Sailboat, thanks. I wouldn’t have thought training would be an issue.
The Challenger tractors (shown in link) and others actually do move quite well on roads. They don’t travel quite as fast as wheeled tractors, which can travel in excess of 20 mph in road gear, but the track machines move right along…probably 15 mph or so. Unlike older track-laying machines which rode on a belt of linked metal plates, the new ones run on an endless belt of cleated rubber and don’t damage road surfaces.
SS
In theory. In practice performing a neutral steer can cause problems. You are OK if the surface is hard concrete. If you neutral steer on asphalt, the asphalt becomes gravel which may piss off whoever owns that asphalt. If you neutral steer on loose surface, its a good way to throw a track.
I wouldn’t characterioze it as a common problem, but it was a common concern, and track maintenance was no joking matter. A TC who threw a track had better have a good explanation ready to go because pointed questions will be asked by higher.
We threw track on an FTX at Hood, just driving at a moderate pace across open ground, and the BMO stopped by to chew us out. I, my TC, and our company XO respectfully disagreed with the BMO’s assessment of our maintenance deficiencies.
We (correctly, IMO, and the battalion XO later agreed) pointed out expected track life, current track life, the readily visible condition of my tank’s track, and the stack of 2404s going back many months with the red circle-X’s and the annotation “Deferred” endorsed by the BMO.
We didn’t so much as “throw track,” as it just sort of fell apart on us. :smack:
+1 QFT! The vast majority of thrown track that I saw was from neutral steers or pivot steers.
Is it possible to fix the track without lifting the tank? How is it done? How long does it take to fix or replace a track?
I can only speak to Abrams, of course.
If the track isn’t all the way off the road wheels (the center guides had come out of their groove between the road wheels, but the track is otherwise pretty much where it’s supposed to be), then sometimes it’s possible to “walk the track” back into place. This typically required firm ground.
If the track has come out of its usual position on the drive sprocket, you pretty much have to break track.
Breaking track! :cracks knuckles:
First, you hope that you’ve thrown track on relatively flat, firm, dry ground. :rolleyes:
Heh. Heheh. 
Yeeaah. 
Second, pick a section of track between the idler wheel and the #1 road wheel to break track.
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Next, you install a device called the track support chain. It is a cantilever-style chain-and-binder rig that you attach to the side of the hull (not the armored skirts, the bit behind them) between the Idler Wheel and the Sprocket (essentially, the length of the hull) and snug it down tight. As in, “That’s-going-to-kill-someone-if-it-snaps” tight. It’s purpose is to physically support the track once the track tension is released and the track is broken.
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Then, you back off the jam nut on the Compensating Idler Arm, and pop the relief valve. Grease will now spew out like Linda Blair puking pea soup, and the adjuster arm will contract, pulling the idler wheel with it, and tension will be released on the track.
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Now, you take out your track jacks (linear “pincer”-style screw jack) and your end connector puller, a hydraulic jack similar in concept to a gear puller, but configured to pull end connectors (item 3) off of the track ends (the metal rods sticking out of the track pad).
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Next, ensuring that your center guide (parts 6, 7, 8, & 9) is still firmly attached, remove the wedge bolts and wedges (4 & 5) from both the inside and outside end connectors. This will be problematic since the exposed threads sticking out end of the wedge will be destroyed. Imagine a horribly cross-threaded bolt and nut. Use 3/4" drive tools, a cheater pipe, and a strong, young, back. Sometimes it’s easier to just tighten the bolt until it breaks, and beat the wedge out with a sledge hammer.
7a) With the wedges and bolts removed, put the end connector puller (a ~30 pound hydraulic jack that you must hold in place until someone pumps the handle a couple of times to put some pressure on the end connector) on the outside end connector, and extract the end connector just far enough to get a track jack on. Install the track jack and make sure it has enough tension on it to hold the track together (being “pincer”-style, the jaws go over the track rods that the end connectors sit on and hold the track sections together). See this video. Wimps. :mad:
Have the lowest-ranking member of the crew repeat the process for the inside end connector. It’s what God made Privates for.
7b) Remove the center guide nut (9), tap the bolt (8) with a ball-peen hammer to knock it out, and the two center guide halves (6 & 7) should just fall out. Percussive persuasion [del]may[/del] will be required. Cussing doesn’t help, but it may make you feel better, and entertain your crewmates.
7c) Now the track jacks are holding the two track sections together. Using 3/4 drive ratchet and socket, slowly open the inner and outer jacks evenly until they are far enough apart that they essentially just fall off. Your track is now “broken,” and you’re ready for the next step.
7d) Warning: The U.S. Army has determined that the following is fucking insane, and only a lazy, dumb-assed tanker or congenital retard would ever attempt this.
