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Master Lock 1-7/8", 2", and 2-5/16" Trailer Coupler Lock - Nickel Plated Zinc

Master Lock 1-7/8", 2", and 2-5/16" Trailer Coupler Lock - Nickel Plated Zinc

Item # 377DAT
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Trailer Coupler Locks
Shipping Weight: 4 lbs
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377DAT - Fits 1-7/8 Inch Ball,Fits 2 Inch Ball,Fits 2-5/16 Inch Ball Master Lock Trailer Coupler Locks
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Nickel-plated die-cast zinc trailer coupler lock guards against trailer towaway theft. Fits most 1-7/8", 2", and 2-5/16" ball diameters. Lowest Prices for the best trailer coupler locks from Master Lock. Master Lock 1-7/8", 2", and 2-5/16" Trailer Coupler Lock - Nickel Plated Zinc part number 377DAT can be ordered online at etrailer.com or call 800-298-8924 for expert service.
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  • Reviews (139)
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Master Lock Trailer Coupler Locks - 377DAT

  • 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

Nickel-plated die-cast zinc trailer coupler lock guards against trailer towaway theft. Fits most 1-7/8", 2", and 2-5/16" ball diameters.


Features:

  • Coupler lock deters theft of your trailer
  • Fits most 1-7/8", 2", and 2-5/16" ball diameters of the following coupler brands:
    • Reese, Fulton, Valley, Atwood, Putnam, Marvel, Ideal, Acme, Dutton-Lainson
  • Advanced locking mechanism resists picking and prying
  • Easy to install and remove
  • Nickel-plated die-cast zinc resists rust and corrosion
  • Lifetime guarantee


377DAT Master Lock 1-7/8", 2", and 2-5/16" Trailer Coupler Lock - Nickel Plated Diecast Zinc





Video of Master Lock 1-7/8", 2", and 2-5/16" Trailer Coupler Lock - Nickel Plated Zinc

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




Video Transcript for Master Lock Trailer Coupler Lock Review

Dustin: Hey, Dustin here at etrailer.com. Today we've got the master lock trailer coupler lock to take a look at with you.This lock is designed to fit in your coupler ball socket, preventing anyone from hooking up to your trailer and taking off with it. It has a heavy duty nickel plating. Since it's going to be outside, most likely. It's going to help prevent rust and corrosion. It has a heavy duty metal construction, making it difficult to pry off or remove from your trailer without the included keys.

Two keys are included. When I take it off here, you'll be able to see what really makes it work. There's this ball here inside that fits up inside. It's going to help you secure most couplers. I've got 2-5/16ths coupler here on a travel trailer.

Or the 2 inch coupler here on our John boat. Or even the inch and 7/8ths coupler here on our little dump trailer.Now if your coupler has a larger lift like our trailer here it might not be a good fit. To install it you'll just put the ball in place, you can latch down your coupler and the you can engage the lock. Clip it in place, there's nowhere to really pry or press or pull to get it off. Now sometimes people will secure their couplers by placing a padlock with a pin hole coupler latch.

That can be an effective deterrent, but padlocks can easily be cut or pried out, whereas this isn't going anywhere.


Customer Reviews

Master Lock 1-7/8", 2", and 2-5/16" Trailer Coupler Lock - Nickel Plated Zinc - 377DAT

Average Customer Rating:  4.8 out of 5 stars   (139 Customer Reviews)

Nickel-plated die-cast zinc trailer coupler lock guards against trailer towaway theft. Fits most 1-7/8", 2", and 2-5/16" ball diameters.

- 377DAT
by:

Great service and fast shipping. Product came exactly as advertised. 519263



- 377DAT
by:

Picture of lock. 26495



- 377DAT
by:

Really pleased with this lock, with them keyed alike is convenient, used on 2 of my trailers and they seem to be very secure. Would recommend these. 663466



- 377DAT
by:

Product was exactlly what I ordered and expected. I purchased 2 locks and requested they be "keyed alike". I received the locks (that worked great, and were keyed alike) very quickly. I got several emails from real people that let me know the status of the shipping. This is the first time I have purchased a product from etrailer.com, but it will not be the last. The cost was 25% cheaper than retail. I could not find the product on retailers shelves. I found the product, saved money, and got it fast with etrailer.com 66300



