Thursday, May 15, 2014

Top 10 Signs of Transmission Trouble

Diagnosing car problems yourself may seem like an impossible task, but try to think of it in terms of your own body. For instance, if your stomach begins to hurt without warning, you'll probably start thinking of the last thing you ate in order to figure out why you're having the pain. A similar type of thinking goes into diagnosing car trouble. The moment you start noticing something out of the ordinary, it's time to start considering the problem and finding a way to fix it.

Mechanical auto problems, as opposed to electrical auto problems, are usually coupled with distinct sounds and sensations that are key indicators that something isn't functioning the way it was designed to. Transmissions take a lot of use over the years, and after a while, they're bound to start having some problems. Transmission repairs can be expensive, so it's worthwhile to pay attention to anything that seems unusual.

1.Refuses to Go Into Gear

One potential problem is that the transmission refuses to budge when you depress the clutch pedal and attempt to move the stick shifter.

It may happen when trying to get into first gear from a stop, or at any point up and down the assorted gears. Common causes include low transmission fluid, wrong viscosity (thickness) of fluid, or required adjusting of the shift cables or clutch linkage.

2.Burning Smell

If you get a whiff of burning transmission fluid, be advised it is definitely not the sweet smell of success. That's because it may indicate your transmission is overheating. Transmission fluid not only keeps the transmission's many moving parts properly lubricated, but it prevents the unit from burning itself up, by providing much-needed cooling.
In some vehicles, the transmission even has its own mini-radiator (an oil cooler) that circulates fluid to transport heat away from the transmission unit itself.
Common causes include low or inadequate transmission fluid, which can in turn indicate a leak or dirty fluid that needs changing.

3.Transmission Noisy in Neutral

It seems intuitive that if you hear weird noises when the car should be shifting, that the transmission is acting up. But would you suspect it if things were going "bump" in neutral? Yes, it could be the transmission.
Such sounds could have a simple and inexpensive solution -- as with many of the problems on our list, adding or replacing the transmission fluid sometimes does the trick. Bear in mind that as is the case with engine oil, different vehicles do best with the specific formulation called for in the owner's manual.

Alternatively, lots of noises from the transmission while it's in neutral could signal something more serious, like mechanical wear that will need the replacement of parts. In this case, common culprits are a worn reverse idler gear or worn bearings, possibly coupled with worn gear teeth.

4.Gears Slipping

In a normally functioning transmission, the car stays in the gear you designate, or that the computer designates for a given RPM range, until you or the computer initiate a gear shift.
But on a transmission in which the gears slip, the car can spontaneously pop out of the gear it's in while driving and (in a manual) force the stick back into neutral.This is unnerving at best and potentially dangerous at worst: when you mash the gas pedal to avoid an out-of-control vehicle, the last thing you want is a transmission that doesn't get power to the wheels. No need to scratch your head over whether this is trouble or not: if it happens, you know it's time to have your transmission examined.

5.Dragging Clutch

Here's another transmission trouble sign that haunts manual transmission vehicle owners: the dreaded dragging clutch. A dragging clutch is one that fails to disengage the clutch disk from the flywheel when the driver pushes in the clutch pedal.
When the driver attempts to shift gears, he or she can't because the still-engaged clutch is still spinning along with the engine. The driver is abruptly made aware of this by the grinding noise that then ensues with each attempt to shift.

Fortunately, the most common cause for this problem is not that severe or costly to fix -- at least not compared to some other transmission issues. More often than not, the problem is too much slack in the clutch pedal. With too much free play, the cable or linkage between the pedal and the clutch disk doesn't have enough leverage to disengage the clutch disk from the flywheel (or pressure plate).

6.Leaking Fluid

Leaking transmission fluid is probably one of the easiest ways to identify that your transmission needs attention. Automatic transmission fluid is vital to your car's shifting capabilities, so a little fluid on your driveway can quickly turn into a major problem. Automatic transmission fluid is bright red, clear and a little sweet-smelling when everything's working correctly.

                  Automatic transmission fluid should be bright red, clear and a little sweet-smelling.

When you check your automatic transmission fluid, make sure it's not a dark color and that it doesn't have a burnt smell. If it is, you'll need to take it to a mechanic and have it replaced. Unlike your car's motor oil, the transmission doesn't really consume or burn up any fluid during use, so if you notice you're running low on fluid, then it's definitely leaking out somewhere.

