of Master Lock # ML389DAT Coupler Lock
    The Master Lock # ML389DAT trailer coupler lock is constructed of powder coated steel. If you click the provided link, you can see a product demonstration video. As you can see by its rating, the folks who've purchased the lock are happy with it.
    view full answer...

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Info for this part was:

Expert Research:
Mike L
Expert Research:
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Expert Research:
Jameson C
Expert Research:
Adam R
Edited by:
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Video Edited:
Jacob T
Installed by:
Cole B
Updated by:
Danna S
Updated by:
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Written by:
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