I do tend to find obscure and interesting mods on tanks and armored vehicles when I'm bored.
So I grabbed these pics from a video showing this mod on the real Abrams. Of note the video maker is an active duty Abrams tank commander. He goes on to share that this mod is an interesting subject and there doesn't seem to be a rhyme or reason that some Abrams have them while others do not. He also explains that they are there for exactly the reason you'd expect to keep the tracks from skipping off and de-tracking altogether.
The track retaining rings were actually on the earlier version of the Abrams. I have seen them mounted on a few modern Abrams. I guess there are a few tank commanders that think they still have a benefit and knowing the Army there is probably a stockpile of them somewhere in a warehouse orderable through FedLog (ordering system for the military and government) with an NSN (National Stock Number) associated with them. I had an early Tamiya 1/35 M1 Abrams tank kit when I was a kid that had the retaining rings on the sprockets. When in the Army, I used to use the FedLog system to order components to fix the electronics equipment and computers I worked on. A single digit NSN mistake in FedLog could change a 1000ohm resistor into a locomotive or an Apache helicopter blade so you were always pretty careful about what you ordered. Pretty much everything had an NSN number.
AI response:
"The Abrams tank stopped using track retaining rings on the drive sprockets because debris like mud and rocks would build up, often bending or mangling the rings and causing the tracks to be thrown off more frequently. The original design of the early M1 Abrams tanks included a partial side skirt and a retaining ring on the drive sprocket, intended to help prevent the track from coming off during tight maneuvers.
However, in the field, this design proved counterproductive for several reasons:
Debris Build-up: Mud, dirt, and rocks would get caught between the sprocket and the retaining ring/skirt, packing tightly. This buildup put excessive strain on the system and could even shear the sprocket bolts.
Increased Track Throwing: Instead of keeping the track on, the mangled or clogged ring often became the direct cause of the track being thrown.
Maintenance Issues: When a jam occurred, the skirt and ring made it more difficult and time-consuming for the crew to access and fix the problem in a combat situation. Ultimately, the Army found that modifying the side skirt design to allow debris to eject more easily eliminated the need for the problematic retaining ring, leading to its official removal and discontinuation in later variants. "
Tank you, tankme (Derek): your explanation immediately above answers the question I had, but did not express. I imagined the tracks riding up on the outer diameter of the ring, putting so much tension on the tracks as to break the connectors or make it impossible for the crew to pull out a connecting pin.
Jib wrote: ↑Fri Nov 21, 2025 3:25 pm
I thought about having one fashioned for my 1/8 Abrams, as it (and my 1/16) often throw a track.
As tankme and the guy in the video I grapped those stills from said, the idea of those rings was to mitigate track tossing but also as they both mention the rings actually become a hinderence when combined with dirt, mud and stuff when turning and can also be a royal PITA for maintenance.
Jib wrote: ↑Fri Nov 21, 2025 3:25 pm
I thought about having one fashioned for my 1/8 Abrams, as it (and my 1/16) often throw a track.
Does your Abrams have a dynamic track tensioner (I.e., the return idler wheel is linked to the first road wheel). I had problems with my Tamiya Abrams keeping its tracks till I got a set.
No, neither one have that. No way to implement that on the 1/8, but I thought I remember seeing one for the 1/16 but it was out of stock and/or super expensive? But I can’t remember where.
Jib wrote: ↑Sat Nov 22, 2025 5:41 am
No, neither one have that. No way to implement that on the 1/8, but I thought I remember seeing one for the 1/16 but it was out of stock and/or super expensive? But I can’t remember where.
I did buy a active idler for one of my 1/16 Abrams, but never installed it. DKLM RC made one in limited quantities and someone else did also. The someone else is the one I bought (which is Cleong on RC Universe). Found the thread:
