What Does Transfer Case Fluid Do?
You will only find a transfer case on all-wheel drive or 4 wheel drive vehicles. It is there to transfer power from the transmission to both of the axles. The main purpose of the fluid is to lubricate and cool, but in some models (for example Jeeps) it also takes on the role of a viscous coupling that can transfer power via the fluid.
Why Flush The Transfer Case Fluid?
It is not actually necessary to flush the transfer case fluid, rather it needs to be drained and refilled (kind of like an oil change). The transfer case holds only a minimum amount of fluid, so it is fairly inexpensive to refill. You should look at having a complete drain and refill about once wvery 80,000 miles.
The following warnign signs indicate a transfer case problem in your vehicle:
- If you notice a chatter noise on turns, caused by the rear wheel turning at a different speed than the front wheel.
- If you hear unusual noise on accelaration.
- If the vehicle simply will not move then it could be a complete transfer case failure.
Worst Case Scenario
If your vehicle’s transfer case fails completely then it will almost always need replaced rather than repaired. This runs to about $2000 for parts and labor.
Since the cost of a transfer fluid drain and refill is only around $60-$80, or $120 where synthetic fluid is needed, it makes sense to properly maintain the transfer case to avoid that worst case scenario.