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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

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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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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 800-298-1624 for expert service.
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  • Reviews (689)
  • Q & A (65)
  • Photos
  • Why etrailer?

Master Lock Trailer Coupler Locks

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

Item # ML389DAT






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   (688 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:

Recently bought a boat and the trailer did not have any way to lock the tongue that I could see. After seeing that my stepson had a trailer with this style lock on it and seeing that it would be virtually impossible to pry it off I did some research. I have purchased from etrailer in the past and trust them to only sell the best. I ordered it and received it in a timely manner. It fits perfectly and I now feel my trailer and boat are secure. Who would doubt the Master Lock brand anyway!?!


Comments
Still working great, no complaints here.
Douglas - 12/16/2020


- ML389DAT
by:

Great product. Master Lock brand and quality. Very secure and provides me with peace of mind that it’s a huge deterrent to would-be boat thieves.



- ML389DAT
by:

We purchased this lock based on a recommendation from a friend, as well as the written reviews. It is heavy and substantial, and I am relieved to have an extra layer of protection for our trailer while camping in area's without security. Etrailer comes though yet again.



- ML389DAT
by:

After years of no worry trailer and boat five-fingered discount from bad guys interested in stealing my first unhitched boat using a trailer coupler lock much like this one I now have confidence my new boat will be similarly safe using the bright red Master Coupler Lock. I like the red color which makes it obvious the bad guys need to move on to find another victim.



- ML389DAT
by:

Purchased two of these to replace pin style coupler locks. Decent coupler lock, will probably provide a fair amount of deterrence. However, it does not snuggly fit into either of the trailers I outfitted with these locks. There is a fair amount of wiggle even when adjusted completely. Still looking for a better coupler lock option...



- ML389DAT
by:

Very good product that works well when trailer is unattended.


Comments
Heavy duty and reliable!
Dwayne - 11/04/2021


- ML389DAT
by:

I feel much better about parking my trailer on the street with this lock on the hitch. Not only does it lock up the hitch securely but the bright red color signals to prospective thieves that this trailer cannot be towed. It is easy to attach and easy to remove. Also very compact so it can be stored easily. The shipping time was less than I expected. etrailer.com is my goto supplier for my trailer accessories.



- ML389DAT
by:

We have had this lock for year and love it. It is durable and reliable every time we use it. Our Son and Brother-in-law just bought one because we like ours so much. Awesome product!



- ML389DAT
by:

It's a great deterrent for thieves and peace of mind for you to know that your trailer is safe. Like any devise, it keeps honest people honest. No system is foolproof.



- ML389DAT
by:

The product arrived when promised. It was in excellent condition when I received it. It seems to work very well so far.


Comments
Fine
Michael - 11/07/2021


- 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.



- ML389DAT
by:

I received the Master Lock Trailer Coupler Lock that I ordered. It was delivered in just a few days just a it was supposed to. It is exactly what I was looking for. It will help detour anyone from stealing my trailer ! I am extremely happy with the lock and etrailer ! I think this is a great company with great pricing on there products ! I will recommend them to everybody and will be ordering with them again real soon ! It was an easy and excellent experience. Great customer service too ! Thanks etrailer !



- 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



- ML389DAT
by:

Works great I’m sure if someone would try and steal your trailer they would figure out how to knock it off just like any lock it keeps the honest people honest



- 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.



- ML389DAT
by:

Perfect fit ordered two fit both types of trailers very well.



- ML389DAT
by:

Product appears to he high quality. It fits the hitch well and I expect that it will be good deterrent.


Comments
The lock is working well. I am pleased with my purchase.
Dan - 06/26/2021


- ML389DAT
by:

Quality product, easy to use, highly re commended.



- ML389DAT
by:

Nice tool, I like that it will adjust easily for different depths so it will fit more than one size trailer tongue. It pulls in snug and with a couple firm smacks with a 2 pound hammer is still works just fine.



