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  1. Trailer Tongue Lock
  2. AMPLock
  3. Fits 2-5/16 Inch Ball
  4. Surround Lock
  5. Keyed Unique
  6. Cast Iron
AMPLock Trailer Coupler Lock for Underslung 2-5/16" Ball Couplers - Ductile Cast Iron
AMPLock

AMPLock Trailer Coupler Lock for Underslung 2-5/16" Ball Couplers - Ductile Cast Iron

Part Number: AMP56FR
In Stock
$199.43
Trailer Tongue Lock
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Use this heavy-duty cast iron coupler lock to help prevent trailer towaway theft. Fits 2-5/16" underslung ball couplers. Resists picking, cutting, drilling, and freezing. Tumbler offers nearly 1 million possible key codes. Great Prices for the best trailer tongue lock from AMPLock. AMPLock Trailer Coupler Lock for Underslung 2-5/16" Ball Couplers - Ductile Cast Iron part number AMP56FR can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (95)
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AMPLock Trailer Tongue Lock - AMP56FR

  • Fits 2-5/16 Inch Ball
  • Surround Lock
  • AMPLock
  • Keyed Unique
  • Cast Iron
  • Universal Application Lock
  • Underslung Style

Use this heavy-duty cast iron coupler lock to help prevent trailer towaway theft. Fits 2-5/16" underslung ball couplers. Resists picking, cutting, drilling, and freezing. Tumbler offers nearly 1 million possible key codes.


Features:

  • Tamper-resistant, sturdy lock deters trailer theft by preventing hookup
    • Fits over coupler, engaging it like a trailer ball does and blocking the ball opening
    • Prevents would-be thieves from hitching your trailer to their tow vehicle
  • Push-and-lock cylinder locks without the need for a key
    • Lock's location on bottom makes it difficult for thieves to access
  • Rotating-disc-tumbler lock provides maximum security
    • Nearly a million possible key codes
    • Resistant to picking and drilling
  • Heavy-duty ductile cast iron construction
    • Absorbs shock to prevent breaking
    • Resists any kind of cutting, including cutting with a torch or liquid nitrogen
  • E-coat finish resists corrosion
  • 2 Keys included


Specs:

  • Application: underslung ball couplers for 2-5/16" balls
    • Maximum coupler width (including lip): 4-3/4"
    • Maximum lip thickness: 2-7/16"
  • Lock pin diameter: 7/8"
  • 5-Year limited warranty


Coupler Fits:

This lock fits underslung 2-5/16" ball couplers. An example of a coupler it fits is pictured below.


2516i coupler application

Secure Locking Mechanism

This coupler lock has a disc tumbler locking mechanism. Unlike locks that use vulnerable spring-loaded pins, this ultra-secure lock is bump-proof. The cylinder has a series of rotating discs that can be correctly lined up only when you turn the corresponding key. Two identical notched keys are included to operate the lock. Because these keys feature 1 of nearly a million possible key codes, it's extremely unlikely that another individual will have a key that can open this lock.



U-TLS-2516I AMP Lock Coupler Lock for Underslung 2-5/16" Ball Couplers - Ductile Cast Iron





Customer Satisfaction Score:


Customer Reviews

AMPLock Trailer Coupler Lock for Underslung 2-5/16" Ball Couplers - Ductile Cast Iron - AMP56FR

Average Customer Rating:  4.8 out of 5 stars   (95 Customer Reviews)

Use this heavy-duty cast iron coupler lock to help prevent trailer towaway theft. Fits 2-5/16" underslung ball couplers. Resists picking, cutting, drilling, and freezing. Tumbler offers nearly 1 million possible key codes.

by:

This is the best trailer tung lock I have ever used. Heavy duty, well built, with a very unique key system that was well thought out. YES, I would highly recommend the AMP LOCK SYSTEM FOR YOUR TRAILER. YOU WONT BE DISAPPOINTED.



by:

The lock is heavy duty and great. But it DID NOT work on my 2022 Jayco Micro. The lock mechanism needs to be about ?” shorter to clear the lower lip of the trailer hitch. e trailer wanted a 20% restocking fee plus for me to pay for shipping since I was outside my return window. The trailer was in for service so I could not test it out before the return policy ended. So I am either going to sell it or try to modify it myself.I would not buy it again for my 2022 Jayco.