If you have a manual transmission, checking the fluid levels may not be as easy as simply lifting the hood and reading a dipstick. Manual transmission fluid has to be checked right at the transmission case -- usually through the fill plug.

7.Check Engine Light

The check engine light can be a great early indicator that something is starting to go wrong with your transmission. The check engine light can come on for any number of reasons not related to your transmission as well, but don't overlook this clear warning sign.

In newer cars there are sensors throughout the engine that pick up irregularities in the engine and notify the computer that there's something wrong in a particular area. In the case of transmissions, these sensors can pick up vibrations and early problems that you may not even be able to feel or see. If you want to know if your check engine light is telling you about a transmission problem, you can purchase a diagnostic scan tool that you plug into your car underneath the driver's side of the instrument panel. The scan tool will display a code that corresponds to the area of the vehicle causing the fault. If the code tells you there's a transmission problem, well, that's a good time to see your mechanic.

                                  Pay attention to your car's warning lights.

Car Dashboard Warning Lights - Understanding What They Mean 

Dash lights are nothing new, but the messages are. The following list of warning lights are the most common lights used by auto manufacturers. Not all warning lights are universal. Always refer to your owner's manual when you're not 100% sure what the light indicates.

Many warning lights indicate that a fault has occurred inside the vehicle's system, but it doesn't pinpoint the item or system that has failed. In these cases, a code reader or scan tool can help determine the part that needs to be replaced.

Here are some warning lights:

  • Check Engine or Malfunction Indicator Light (MIL):

Indicates the engine computer has set a Diagnostic Trouble Code (DTC). Usually requires diagnosis with a professional scan tool. 

  • Coolant Temp Warning:
Indicates temperature has exceeded normal limits. Check coolant level, fan operation, radiator cap, coolant leaks.

  • Oil Pressure Warning:
If this light stays lit, it indicates loss of oil pressure. Immediately check oil level and pressure.

  • Brake System
Indicates one of three possible conditions: parking brake is on; problem with the braking system/brake fluid is low, or ABS problem. Check brake fluid and make sure the parking brake is fully released. If the problem is in the ABS system, it may need a professional diagnosis.

  • ABS Light:
Indicates that the Anti-lock Brake computer has set a code and needs professional diagnosis.

  • Traction Control or ESP:
Illuminates when the vehicle's traction control/anti-skid or electronic stability system is in use. Usually an indicator that conditions are slippery.

  • ESP Fault
Indicates that there is a problem with the vehicle's traction control/anti-skid or electronic stability system.

8.Grinding or Shaking

Depending on whether you have a manual or automatic transmission, your car may respond differently when your transmission isn't working correctly. As noted in a previous section, with a manual transmission, a common sign of trouble is a grinding sound or feeling when you shift into a new gear. If you fully engage the clutch, shift and then hear a grinding sound, you may have a worn clutch or you may just need to have it adjusted.

Or perhaps one or more of your transmission's gear synchronizers, or synchros, is worn out or damaged. Grinding gears can be caused by a number of different factors.
For automatic transmissions problems, you'll most likely feel the car shimmy into each gear rather than the typical almost unnoticeable shifts, or the transmission will make a jarring transition into the next gear. Both are signs that your transmission needs attention.

9.Whining, Clunking and Humming

It's difficult to nail down exactly how your car may sound if there's transmission trouble, but one thing's pretty certain, you'll probably get a that-doesn't-sound-right feeling when you hear it. Every car is built differently, so the sounds they produce can vary greatly, but if you have an automatic transmission, there's a good chance you may hear a whining, humming or even a slight buzzing sound.

With manual transmissions, the sounds will usually come across as a bit more abrupt and mechanical sounding. If you shift gears and hear a clunking sound, then you definitely need to have it checked out by a professional.

10.Lack of Response

Transmissions are designed to go into the correct gear every time, so when they hesitate or refuse to go, it's a sure sign there's something wrong. With manual transmission problems, you may notice after shifting into a gear that the car's engine will rev up, but the car won't be moving as quickly as the engine is running. In this case, a worn-out clutch or more serious transmission problem may be occurring.

Automatic transmissions have the same lack-of-response problem, but will usually manifest the issue while engaging the "Park" or "Drive" selection. The car should shift quickly into either of these modes, but if your transmission hesitates to go into either one, then it's likely there's an issue with the transmission.

                             The Chevrolet Corvette is powered by this GL80 transmission

                        A graphic illustration of a Mercedes-Benz C-class sport coupe's 
                                               six-speed manual transmission

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