- 377DAT
by:

They can be broken very easily. it's not the best product around. 597752


Comments
The truth is, just about any lock can be pretty easily defeated by somebody who knows what theyre doing. A lock such as this will provide a certain level of deterrence, which hopefully will encourage the thief to move on to easier pickings. The best practice is to use a coupler lock such as this one, along with a secondary method such as chaining the trailer to a nearby immovable object or using a wheel lock. The more deterrence you can provide, the better the chances that all but the most determined thief will move on elsewhere.
-- Mike L - 01/16/2019

48618

- 377DAT
by:

Very robust product other than the ball is sized to fit a 1 7/8" coupler as well as a 2" coupler so the fit is a bit loose when installed in a 2" coupler. Would be a better product if it was available for the exact sized coupler that a person needed. 429884



- 377DAT
by:

Easy to use. Does the job when trailer is parked. Keeps honest people honest. Visually says “ you can’t take this “ 863109



- 377DAT
by:

Love it . 856343



- 377DAT
by:

Good quality and heavy duty. Not exactly what I ordered as this lock does not work on my hitch. It will work on my other trailers. 856084



- 377DAT
by:

Works good. A little tight on the 1 7/16. But it works. Will b good peace of mind. 850484



- 377DAT
by:

It's a nice product fits tight still use lock latch also for more security. 850335



- 377DAT
by:

Works great! 837018



- 377DAT
by:

Works perfectly for our teardrop camper hitch. Very happy with the product. We also purchased several other items at the same time and everything worked perfectly and everything showed up as promised. 837422



- 377DAT
by:

Good quality and still holding up a year later 822183



- 377DAT
by:

trailer will be there when i come home or where i leave it 822027



- 377DAT
by:

Good unit, however it did not fit by hi tch 818863



- 377DAT
by:

product would not work on trailer intially intended for but was able to use on my boat trailer. easy to install and believe it should do the job 812166



- 377DAT
by:

VERY NICE FINISH. SEEM HEAVY DUTY. 796340



- 377DAT
by:

Well designed product that cannot be busted off with a hammer like other brands that have a hardened steel U bolt locked into a cast aluminum base. We recently had two 16' trailers stolen from out church simply by busting off the coupler lock with a hammer. I like the design of this product as I was in the process of building one myself until I found this one on your site. I like the brand of the other product for their ball mounts, balls, and hitches, but their coupler lock is junk to me. This lock is a gift for my son for his new pull behind camper. 795459



- 377DAT
by:

Great delivery time as i requested on time. I inspected and have used all products and they were advertised correctly and preformed as indicated in web page. I would highly recommend this company to all my boating friends, They also inspected the products and requested information from me. THX 792681



- 377DAT
by:

Well made product, ordered 4 and worked great on my rv and horse trailer..other 2 will be for gifts! 791646



- 377DAT
by:

I needed to secure my utility trailer from theft. I think this will take care of that need. Very well made product. I expect many years of use. 772945



- 377DAT
by:

Great product. Fair pricing and fast sh ipping. 747686



- 377DAT
by:

great services got product fast. 747044



- 377DAT
by:

Excellent product, very well made and heavy duty construction. Like all products I've purchase at etrailer it's the best! 746230


