The transmission is one of the most complex parts of an automobile. For those who own vehicles with fourwheel drive or all-wheel drive, this complexity increases even further. All such vehicles contain an additional component known as the transfer case, which contains driveshafts that transfer power from the transmission to the front and rear axles.
Unfortunately, many people fail to understand the importance of their transfer case. As a result, the signs of transfer case problems often go unnoticed. If you would like to improve your knowledge of this vital transmission component in many automobiles, keep reading. This article outlines three frequent signs of transmission transfer case problems.
1. Trouble Shifting Gears
One of the most immediate and troubling signs of transfer case problems involves difficulty in shifting gears. You may notice a hesitation to engage with particular gears. In some cases, this trouble only manifests when travelling at certain speeds, and this issue may stem from a simple lack of lubrication.
In other cases, the issue has to do with a damaged or leaking transfer case output shaft seal. Like your transmission itself, the transfer case works by means of hydraulic power. In order to effectively translate hydraulic force into mechanical force, the transfer case must remain tightly sealed. The output shaft seal ensures that fluid remains inside of the transfer case.
Unfortunately, the output shaft seal has a tendency to develop leaks as years go on. A leak compromises your transfer case's ability to shift gears by preventing it from managing hydraulic pressure correctly. You can often verify seal problems by looking for fluid leaks beneath your vehicle. If a faulty output shaft seal lies at the heart of your poor shifting, an experienced mechanic must install a new seal to resolve the issue.
2. Unusual Grinding Sounds
The output shaft seal doesn't just keep fluid inside of your transfer case - it also acts as a seal for the sounds produced by the moving gears inside the transfer case. When a seal becomes damaged, these sounds often escape out, manifesting as an unusual grinding from underneath your vehicle.
These sounds tend to grow progressively worse as time goes on and the transfer case loses more and more hydraulic fluid. Hydraulic fluid, which is technically an oil, does more than just transfer force; it also ensures that all of the moving parts in your transfer case remain properly lubricated.
As transmission fluid escapes and overall fluid levels drop, your transfer case ends up without the lubrication it needs. This loss of lubricant increases metal-on-metal contact, thus increasing the volume of the sounds produced by the transfer case.
3. Erratic Four-Wheel Drive Performance
Four-wheel-drive systems fall into three categories: part-time, full-time, and active. Part-time and active four-wheel drives allow the transmission to operate in either two-wheel or four-wheel drive. With a part-time system, the driver manually makes the change between these two choices, while in an active drive, a computer automatically shifts to four-wheel drive at appropriate times.
Full-time systems, by contrast, operate in four-wheel drive capacity at all times. In other words, the front and rear axles both receive power any time your car runs. Part-time and active systems often make it easier to diagnose problems with your transfer case. Leaks and other forms of damage often result in an inability to remain in four-wheel drive.
In other words, your vehicle may shift in and out of four-wheel drive erratically, and seemingly without cause. If you have been experiencing this issue, your transfer case likely needs repairs.
For more information, please contact our experienced transmission experts at American & Foreign Transmission Service.