It is said that a vehicle and its driver are in constant communication whenever the engine is running — responding to commands on the part of the car, and paying attention to the reactiveness of the vehicle on the part of the driver.
As such, it is keen for a driver to pay attention to what the vehicle is communicating. The feel when handling the vehicle on the road and the sounds the vehicle produces are some of the most important indicators that a driver is required to take note of as they relay real-time information regarding the mechanical state of the vehicle. Others include notable defects, such as overheating engines and fuel inefficiencies.
And, at the core of driving is transmission. For any driver driving any vehicle, transmission constitutes a large part of the driving experience, more so for a manual transmission vehicle. It is the link between the engine and the wheels, dictating the power output that the vehicle rides on.
But, just what does transmission constitute in a vehicle?
Transmission, At a Glance
The gear stick/lever and the clutch/torque converter system are the components synonymous with transmission for most drivers. These components make up part of the drivetrain that feeds power to your vehicle’s wheels from the engine.
There are three types of transmissions that vehicles are equipped with. These are:
- Manual Transmission
- Automatic Transmission
- CVT Transmission
This is the oldest type of transmission used in vehicles, and also doubles up as the most engaging to drive.
The most distinctive features of a manual transmission vehicle are the gear stick and clutch pedal. The gear stick has, at most, eight gears, and the clutch disengages the powertrain.
With up to 10 gears, an automatic transmission is an upgrade on manual transmission, and the majority of vehicles manufactured today are equipped with this type of transmission.
Notably, an automatic transmission vehicle uses a fluid coupling, commonly known as a torque converter system, instead of a clutch like in a manual transmission vehicle.
The torque converter system provides several advantages over mechanical clutches in impulsive transmission, fast acceleration, cooling, smooth conversion, and fuel efficiency.
Continuously Variable Transmission (CVT)
A CVT is considered an upgrade on manual and auto transmissions, providing a blend of mechanical and automatic features.
The mechanical system may include pulleys, discs and rollers, or hydraulic motors. Instead of using gears, a CVT system has multiple shift points.
A CVT provides the most advantages of the three transmissions, especially in smoother operation and better fuel economy.
Maintenance and Repair in Manual and Automatic Vehicles
The mechanics employed in manual and automatic transmission systems vary. This means that there are aspects where one system has an advantage over the other — some of which we have already highlighted.
Like we mentioned, automatic transmission automobiles are superior in function compared to manual ones. However, they are also relatively more difficult to maintain, as we shall observe.
Hints of Defects in Transmission You Should Not Ignore, and What to Do If You Encounter Them
As with any mechanical item, your car’s transmission may encounter problems. If not immediately addressed, the trouble signs may escalate, causing you inconvenience and costly repairs, or worse, replacements.
Taking note of the trouble signs that relate to your vehicle, whether you drive a manual, automatic, or CVT, will help you act swiftly to resolve them, avoiding them becoming severe.
We’ve detailed below some of the possible transmission problems that might manifest in your vehicle and that you should be attentive to, as well as what actions to take in the event that you experience them.
This guide takes into account the unique problems that each type of transmission is likely to experience. This makes it beneficial particularly if you’re a new driver or are an already experienced driver that has swapped a manual ride for an automatic one, or vice versa.
1. Noisy Transmissions
Grinding, clunking, whining, or humming noises produced by your car’s transmission that are notably unusual should alert you to potential problems with your transmission unit.
For a manual transmission, these noises may be as a result of insufficient or contaminated oil, or a mechanical issue with the synchronizer or clutch that may need replacing.
If you drive an automatic and notice the seamless shifting of gears is no longer smooth, check your oil levels or have the drivetrain looked at by a professional.
2. Noise in Neutral
Low fluid or worn-down bearings, gear teeth, or reverse idle gear may cause your car to produce a bumping sound when in neutral gear.
You should check your fluid levels and pump them up if low. However, if the fluids are at an optimal level, the issue could be with the worn out parts we’ve highlighted and may require replacing.
3. Delayed Response When Shifting Gears
Whether you drive an automatic or a manual, if you notice an unusual hesitation in transmission whenever you shift gears, it signals an issue with your clutch, flywheel/flexplate, or connections in the transmission system.
You should treat this sign as urgent and have your transmission system checked at a repair shop as soon as possible. Failure to do so, and you may be staring at a defect that will become costlier to fix, as well as one that puts your safety on the road at risk.
4. Leaking Fluid
This is one of the easiest to notice. You can check for a fuel leak by inspecting the fluid levels, scent, and color using a dipstick, regularly checking the spot where you usually park your car, or putting in pieces of cardboard beneath the car and sliding them out.
If you notice a fluid leak, have your car assessed and repaired at a car repair shop.
5. Slipping Gears
The most hazardous of defects, slipping gears require immediate inspection of the drivetrain. You would want to avoid a scenario where your manual transmission gears are not in sync, or your automatic transmission inappropriately goes into neutral mode.
Slipping transmissions may arise from broken bands, low fluid levels, or use of different fluid additives in your transmission than the one you had been using.
6. Burning Smell
A burning smell is in no way characteristic. Therefore, immediately you detect a burning smell coming out of your engine, rush to inspect it.
A common cause of a burning engine is a contaminated fluid that fails to keep the engine warm, resulting in it overheating. Hence, you might be required to draw out the fluid and replace it with a cleaner one.
7. Transmission Light Comes On
The check engine light in your vehicle diagnoses a variety of problems with your car’s engine. Make sure that there is no problem with your transmission unit signaling the warning light on your dashboard.
An error code usually comes up on the dashboard, and you may want to familiarize yourself with a code/scan reader if you want to diagnose the problem yourself. However, the alternative would be to have your mechanic diagnose the issue with your powertrain.
Sam is Automole’s editor-in-chief and classic car enthusiast. Sam is studying mechanical engineering at Cockrell School of Engineering, Austin. He also writes for many top automotive publications and appears on the Collecting Cars Podcast.