Volvo All-Wheel-Drive Problems: Declassified

If you think you have all-wheel-drive problems, this page will tell you everything you need to know so that you can try to diagnose the problem yourself. We'll go over all the common signs, symptoms, and suggestions so that way you can keep the capabilities of your early model or new Volvo AWD up to par. Our master mechanic is about to explain everything, so get ready to feel like a pro in less than the five minutes it will take to read all this!

All-Wheel Drive (AWD) System Description & Operation

The majority of this article will cover AWD systems on the whole, so its application can accommodate the widest set of years and models. AWD is an evolutionary step forward from 4WD, though they are often mistaken for the same system. Have you ever wondered how your 4-wheel-drive or all-wheel-drive vehicle is able to shift weight so that your tires can gain traction? Here's the breakdown:

  • 4WD Systems - This is the original system that dates back more than 70 years and was developed to enhance traction in slippery conditions (mainly farming). Engine power is delivered to all four wheels via a mechanical component called a transfer case. The transfer case (sometimes referred to as the center differential) is behind the transmission and delivers constant power to both axles via mechanical action.

  • AWD Systems - Operate in a similar fashion, and while there are numerous AWD types, they all function similarly. Power is sent at a constant rate to the front (FWD) or rear (RWD) axles. When the system determines that enhanced traction is needed, the other axle is engaged. When conditions permit, the active axle is released and allowed to free-wheel again. The chief advantage for modern drivers is the fuel savings that come from AWD.

Always keep in mind that both systems are there to enhance your ability to make forward progress when conditions are at their worst. But how do you know the system is actually working? In the next section, we'll go over some of the common signs to be aware of that indicate your system is operating as designed. And in some cases, not!

All-Wheel-Drive Problems: Down & Dirty

Traction is achieved through 4WD, AWD, and other systems like traction control, hill-start-assist, drive mode selection, driver skill, and — simply put — tires. You can have the most sophisticated AWD system in the world, but if your tires are bald and you're in the mud, you're going to be there for a while. In other words, there's more to winning the battle for traction than having AWD or 4WD. Let's take a look at some questions, symptoms, and solutions commonly associated with all-wheel-drive problems:

What are bad transfer case symptoms?

The transfer case is a sophisticated piece of equipment that operates a complex matrix of gears, chains, shafts, sensors, and actuators. If you've got an all-wheel-drive system problem, this is likely the first place to look. If you think you've got a bad transfer case (or "t-case" or "t-box" in mechanic-speak), you'll definitely know. Here are the most common signs you may encounter when you have a bad transfer case:

  • You can hear a grinding at highway speeds
  • You have a transfer case over-temp warning on the dash
  • You might experience blinking lights in the drive selector area (model specific)
  • You might hear & feel a bang-bang-bang sensation under hard acceleration
  • Last but not least, you're getting stuck all the time when you know you shouldn't

How do I know if I have transfer case or transmission problems?

Great question! These components do separate things, though they work together to achieve the same result: getting you from A to B. The best way to determine this is with a factory scan tool. New Volvo vehicles have onboard computers for everything. If something is out of spec, we'll be able to hone in on it without having to guess.

That said, there are a few shade-tree things you can do to try to make this determination for yourself.

  • Start your car. Foot on the brake. Put her in reverse or drive. Did you feel the car take a gear? If not, you've likely got a transmission issue.
  • If your vehicle can drive, find some open road. Slow down quickly, then accelerate. Feel like you're in quicksand? Then that's a sign your transmission might be toast.
  • If your vehicle seems to drive ok, drive slowly at full circle left and full circle right. Do you hear an unusual grinding noise? That's your transfer case.
  • Find an open stretch of highway. At cruising speeds, do you hear a high-pitch howl? Let off the gas. Hear the pitch change under deceleration? That's also a signature transfer case fault.
  • Not sure? Come see me!

My all-wheel drive is not working. Now what?

There are some instances where a minimal repair might get you going again. Sensors, actuators, and solenoids can fail and be replaced. If that's the case, your warranty coverage may cover a portion or all of the repair. If it isn't one of these simpler solutions, then you are likely looking at a rebuild or replacement of your current transfer case.

Volvo XC90 all-wheel-drive problems. Fact or fiction?

Many people call in asking about all-wheel-drive problems related to the Volvo XC90. While all-wheel-drive problems are common across all makes and models, the Volvo XC90 transfer case tends to fail because of a prior fluid leak, mileage, or improper service. Like any other vehicle, diligent service is required for long-term reliability. When service is "deferred," it's only a matter of time until a component fails.

What are the disadvantages of all-wheel drive?

4WD enthusiasts will tell you that AWD is the less reliable of the two systems. That argument rests on the fact that true 4WD is mechanical and usually permanent — therefore more reliable. AWD tries to create fuel economy by relieving engine load from one of the live axles. AWD is largely dependent on many support components to do this, and from that point on, it's all down to the law of probabilities. The truth of the matter is that either system is equally susceptible to failure depending on your driving style and maintenance commitments.

Frequently Asked Questions

How to tell if your AWD is working?

Generally, you will be able to feel a change in the way your vehicle drives if the all-wheel drive system stops working correctly. There are other ways to check, however. You can have a friend observe the wheels of your car while you slowly begin to drive; they should be able to tell if all four wheels are receiving power or not.

How to tell if your Volvo XC90 is all-wheel drive?

You can check the documentation that your vehicle came with to see if it is an all-wheel drive version of the car. Your other option is to find out for yourself. To do so, have a loved one or a friend observe your vehicle's wheels as you slowly move forward. If they see all of the wheels turning in concert, your Volvo XC90 has all-wheel drive.

What does "Service AWD System" mean?

If you see this message on your Volvo vehicle, you'd be well-served to make an automotive service appointment as soon as possible. Problems with your all-wheel drive system can be serious and should not be left unattended. Managing the powertrain of a vehicle is complex work. If you are not a trained technician, you'd be better off leaving this job to a professional.

Thanks, Mr. Mechanic. But Why is My All-Wheel Drive Not Working?!

It's frustrating when something doesn't work. When computers won't load. When garbage disposals fail. When smartphones have issues. When Bluetooth headsets lose a connection right in the middle of a call. While never convenient, mechanical failure of any kind, even all-wheel-drive problems, need to be taken with a grain of salt.

Here's the golden rule: if it's made by the human hand, it will fail. And if it fails, it's the human hand that can also fix the problem.

That's why Bill Kidd's Volvo Cars is here. We're your pit crew that's always on hand to take care of any issues that come up, so you can get back out there in your day-to-day race. Interested in unlimited peace of mind? Check out a Certified Pre-owned Volvo vehicle with unlimited miles on your powertrain.

We hope you enjoyed reading our information page on all-wheel-drive problems, and we'd love it if you shared it with others that might be interested in it too. Love this article? Contact us and let us know!

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