While working on my M41 “modernization” project (see my "What to build next" thread) I discovered a possible and super simple solution to the track tension issues HL Abrams tend to have with aftermarket metal/rubber padded tracks being too loose or way to tight. I had worked up a solution prior but it requires replacement every 3-4 hours of run time. This involve the use of rubber tape wrapped around the idler wheel to increase its diameter to ~ 41mm and thus cause an increase in track tension. The tape wears and pulls over time and as stated needs servicing which can take up to 40 min to complete.

What I discovered just the other day is that the M41’s idler is ~ 41.66mm in diameter and can reliably work with Abrams track. This was found during my experiment to convert the M41 to run Abrams tracks and sprockets. The light bulb turned on and if it Abrams parts worked on the M41 the M41 parts might work on the Abrams.

So I removed the M41 idlers and installed them on one of my Abrams. I had to use the M41 idler screws and three #8 washers on the back of each M41 idler wheel to line everything up. Once done and the track reinstall it was off to the test range. After an hour of hard fast turns, rocks, sand, reversing turns and yes jumps I had no issues with detracting. The tension with the M41 idlers is just about perfect, ok maybe not perfect, maybe just a little leaning toward the tight side but still dang good.

I will I’ll be running this conversion extensively over the weekend and see just how it holds up, but if the prior testing holds true the use of the M41 idlers on the Abrams could be the cheapest and easiest solution to the issue at hand.

For those worried about accuracy in details the idler wheel on the Abrams is 95% hidden from sight.

Below are a few photos of the this test conversion showing the M41 idler installed on the Abrams. These photos were taken after the initial hour long test run. Your questions and constructive input are welcome.

My friend did exactly this about a year and a half ago to solve his dklm tracks from throwing. I went to him with my detracking issue and hes the one that showed me the center flange sprocket that seems to have solved my issue of stock plastic tracks throwing.
His tank ran great after the m41 idler instal.

Wish he would have posted a write up on it, that would save a lot of folks (myself included) some major headaches. It is such a SIMPLE and CHEAP modification, but it is nowhere to be found on the internet, well at least not where I could find it. My DKLM tracks have proven next to indestructible, but like many other have found out can be a challenge to tune the tension. I ran this Abrams again this afternoon for another 30 minutes or so and had to really work HARD to throw a track. Even then it was simple to re-track and needed NO "hands on" help from me. So far this modification is working better than my original effort which in itself worked well. Before I call it "good to go" I still need to run it longer and on some different terrain types including mud.

One addition I will be adding to this modification is to slightly widen the space between the two idler wheel halves. The center track "teeth" on the Abrams track are wider than those of the M41 so there is little room for the Abrams teeth and debris to "share" especially in reverse while turning and chewing up dirt, sand, mud etc. This has not been a problem yet but I can see it being one that will show up at an inopertune time.

Just finished up another hour of running the Abrams with the M41 idler wheels. I ran the Abrams so hard that I broke three accessories off the turret basket from all the pounding and bouncing. Ran it with the top hull off for a full battery charge about 25 min and during this time was able to throw a track twice while doing hard turns in reverse which would lift and spill large amounts of dirt onto the idler wheels. I was surprised this only happened twice. With the hull on doing these same reversing hard turns there were no issues with loosing a track. The side skirts that cover the idler wheels help prevent this from happening.

The only other issue I had was not caused by the idler wheels but by larger dirt “clods” getting between the sprocket and track. But the issues they caused were related to the rear sprocket track retainer rings getting jammed up with dirt. Might have to see about only running one ring on each sprocket to combat this issue (sorry got of topic).

If tomorrow’s run goes as well as today then I will be a happy camper to final have the track tensioning issues behind me.

Update: 5/1/18

Ran this Abrams today for two full battery charges ( that’s about an hour ). No issues and am will call this modification good to go on this Abrams. I am going to ru it next on my other Abrams and see if the results are the same.