Hey everyone,
If you’re running a drilling rig, I don’t need to tell you how much time and money a little thing like track tension can throw off your whole operation. Last quarter alone, we had two regulars come to us panicking because their undercarriage tracks were either slapping so hard against their rig that they cracked side panels, or so loose they jumped off mid-job 100 miles from the nearest shop. That’s why today I’m breaking down exactly how to adjust track tension on a drilling rig undercarriage—straight from the guys who work on these things every single day, not some textbook jargon no one actually uses on site. Drilling Rig Undercarriage
First off, let’s cut to the chase: why track tension even matters. A lot of new operators think, “Tighter is better, right? Keeps the tracks on.” Nah, that’s a rookie mistake. Too tight, and you’re burning through undercarriage components like sprockets, rollers, and track pads way faster than you should. We’ve seen customers go through two sets of track pads in half the time because they cranked the tension down so hard the metal was shearing. Too loose, though, and you risk derailing—especially on uneven terrain like mud, rocks, or rough well pads. A derail at a drilling site? That’s 8+ hours of downtime, maybe more, waiting for a tech to come out with tools to get that track back on. Plus, loose tracks can throw off the whole rig’s alignment, making your draw works work harder than it needs to, killing fuel efficiency.
Our go-to sweet spot for most drilling rig undercarriages? 1.5 to 2 inches of sag in the track between the idler wheel and the middle roller, when the rig’s sitting on level ground and not loaded with drill pipe. Wait, hold on—let’s get that right: sag is the amount the track drops down from the top line between those two parts. If you measure less than that, it’s too tight; more than that, too loose. We’ve tested this a hundred times, and that range is the balance between no derail risk and minimal wear. But quick heads-up: that number can shift a little based on your rig’s make, the type of tracks you’re using (rubber vs. steel), and how much weight you’re carrying. We always tell customers to check their operator’s manual first, because some manufacturers specify 1 to 3 inches depending on the model.
Now, the step-by-step for adjusting this. Let’s make this simple, no fancy tools you don’t have on a typical service truck. First, prep the rig. You can’t do this adjustment when the rig’s sitting at a 10-degree slope or covered in mud—your measurements will be garbage. So park it on flat, solid ground, shut off the engine, set the emergency brake, and chock both front and back of the tracks you’re NOT working on first. Safety first, always. We’ve had a tech almost get run over because a track shifted while he was working—don’t be that guy.
Next, locate the grease fitting for the track tensioner. That’s the part you’ll be adding or removing grease from to tighten or loosen the track, right? For most undercarriages, it’s a big zerk fitting mounted on the idler wheel, usually with a big bolt or nut next to it that controls tension release. Wait, let’s split this into two parts: tightening (adding tension, if your sag is too big) and loosening (if it’s too tight).
If you need to tighten up (sag too much): Take your grease gun, make sure it’s loaded with the right grease—we always recommend heavy-duty, extreme-pressure grease for drilling rigs, not the cheap stuff you can get at the gas station. Connect the gun to that zerk fitting, and pump slowly. Don’t crank it the whole way—pump 2 or 3 times, then stop, wipe the fitting, and measure that sag again. Wait, a second after pumping, because the track settles into place. Keep doing this until you hit that 1.5 to 2 inch sweet spot. Once you’re there, make sure you lock the tensioner in place—most rigs have a lock bolt or nut on the idler side so the grease doesn’t push back out and loosen the track over time. Skipping that step is how you come back the next week to a derailed track.
If you need to loosen up (sag too small, track too tight): This one trips a lot of people up, because you can’t just yank the track loose. You have to release the pressure from the grease chamber. Locate the relief valve—usually a small bolt or plug next to that grease fitting. Grab a wrench, loosen that bolt a quarter turn (don’t take it all the way out, you’ll grease get everywhere), and let the excess grease and pressure bleed out. Again, do it slow—bleed a little, measure sag, bleed a little more, until you hit that range. Then tighten the relief valve back up, double-check the lock on the tensioner, and you’re good.
Wait, but hold on—there’s a pro tip we swear by that most guides don’t tell you. After you adjust tension, take the rig for a short test drive—like 50 to 100 yards over different terrain, then park it again and recheck the sag. Why? Because when you run the tracks, they settle, the grease shifts, and sometimes your initial measurement was off. We had a customer last month adjust tension in the shop, ran 2 miles down a dirt road, and the sag was way too tight—he’d have burned through tracks in a week. Test drives eliminate that surprise.
Also, when should you check tension? It’s not a set-it-and-forget-it thing. We tell our clients to do a tension check:
- After every 50 operating hours, especially after a job on rough, rocky terrain.
- After transporting the rig—vibration on the road shifts track tension all the time.
- If you hear that annoying slapping sound of the track hitting the rig frame—that’s your sign to stop and check, don’t wait for it to crack something.
- If you notice uneven track wear, or your fuel gauge is dropping faster than usual.
And let’s talk about common mistakes we see all the time. First, using the wrong grease. A lot of guys grab general-purpose grease, but drilling rigs work in extreme conditions—hot, cold, mud, dust. Cheap grease breaks down fast, so the tensioner can’t hold pressure, and your track loosens up. We supply our customers with the exact grease we recommend for their undercarriages, because we’ve seen what works. Second, rushing the adjustment. We get it, you’re on a tight job, but cutting corners here leads to way more downtime later. Third, ignoring wear. If your track pads, sprockets, or idler wheels are worn out, adjusting tension won’t fix the underlying problem—you’ll just have to do this every week. If your sag keeps going back to being too loose within a day or two, that’s a sign your undercarriage parts are shot, not that your adjustment was wrong.
Last thing we always emphasize: if you’re not comfortable doing this adjustment, don’t do it. A lot of operators try to save a few bucks by skipping the service tech, but one wrong move—over-pumping grease, not locking the tensioner, not chocking the tracks—can lead to a serious injury or expensive damage. We have a team of certified undercarriage techs who come on site to do tension adjustments, plus full inspections, so you don’t have to mess with it yourself.
At the end of the day, track tension isn’t some trivial maintenance task—it’s the difference between a smooth drilling operation and a week of lost production. If you run a drilling rig, you know every hour counts, and a well-adjusted undercarriage is one less thing going wrong on your job.
If you’re looking for high-quality drilling rig undercarriage parts, expert maintenance support, or just need help with tension adjustments for your current setup, hit us up. We work with rig operators across the board, from small well service crews to large drilling companies, and we’re here to keep your rig running strong.
Excavator Track Assembly References:
- Caterpillar Inc. Drilling Rig Undercarriage Maintenance Manual, 2022.
- Komatsu Ltd. Track Tension Best Practices for Off-Highway Drilling Equipment, 2021.
- International Construction and Mining Equipment Association (ICMEA) Undercarriage Care Guidelines, 2020.
Murphy Construction Machinery (Shandong) Co., Ltd.
Murphy Construction Machinery (Shandong) Co., Ltd. is one of the most professional drilling rig undercarriage manufacturers and suppliers in China, also supports customized service with low price. Please feel free to buy CE approved drilling rig undercarriage made in China here from our factory. For pricelist, contact us now.
Address: Room A3, Zone E, Yangqiao Industrial Park, Liuxing Street, High Tech Zone, Jining City, Shandong Province
E-mail: mefgcjx@126.com
WebSite: https://www.mefjx.com/