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Show More Reviews

Ask the Experts about this Master Lock Trailer Coupler Locks

  • Trailer Coupler Lock for 2019 Jayco Jay Flight 28BHBE
    Looks like you have a standard underslung thumb latch coupler like the part # CA-5335-B. The Master Lock coupler lock part # 377DAT would fit this and work well.
    view full answer...
  • Recommended Trailer Coupler Lock for Coupler with 5" Wide Lip
    The best ball style trailer coupler lock we offer for a trailer with extra wide lip is the Master Lock 1-7/8", 2", and 2-5/16" Trailer Coupler Lock part # 377DAT since it does not wraparound the entire coupler. I looked though our options and none of the wraparound styles will work with a 5" wide lip on the coupler.
    view full answer...
  • Can 4 or More of the Masterlock Coupler Lock # 377DAT be Keyed Alike
    Yes, if you select "keyed alike" from the drop down menu before you add 4 or more of the Master Lock Coupler locks part # 377DAT you'd get all of them keyed alike.
    view full answer...
  • Coupler Lock for RAM, Bulldog Style Gooseneck Couplers
    The Master Lock Trailer Coupler Lock # 377DAT is designed to fit trailer couplers that are towed with a rear hitch, not a gooseneck hitch. For a gooseneck coupler lock, you would want # BLTL-55-40D for RAM gooseneck couplers or # BLTL-50-40D for Bulldog/Stallion/Superior/T.E.M. couplers.
    view full answer...
  • Coupler Lock for a 2019 Jayco Jay Flight SLX 242BHS
    According to my research the Master Lock 1-7/8", 2", and 2-5/16" Trailer Coupler Lock # 377DAT will fit the coupler on your 2019 Jayco Jay Flight SLX 242BHS. I have attached a photo of this coupler lock on a trailer coupler that I believe is the same type that is on your Jay Flight. I have also attached a review video for you to check out.
    view full answer...
  • Coupler Lock Options for Haulmark 24 Foot Trailer
    There are three common trailer ball sizes, 1-7/8, 2 inch or 2-5/16 inch. Less common is the 50mm. The trailer ball size your trailer needs should be stamped into the metal of your coupler somewhere. A trailer coupler lock like the # DT25013KA from Fastway fits most standard, latch or trigger style couplers. Master Lock also offers some nice coupler locks like # 377DAT which fits all 3 sizes of trailer balls. Another option would be a lock like # e98886 that passes through the...
    view full answer...
  • What Coupler Types and Sizes Work with Master Lock Trailer Coupler Lock 377DAT
    It does not matter if your trailer coupler is an A-frame type of a straight channel type, you can use the Master Lock Trailer Coupler Lock # 377DAT on any size of either type so long as the coupler has a lip or flange around the ball cavity. The linked video shows how this installs on such couplers.
    view full answer...
  • Keyed Alike Coupler and Hitch Lock Recommendation
    The Master Lock 1-7/8" and 2" Trailer Coupler Lock # 377DAT can be keyed alike meaning that if you ordered several we could make sure that all of the ones you receive would use the same key. The Master Lock Hitch Receiver # 1481DAT does not have a keyed alike option. This product would ship with it's own key design. Based on what you are looking to do I think your best option would be the Master Lock Trailer Hitch Receiver Lock and Coupler Lock Set # 3794DAT. This comes with two coupler...
    view full answer...
  • Troubleshooting Trailer Coupler Lock by MasterLock Where Key Wont Turn
    You might try directing WD40 or a penetrating oil into the key slot and then working the key in and out a few times. It sounds like you have some sticky tumblers which the lube would help free up. Try that and let me know if it works.
    view full answer...
  • Coupler Lock Recommendation for Bulldog Collar Lok Coupler
    The Bulldog couplers are Collar Lok style which we have solutions for, but the MasterLock part # 377DAT is not the one you need. Instead the Fastway part # DT25013KA would be what you need.
    view full answer...
  • Can the Master Lock Trailer Coupler Lock # 377DAT be Rekeyed
    The Master Lock Coupler Lock, # 377DAT, is not rekeyable. Master Lock does not offer replacement lock cores for this particular lock. If you know the key number that was stamped on the original keys, you can order replacement keys using the Replacement Key for Master Lock Coupler Locks, # MLK1. If you do not have the original keys and the lock is stuck on your trailer, you can drill out the lock core to remove the lock, but you would need a new coupler lock to secure the trailer. If...
    view full answer...
  • Locking Pin for Brake Actuator Coupler
    You have a couple of good options. You can use our etrailer.com Coupler Lock, part # e98888, through the latching mechanism on the top of your coupler. This has a wide width so it will clear the sides. You could also use Master Lock 1-7/8" and 2" Trailer Coupler Lock, part # 377DAT, which attaches where the trailer hitch ball would go.