Etrailer Expert

Heather A.

9/30/2022

This lock is for a underslung coupler. Most underslung couplers do not have a lower lip. If you could send me a photo of the coupler on your Jayco I am happy to assist you.



by:

Good tight fit, tough construction, and a disk core. It has sat out in the elements it's whole life and the lock still spins like new. I did drop the ball portion with the key still in it and it bent the key. That's my fault though. I Like the lock.



by:

Impressive lock. Well machined.
I was
disappointed I couldn’t engage ball with the hitch ball clamp assembly after the flange lock was installed.



by:

This is a nice lock, but there is plenty of room between the lip of the lock and the body of the trailer coupler for a prybar to be used. The coupler does have quite a bit of 'play' when installed - probably because it is a universal lock and as such it is designed to accommodate the dimensional differences between coupler manufacturers. Overall, the quality is very nice, and I have some ideas regarding how to 'tighten' up the fit between the lock and the coupler via shims. The manufacturer should consider including some shims - which could be used to provide a better fit between the lock body and the coupler.



by:

Trailer still where I parked it. This lock is doing its job.



by:

It is a little large for my 2", it fit my trailer with a 2 1/2" coupler, I wouldn't get another one.



by:

Kate was extremely professional and knowledgeable about the trailer coupler lock that I needed. She was very efficient and helpful in placing the order and when the lock arrived it fits perfectly. It is on my trailer right now and is exactly what I needed thanks to Kate and her performance. Give her a big monetary raise and recognition before her peers.



by:

Does its job as advertised. I leave this trailer on construction sites, and no attempted thefts yet.



by:

Heavy duty and very well made. No one's going to get it off!



by:

I have a car hauler with 2 inch receiver rolled lip. This coupler lock has what I wanted. It should prevent the opportunitistic thief from taking trailer.its a solid lock . I leave a trailer off-site so it's just added insurance. It will take some grinding to get off. Key is heavy and solid so shouldn't break in lock. Happy with purchase.



by:

I am impressed with the quality of the lock. The day we put it on in Buffalo, our sons bikes were stolen out of his garage. We were parked right in front of it. We were happy to have had it on.



by:

AMPLock coupler lock is fantastic. Used daily. Very well made, strong and def trust regularly to keep my trailer safe.



by:

Nice trailer lock, its expensive but if some one steals the boat it would be very in expensive then. :)



by:

Easy to use. Heavy duty. Seems very sec ure.



by:

Fit and finish are perfect Fits the Demco no lip 25K



by:

This lock is a solid and hefty piece of equipment. Make sure to get the right model for your set-up. The width of the lip on my trailer was 3.75” and the lock fits like a glove.



by:

the product is as advertised. expensive but much more heavy duty than any other I looked at before buying. the info on the website was helpful also.



by:

This AMP Lock Trailer Coupler Lock might be expensive but you get what you pay for here I believe. I have purchased 3 of these based on what I believe to be a quality product.



by: 03/07/2024

great lock



by:

I had a friend recommend this to me a year ago. Excellent lock for securing my car hauler! I recommend this to anyone that needs a trailer lock.



by:

Nice lock for my Air Stream Bambi, just what I needed, between this lock and my new wheel chuck locks from Etrailer.com it should not get stolen again. thanks Etrailer for my new lock setup.!



by:

Has worked flawlessly for over a year stored outdoors in Chicago. Finish seems to be holding up and the action still works smooth. This is a very robust design that would be difficult to defeat.



by:

Solid made, would be very very time consuming to overcome this lock , The lock cylinder is on the bottom, is harder to get to for locking and unlocking, That's ok is harder for thief to overcome it, This lock is well made and very heavy, Im glad to have this.



by:

Heavy duty item! It is a little looser when installed than I thought it would be but I understand it fits many different hitch types. Even though it does fit a little loose in my opinion, in no way would anyone be able to get it off!


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Info for this part was:

Employee Lindsey S
Written by:
Lindsey S
Employee Jameson C
Expert Research:
Jameson C
Employee Wilson B
Updated by:
Wilson B
Employee Michael B
Installed by:
Michael B

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