There’s nothing quite like transmission problems to stress out the average car owner. They are, at best, inconvenient and, at worst, very expensive. Proper vehicle maintenance is the best way to prevent transmission issues, but realistically, if you own your vehicle long enough, or if you’ve bought an older vehicle, sooner or later your car will develop some type of transmission trouble.
Transmission problems, if not fixed, will inevitably become worse, and there are some early indications that you should have a mechanic check out your vehicle. The following can be signs of a bad transmission:
Check Engine Light comes on: Your Check Engine Light is the first indication that something has gone wrong, or is about to. It can mean any number of things, including transmission problems. There are sensors throughout your vehicle that tell the on-board computer if anything unusual is happening, and a number of those sensors are located on your transmission. They can pick up the tiniest vibration or jerk that you might not even feel. Never assume that your Check Engine light has come on for no reason.
Clunking, humming, or whining: Transmission noises can be hard to identify, but they usually sound like whining, humming, buzzing or clunking. If you hear something that you’ve never heard before, it’s always best to get it checked out.
Shaking or grinding: Your car shouldn’t shake or jerk, and you shouldn’t hear grinding. These are all indications of transmission trouble. With a manual transmission, the most common red flag is grinding when you shift. If it happens after you engage the clutch and shift, it could also be a sign of a faulty clutch. Either way, you need to get it checked. With an automatic transmission, you’re more likely to find it’s hard to get into gear when you first take off. As it worsens, you’ll notice shaking. Again, get it checked.
Noise in neutral: If you notice a bumping sound when your car is in neutral, the problem could be as simple as low or dirty transmission fluid. If topping up the fluid doesn’t help, the fluid could be dirty, or there could be worn parts in the transmission – usually the bearings, reverse idler gear, or gear teeth.
Hesitation: If the car hesitates when shifting, it’s usually a problem with the clutch. But if you find that the vehicle isn’t shifting smoothly, it could also be a sign of transmission trouble.
Low or leaking fluid: A transmission fluid leak is one of the most reliable signs of a transmission problem, and should never be neglected. If you allow it to continue to leak, you could cause irreparable damage to your transmission. You can identify leaking transmission fluid easily. It’s bright red, and clear, and smells a bit sweet if everything is working properly. If the fluid looks dark or has a burnt smell, then your mechanic can drain it and replace it with new transmission fluid.
Car won’t go into gear: This could also be a fluid problem, so check it and make sure that it’s at the proper level. It could also be a problem with the clutch linkage, the shift cables, or the computer system.
Burning smell: Obviously, if you smell something burning, you should act immediately. Eliminate the possibility of fire, and then consider other causes. One of the most common causes of a burning smell is car transmission fluid that’s overheating. This happens when the fluid breaks down due to debris and sludge. Dirty fluid isn’t going to keep your transmission parts cooled and lubricated so that they don’t become damaged, and if you allow your car to run with dirty fluid, you’re eventually going to end up with a bad transmission.
Draggy clutch: If you have a manual transmission, and the clutch seems to be dragging, it’s because the clutch disc and the flywheel aren’t disengaging when you press the clutch pedal. The clutch is still spinning, and changing gears will be difficult, if not impossible. You’ll probably find that this problem is accompanied by a grinding sound when you try to switch gears.
Slipping gears: Your transmission is supposed to stay in one gear until you shift (with a manual transmission) or the computer does it for you (with an automatic transmission). If the transmission is slipping in or out of gear without any effort on your part in a manual, or sliding into neutral in an automatic, you need to get to a mechanic immediately! This is a huge safety issue, because if you need to hit the gas to avoid a dangerous situation, and you have no power to your wheels, the results could be catastrophic. The problem is likely worn or broken gear linkage, so if this happens, don’t waste time – get it fixed. Of all the transmission problems we’ve talked about, most of them won’t get you killed except for this one.
This article originally appeared on YourMechanic.com as The 10 Transmission Problems to Never Ignore and was authored by Valerie Johnston.