Basket Case: Three Common Symptoms Of A 4WD Transfer Case In Need Of Servicing

Posted on: 16 September 2016

The transfer case is one of the most important components of any 4 wheel drive vehicle, as it is responsible distributing power to all four wheels as and when it is requires. As you can imagine, this process requires a complex and durable piece of equipment to function properly, and the complicated mechanisms of a transfer box are prone to wearing out and malfunctioning over long periods of use. If your transfer box is starting to fail, you will probably notice one or more of the following symptoms, a clear sign that your transfer box is in need of thorough servicing.

Fluid leaks

Transfer cases are filled with special fluids that help to lubricate moving parts and increase heat dissipation, and fluid visibly leaking from your transfer case can be a clear sign of malfunctioning. In many cases, a leak can be caused by impact damage or simple wear and tear, which can be repaired and reinforced by mechanics relatively easily; however, leaks from the filler cap are more serious, as they can signify that the seal of the filler cap has perished or that the fluid is becoming too hot and boiling over.

Another clear sign of transfer box damage is fluid that spills from the filler cap even when the transfer case has not been overfilled -- this can signify that fluid from the transmission is leaking into your transfer case, a serious problem requiring immediate attention.

Difficulty shifting gears

This problem is noticeable in both automatic and manual 4WD vehicles and is generally characterised by sluggish gear changes, often accompanied by a groaning or grinding noise. This problem can signify excessive friction inside your transfer case and may occur as a result of insufficient, old or tainted transfer case fluid. However, transfer cases on older vehicles can suffer this problem even if kept fully lubricated, as the teeth of the metal gears within break down over time and stop locking correctly together.

Alternatively, difficulty shifting (especially when accompanied by strange noises) can signify problems with your transfer case's output shafts, which connect the transfer case to each axle. These shafts are sealed to protect them from outside damage, but these seals generally have a limited service life and can allow grit, road debris and other damaging particles to enter the shaft housing, causing excessive friction and wear. Make sure to have the shafts and their sealed housings fully inspected when your transfer case is serviced.

Shifting in and out of 4WD at random

This is a serious mechanical problem generally encountered in older 4WD vehicles, and requires immediate mechanical attention -- failure to do so can lead to loss of drive and acceleration control at high speeds, a particularly dangerous scenario.

Inability to maintain 4WD can be caused by a number of problems, including excessive gear wear (often caused by unnoticed fluid leaks), damaged or failed output shafts, or physical impact damage sustained to the transfer case while traversing uneven terrain. Sharp knocks taken to the transfer case while driving off-road are a common culprit here, as they can knock the output shafts out of alignment and impinge their ability to distribute power to both axles simultaneously.

For more information, contact a 4WD service in your area.