What Happens When a Transfer Case Goes Bad?

The transfer case is found on vehicles with AWD or 4WD capability and is integral for allowing drivers to switch to these modes of operation.

A typical transfer case is found at the rear of the transmission and powered by the transmission output shaft, operating much like a secondary transmission unit.

Most 4WD transfer cases have four modes of operation:

  • two-high
  • neutral
  • four-low
  • four-high

Because the driver only engages the 4WD when needed, the system is what we call a “part-time” four-wheel drive.

But what happens when a transfer case goes bad?

What are the Symptoms of a Bad Transfer Case?

Transfer cases are supposed to last the longevity of the vehicle – however, that of course doesn’t always happen. Here we look at some of the more common signs you may find when you have a bad transfer case:

Shifting Issues

A common symptom of a bad transfer case is having trouble shifting between gear ranges. Although this issue could be caused by thing like a low fluid level or damaged linkage, it typically indicates an internal transfer case failure.

Before thinking the worst – first double-check the operating manual just in-case there’s something missed, such as being at a full stop and in neutral before shifting into 4WD.

Hard to stay in 4WD?

If you’re finding that your transfer case keeps popping out of 4WD, it could mean an external problem with either the differential or driveshaft – or it might be due to an internal transfer case concern. Best take it to a specialist for diagnosis.

4WD Won’t Engage or Disengage

There could be many reasons why a vehicle’s 4WD system won’t engage or disengage. From a faulty shift mechanism on the front axle, to an electrical fault in the control system. Yet it’s also possible the transfer case itself has internal problems.

Fluid Puddle Under the Transfer Case’s Location

There’s only one reason why there would be a fluid puddle right under the transfer case area – and that’s because there’s a leak somewhere. Check that the leak is likely coming from the transfer case by jacking up your vehicle and inspecting it. You should easily see the leak at the rear of the transmission or transaxle assembly.

Strange Grinding, Growling or Humming Noises

Another sign there’s a problem with your vehicle is the presence of unusual noises that weren’t there before. Weird noises can be bothersome, almost always indicating that bigger issues are right around the corner.

If you hear grinding, growling, or humming noises that change with your vehicle speed, it may be coming from the transfer case. This could indicate a low fluid level or some mechanical problem such as bad bearings, loose chains or damaged gears.

Possible Causes of a Bad Transfer Case

Commonly, a transfer case will fail due to a low fluid level caused by leaks, a lack of maintenance or regular wear and tear.

It’s important to address fluid leaks right away to prevent internal transfer case damage. Changing the transfer case fluid on a regular basis is also important. You can find the service interval for your vehicle’s transfer case in the owner’s manual.

It’s important to know that symptoms of transmission failure can mimic those of a bad transfer case. This can be confusing for vehicle owners who are attempting to fix their car themselves.

So why S&G?

To avoid any confusion, it’s always a good idea to get a professional diagnose of your vehicle if you suspect a transfer case problem. The specialist team at S&G Gearbox Exchange in Perth will be able to better assess your vehicle and its underlying issues and work efficiently to get your card back on the road. You can contact a team member here, or by calling (08) 9356 9988.