    view full answer...
  • Could a Master Lock 1-7/8" and 2" Trailer Coupler Lock # 377DAT Be Ground Off by a Grinder
    The Master Lock 1-7/8" and 2" Trailer Coupler Lock # 377DAT that you referenced is constructed of steel, which will make it harder to cut off then an aluminum coupler lock. But if a prepared thief had a battery powered grinder like you with a diamond cutting wheel it would only be a matter of time before he could grind the lock off. You have to consider that the odds of a thief having a grinder like this are pretty slim. Plus the fact that the amount of noise created by grinding on this...
    view full answer...
  • Will the Master Lock Trailer Coupler # 377DAT Fit a Goose Neck Trailer
    I have provided a link to the coupler locks that we currently carry that are compatible with gooseneck trailers. The Master Lock trailer coupler lock that you referenced is intended to be used on 1-7/8 and 2 inch trailer ball couplers. If your gooseneck trailer has a 2 inch ball this might work, but most likely it will not work. Additionally, the attachment style of this coupler lock may not be compatible with your gooseneck trailer coupler. Typically gooseneck trailers have a...
    view full answer...
  • Recommended Keyed Alike Trailer Coupler Locks For Multiple Trailer Application
    For your keyed alike trailer couplers, I recommend the Fastway Universal Trailer Coupler Lock for 1-7/8", 2" and 2-5/16" Couplers, # DT25013KA. This lock secures your coupler from the top and bottom. It is a noticeable theft deterant and it has a tube key lock cylinder to provide better security. It has an anti-drill pin and bolt blocked locking system prevents prying open the lock. Fastway has been shown to work on the most different styles of couplers. Other options for keyed alike...
    view full answer...
  • Tips for Unlocking a MasterLock Coupler Lock that Won't Release from a Trailer
    I would try hitting the locking mechanism with some WD-40 or a similar spray lubricant. Most likely if you get some lubricant on the portion of the lock that moves you will get it to brake free. If there is any tension on the trigger portion of the lock that could cause it to bind up and not release either. Also, make sure you have the position of the lock all the way in the unlock position so that it will release.
    view full answer...
  • Are all the Keys of the Master Lock Coupler Lock # 377DAT the Same
    Master Lock is a well-known lock brand that would not use the same key for every one of the Master Lock 1-7/8", 2", and 2-5/16" Trailer Coupler Locks # 377DAT. If they all had the same key we'd be able to offer you this with a "keyed alike" option meaning that if you ordered multiples we could make sure they all used same key. Since that's not possible that also indicates that the keys are unique and not all the same.
    view full answer...
  • Fit of Master Lock # 377DAT Coupler Lock on Cequent Performance Products Trailer Coupler
    If you're speaking of the Master Lock # 377DAT coupler lock, it should work fine with a standard trailer coupler such as part # F223000301. Cequent Performance Products is the parent company of Fulton and Reese. If your existing coupler looks like what's shown in the photo I provided, the # 377DAT lock should fit just fine.
    view full answer...
  • Trailer Coupler Surround Lock Option for Wallace Forge 20K Coupler
    I have a solution that may work for you, but after looking at photos of your coupler, the lack of a pronounced lip around the coupler means many of the style coupler locks you are looking for will not work correctly on your trailer. For a coupler lock that will secure inside the ball socket of the coupler, I really like the Master Lock Trailer Coupler Lock # 377DAT. My family uses this lock on our travel trailer to keep it secure. This lock has a large, flat plate to cover the bottom...
    view full answer...
  • Replacement Key for Master Lock Trailer Coupler Lock
    We do have replacement keys available for your Master Lock Trailer Coupler Lock # 377DAT with part # MLK1, however you will need to know the key number that you are needing. If you can find this number, you will simply enter it into the textbox below the product information for the correct replacement. If you cannot locate the key number, unfortunately there is no way to determine what key you will need for the lock. The Master Lock Coupler Locks are not rekeyable so your only option...
    view full answer...
  • What is the Master Lock 1-7/8 and 2 inch Trailer Coupler Lock Part # 377DAT Constructed Of