- ML389DAT
by:

It's a great product. It looks good on the trailer, and you can see it from very afar. And there is no way to saw it off, break it apart, or something like that. The construction is basically rounded, and there is nowhere you can find a starting point to place a saw or breakaway device on it. I have also bought different lock from Reese, and it looks wimpy, and easy to take it apart, or saw it off as some reviews have suggested. It's also easy to put it on and take it off. Just love the product. Here I attach some pictures in the campgrounds, etc.



- ML389DAT
by:

Nice lock. It’s nice that there is nothing to really cut on it. Latches on nice and strong. Easy to use. You could even use a default latch lock with it. Hope it holds up as good as it looks. Will review again after awhile.



- ML389DAT
by:

seem pretty janky, doesn't work great but my trailer hasn't been stolen so there's that.



- ML389DAT
by:

I recently purchased a new bumper hitch camper and this lock pretty much guarantees my camper will stay where I parked it. I like the way it is made.


Comments
Great value for the money. Easy to use and I dont have to worry about someone doing a quick hook and go on my 2020 RV.
Sam K - 01/09/2021


- ML389DAT
by:

This lock was chosen by me for medium security of our 20' boat. I was installed easily and will keep most who want to try to steal something like our boat away. If they really wanted to, a sledge would destroy this. Where there's a will there's a way. For our 31' trailer, I opted for another model. That would take a lot more beating to 'maybe' get off the hitch. It also costs about 8 times as much though...


Comments
After one year, taking it off. Our boat is in use again after 1 year, going to Lake Mead. It has held up great, easy to open, and kept thieves away...
Jerome M - 08/17/2018



- ML389DAT
by:

No issues after a year. It is exposed to the elements and the paint has faded a lot as a result. Functionally, it's still the same as it was the first day.


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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...
    Image 1 for
  • 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...
  • Bolt-On A-Frame 2-5/16 Inch Ball Trailer Coupler For 1973 Airstream
    There is one A-frame coupler that accepts a 2-5/16" hitch ball and fits the bill perfectly that I really like, which is from Demco: - Demco 50-Degree A-Frame Trailer Coupler # DM16680-52 The reason I like this Demco coupler so much is because of its super easy to use latch system, called an eZ-Latch, which just stays closed all the time, until the coupler goes over the hitch ball and it just snaps on. That's all there is to it. This is also a bolt-on coupler like you wanted, and is...
    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...
  • 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...
  • 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...
    Image 1 for
  • Can Master Lock Coupler Lock be Ordered With Specific Key Number
    Locks, including the Master Lock Trailer Coupler Lock # ML389DAT cannot be ordered with specific key numbers, they do come with a random key. I have added a link to a video review for you as well of the Master Lock Trailer Coupler Lock # ML389DAT.
    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...
    Image 1 for
  • 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...
  • 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...
  • 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...
  • 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...
  • 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...
  • 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...
  • 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 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 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...
  • 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...
  • Where to Find a Replacement Key and the Number for a Master Lock Trailer Coupler Lock
    The Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers, part # ML389DAT, would not have the key number printed on the package since they put random ones in each package (printing on the package would make it easier for others to find out your key number). As such, to determine the key number for use with # MLK1, you will need to look at the physical key itself as those are the only place where the number is printed. If you have completely lost your set of keys...
    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...
    Image 1 for Image 2 for
  • 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...
  • Replacement Key for Master Lock ML389DAT Trailer Coupler Lock
    To obtain a replacement key, you'll need to know the 4 digit code that was stamped on the key. You'd use part # MLK1. On the product page, near the 'add to cart' button, you'd need to type in the 4 digit key number.
    view full answer...
    Image 1 for
  • 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...
  • Troubleshooting Key That Wont Turn for Red Master Lock Trailer Coupler Lock
    If you are having trouble unlocking the Master Lock Trailer Coupler Lock # ML389DAT then I recommend using a spray lubricant like WD-40 to help loosen up any dirt or grime that may have gotten in the lock. Let the spray sit in the lock for a few minutes and then try operating it again. If this still doesn't fix the problem then you may need to have a locksmith take a look at it.
    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...
  • 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...
  • 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...
  • 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...

Do you have a question about this Trailer Coupler Lock?




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