If you have a 4x4 vehicle, that vehicle will have a transfer case. This key part operates much like a secondary transmission system. It works by transferring power from the transmission to the front and rear axles, and it's what allows you to switch to 4x4 mode.
Like many other parts of your vehicle, transfer cases require lubrication in order to work properly, and this lubrication is commonly referred to as transfer case fluid. You'll normally need to have yours replaced at set intervals, though regularly towing large loads or heading across challenging terrain can place added stress on the transfer case and result in the need for more frequent fluid replacements.
Taking care of those fluid replacements can improve the performance of your vehicle and prevent the need for repairs, so here are just four common signs your transfer fluid needs to be replaced.
1. Difficulty Shifting Into 4x4
You're probably not going to be driving in 4x4 mode all the time. Instead, you'll be switching in and out of 4x4 as circumstances demand. However, driving with either low or contaminated transfer case fluid can impact the system's ability to shift into 4x4 mode. Alternatively, you may find your vehicle is unexpectedly falling out of 4x4.
2. Loud Noises
Like many other common automotive issues, transfer case problems often make themselves known with unpleasant sounds. Since driving with low or contaminated transfer case fluid will result in improper lubrication, you may hear loud grinding sounds when you shift into 4x4 mode – in some cases, sounds will continue until 4x4 is disengaged. Such grinding sounds indicate metal-on-metal contact, so this is an issue to address as soon as possible.
3. Leaks Beneath Your Vehicle
Transfer case fluid may leak when your vehicle is at standstill, so you may be able to spot a puddle of it under your vehicle. The transfer case will usually be located towards the middle of your vehicle, just between the transmission and rear differential. This fluid will usually be red in colour, much like standard automatic transmission fluid.
Proper lubrication doesn't just prevent metal-on-metal contact – it also helps avoid overheating. As such, driving with low or contaminated transfer case fluid may cause the system to overheat, which can in turn damage parts such as the gaskets and bearings. If you notice a burning smell when you transfer into 4x4 mode, you may need new transfer case fluid.
For more information, contact a company like Alltrac 4WD.