7a-c take too damned long, and are a pain in the nuts.
Remove the center guide nut. Use your tanker bar (a 60" aligning bar) and a sledge hammer to knock your end connectors off. Stand a bit back and use same to smack the center guide very hard. Do NOT look at the center guide when you do this, as a face full of flying steel hurts. Helmets recommended.
7e) Your track is now apart. Have your driver back slowly until it falls off of the drive sprocket and is laid out flat on the ground. It is ready to be put back on; remove any bad section(s), install new/good section(s).
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Putting the track back on is pretty much the above in reverse, with the exception that to get the track back up onto the drive sprocket, you use a rope; tie one end to the first track link, and wrap the other end around the sprocket. Have the driver sloooooowly neutral steer away from whatever side you’re working on and the sprocket will winch the track back up onto it.
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Once the track section is firmly on the sprocket, remove the rope, and have the driver slowly drive forward. Be ready with the tanker bar to help it along over the Return Rollers and such, and it will go over the top of the Idler Wheel.
10a) Ideally, the two track sections will be long enough/close enough to slip the track jacks (now fully extended) over the track rods, and then begin tightening them up to bring the two track sections together close enough to get end connectors on (what the !@$#%& guys are doing in the youtube video, above)
10b) If not, stick the small end of the tanker bar in between two track sections about where it curves over the Idler Wheel, and have the biggest, heaviest guy hang off of it like Cheetah off of a tree branch. If that’s not enough, also have the driver sloooowly neutral steer to give you those few extra inches of track.
10c) Laugh your ass off when the tanker bar slips out and the big fat dude hanging on it falls flat on his ass, and smacks himself in the face with a 60" long, 15 pound chunk of hardened steel.
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If all else fails, back the track back off, take another hitch on your track support chain (see step 3), and try again.
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Break out the grease gun and tension the track by pumping grease into the Compensating Idler Arm. Don’t forget to do this, or you’ll drive about a quarter mile and throw track. Again.
That’s about what I remember of how to do it “The Army Way.” We came up with some shortcuts, circumstances permitting. See 7d.
New track comes palletized in 8-block sections. To put new track on, you have to back the old track off using the steps above, take it apart in 8-block sections, and pull it all out of the way. Pull new sections off of the pallets (an 8-block section weighs about 400 pounds; bring friends), line them up in front of the tank (and yes, you have to be pretty darned close in your alignment), connect them, and drive it on in the manner I described above.
Fixing one bad track block/section is a three-man job and on flat, firm, dry ground takes about 2-3 hours for a crew of average experience and motivation. Completely changing both sides of track on an Abrams (first one, then the other) is an all-day evolution for about 4-6 guys which is typically 2 crews, usually sans TCs. They have to stand back and fart, scratch, holler, look bored, and frequently check their watch in a meaningful manner, while saying things like, “In my day, we could change both side at once, in the snow, at night…” and so on in this manner.
ExTank, I read the dope because of people like you. Your first hand knowledge and willingness to share in a fun way is something unique in the age of wikipedia. Thanks for that!
I too can only congratulate ExTank on a most informative post. When I started the thread I had no idea I might actually gain an insight into what’s involved in changing the tracks on an M1 Abrams Tank, but it’s exactly the sort of thing I enjoy learning here. 
Always happy to provide some perspective
Just remember that there are also “fun quotient modifiers”, aka “Fuck You” modifiers, which enhance the track-changing experience.
Some FQMs include, but are not limited to:
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Mud. Deep mud. Soupy mud. Cold mud. That thick, clay-like mud that has its own gravitational effect on everything around it.
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Cold. For some reason, smacking your fingers with a hammer hurts twice as much when they’re practically frozen numb than when they are not.
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Heat. Add humidity for that final FQM Additional Misery Identifier. Sweat dripping off of you so much that you just about can’t see what you’re doing, or hold onto a tool even with leather gloves on.
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Insects. There’s nothing like a scorpion, tarantula, or centipede crawling down your shirt while you’re on the ground wrestling tools and/or track sections about.
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Tools. Lack thereof. As in, “Private Snuffy, where in the !@#$%& is the track support chain?! What do you mean, you took it off the tank and put it in the CONEX?!”
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Superiors. Standing over you and asking (not more than 5 minutes after the last time they asked) when the 2-hour job you’re doing will be done. They won’t do anything usefull like hand you tools, provide refreshing beverages, fetch food, or go AWAY!
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Weather. Separate from 1, 2, & 3, as few things enhance the track-changing experience like freezing rain, a dust storm, or a violent thunderstorm spewing hail and funnel clouds.