    The Master Lock Trailer Coupler Lock is constructed of steel that is plated to resist rust and corrosion and weighs about 4 pounds. The 2 black accents on the sides of the ball are plastic inserts but have no bearing on the sturdiness or locking ability of the lock. The shackle that secures the ball portion of the lock into the coupler is 1-1/2 inches wide by 7/8 inch thick and would be difficult to destroy or cut. We have a good selection of coupler locks and the best selling locks...
    view full answer...
  • Replacement Key Recommendation for Master Lock # 377DAT
    For the coupler lock part # 377DAT we have replacement keys as part # MLK1. You'll need to know the key number and enter it on the product page for the key.
    view full answer...
  • Installation and Operation of the MasterLock Coupler Lock # 377DAT
    To install this Master Lock Coupler Lock # 377DAT onto your coupler you will need to have your coupler in the unlocked position so that the ball portion of the lock can slide up in to the coupler. Once slid on you will push the shackle back and it is locked. It is perfectly normal that your coupler has to be put into the unlocked position before it will accept the # 377DAT. As long as you have a coupler that has is designed for a 1-7/8 inch or 2 inch ball and it has a lip around the...
    view full answer...
  • Is a Master Key Available for the Master Lock Trailer Coupler Lock # 377DAT
    The Master Lock Trailer Coupler Lock # 377DAT can be ordered keyed unique (like you are asking) but for one key to work for all of them you would have to get them keyed alike. The unfortunate side of this is that any key will work for any of them if that is the case.
    view full answer...
  • Will the Master Lock Trailer Coupler Lock # 377DAT Fit on a 2012 Keystone Cougar Trailer
    I did a little online research and found that Master Lock Trailer Coupler Lock, # 377DAT, should work well on the coupler on your 2012 Keystone Cougar X-Lite 30RLS trailer. I posted a photo of a coupler similar to the one I saw on the same model trailer as yours on the internet for you to check. Compare this coupler to yours so you can be sure this is the style coupler that is on your trailer. If so the # 377DAT coupler lock will work great.
    view full answer...
  • Availability of Keyed Alike Coupler Lock, Hitch Lock and Padlock
    Unfortunately, we can't get MasterLock products Like the # 377DAT keyed alike with different locks, but I might have an option to key everything else to your vehicle ignition key. BOLT offers hitch locks, coupler latch locks and padlocks that can be keyed alike to certain vehicle ignition keys. For instance, if you had a 2013 Chevy Silverado, you could use the BOLT # BL7018446 hitch lock, the # BL7018518 padlock or even the # BL5922987 locking tailgate handle. I don't have anything...
    view full answer...
  • Coupler Lock for a 2005 Texas Roll Back Trailer With a 2-5/16 inch Bulldog Coupler
    I did a little research and your trailer should have a 2-5/16 inch Bulldog coupler. With this style coupler the Master Lock 2-5/16 inch Trailer Coupler Lock, item # 377DAT, will not work. This style coupler lock requires that the trailer coupler has a lip around the front of the coupler. I recommend the Fastway Universal Trailer Coupler Lock for 1-7/8 inch, 2 inch and 2-5/16 inch Couplers, item # DT25013KA, which will work with almost any style of coupler and provides excellent security....
    view full answer...
  • Will Master Lock Coupler Lock for 1-7/8 and 2 Inch Couplers Fit a Hand Wheel Coupler
    I suppose that is true. There are many ways to defeat a lock. I found a couple more ways to do it while looking over couplers with hand wheels. A thief would have to have the right tools if they happened upon you trailer. Then they would need to take the time to remove the bolt, take out the lock, reassemble everything correctly so the trailer will still couple to a ball, and then hitch up to the trailer. Usually the mere presence of a lock is a deterrent; a would-be thief would move...
    view full answer...
  • Can Andersen Ultimate Fifth Wheel Connection AM3200 be Locked to Fifth Wheel Rails
    We have base rail locks like the part # TR63254 which will lock the Andersen Ultimate Connection part # AM3200 to the fifth wheel rails it's installed in. I attached an install video and a picture of this lock installed in a rail for you to check out as well.
    view full answer...
  • 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...




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Info for this part was:

Expert Research:
Mike L
Expert Research:
Michael H
Expert Research:
Jameson C
Expert Research:
John H
Expert Research:
Adam R
Expert Research:
Rachael H
Video Edited:
Jacob T
Updated by:
Laura H
Updated by:
Sarah W
Installed by:
Dustin K
Installed by:
Cole B
Video by:
Chris R

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