Driving a big rig up and down roads with steep grades can be stressful on its own, but when your low gear doesn’t engage, the situation only becomes more nerve-wracking. Not only does it pose a safety risk to you and your passengers, but it could signal a serious issue within your engine! To avoid overheating or causing further damage to your RV, here is what to do if your low gear doesn’t engage.
Whenever you're ascending or descending a steep slope in an RV, don’t devalue the importance of driving in a low gear. By overestimating the performance of your vehicle without this vital ability, you are putting your rig at risk. Overheating will likely stop you from making it to where you want to go anyways, so it’s better to play it safe and just pull off to the side of the road. Once you’ve located a safe place to pull over, apply your emergency parking brake before exiting the vehicle.
Examine Your Engine
When your low gear doesn’t engage, the most common cause likely has something to do with a transmission issue. If you’re like us, just the thought of having transmission problems can send shudders through your bank account, but the sooner you address the issue, the less money you’ll probably have to spend fixing it.
If you have an automatic transmission, the first thing you’ll want to check is the fluid. Transmission fluid is like the blood of the engine, without it all sorts of costly and damaging problems can arise. Before checking the fluid, consult with your owner’s manual to see if the engine of your vehicle should be running when you do so. Some manufacturers dictate that the engine should be warmed up, but turned off, so double-check your specific vehicle before pulling out the dipstick. If you don’t see a fluid level on your dipstick, you’ll know that you're low on transmission fluid.
Refilling your transmission fluid might seem like the end of your problems, but you’ll need to address the reason for why you lost your transmission fluid in the first place. The answer is likely a leak, which might be caused by an axle seal failure or an input shaft seal failure. Top off your transmission fluid (each vehicle manufacturer has a specific fluid, so be sure to use the right kind) before taking it into a mechanic for further inspection.
If your transmission fluid seems to be at an appropriate level, your gears may be worn down or broken. The problem could also be a broken shift linkage or throttle linkage, or damage to the electrical system, torque converter, or another component of the hardware. If you’ve recently changed your transmission fluid, the issues could also stem from putting in the wrong kind of fluid. Check with your mechanic who will be able to identify the exact problem and determine solutions.
With manual transmissions, leaks are less likely to be the problem. Most commonly, the issue has something to do with the clutch. You can try a stall test to determine if your clutch is slipping. To do so, put your vehicle in third gear and go as you normally would in first gear. If your clutch is working properly, the RV should stall. If your RV starts rolling or you smell a burning odor coming from your engine, you know your clutch is slipping. Your clutch might be worn down and may need to be replaced. Other causes of the issue could involve damage to your pressure plate or leaking gear oil. Take your rig to a mechanic for further examination and repair.
RVers are no strangers to the white-knuckle thrill of hauling a big rig, but without being able to engage in low gears, that thrill can quickly become panic. If you are preparing to trek up a hill in your RV and the low gear doesn’t engage, remain calm. Pull safely over to the side of the road and prepare to give your mechanic a call. As you examine your engine try to remember that these minor mishaps most often lead to memorable misadventures! Have you ever had problems with your low gear not engaging in your RV? If so, let us know about your experience in the comments below!