Differential vs Transfer Case

What’s the difference, and how do they work together?

A vehicle’s drivetrain is made up of many different components working together to transfer power from the engine to the wheels. Differentials and transfer cases both direct the flow of power to different areas of the vehicles. Cars and trucks have one differential if they are 2-wheel drive, two if they are 4-wheel drive, and 3 if they are all-wheel drive. 4-wheel drive vehicles are equipped with transfer cases. Both of these components are in the drive train, but what is the difference? 

What is a transfer case?

The transfer case is a mechanical component that receives power from a vehicle’s transmission. Transfer cases direct power via driveshafts to the differentials located in the front and back of a 4-wheel drive vehicle. Transfer cases have an interchangeable high and low gear range. Depending on the vehicle, transfer cases may incorporate a center differential.

married-transfer-case

Types of transfer cases

While all transfer cases accomplish the same goal, they come in different configurations. Some variants are better suited for heavy-duty or off-road use.

Chain driven transfer case

Chain-driven transfer cases utilize a chain within the case to transfer power to the front driveshaft. This type of transfer case is lighter weight and quieter. Light-duty trucks, jeeps, and SUVs use chain-driven transfer cases.

Gear-driven transfer case

Instead of using a chain to initiate a 4-wheel drive, gear-driven transfer cases utilize a set of gears to transfer power between the front and the rear. Gear-driven transfer cases come standard on larger trucks and are often used in place of a chain-driven transfer case on trucks, jeeps, and SUVs being used for off-roading. Gear-driven differentials are heavier and noisier, but stronger than those driven by chains.

Married 

A married transfer case bolts directly to the vehicle’s transmission.

Divorced 

A short driveshaft connects a divorced transfer case to the transmission.

What is a differential?

A differential is a case of gears that sits between the axles in the front or rear of a vehicle. Differentials divide the power from the engine between the axles, allowing each wheel to be driven. Full-time 4-wheel drive and all-wheel drive vehicles have a third, center differential, allowing the front and rear driveshafts to rotate at different speeds. Differentials allow the wheels to turn at different speeds, which is critical for safety and vehicle longevity.

wavetrac-differential

Ackerman Steering Geometry

Ackerman Steering Geometry uses steering linkages to keep all four wheels rotating around a single point. By rotating around a single point, the wheels of your car do not have to slide or skid while turning. While Ackerman steering solves this problem, the wheels must rotate at different speeds while turning.

Differentials allow the wheels to turn at different speeds while turning

When you are driving straight down the road, the wheels on your car are rotating, for the most part, at the same speed. However, when going around a corner or turning on to a different street, all four wheels rotate at different speeds. Without a differential allowing for different wheel speeds, turning can cause rapid and uneven wear on tires, poor handling, drivetrain binding, and potentially damage the drivetrain. A differential sends power to both wheels while allowing them to rotate at their own speed.

How do differentials and transfer cases work together?

All-wheel drive only uses differentials to move power through the drive train to the wheels. However, on part-time and full-time four-wheel-drive vehicles, transfer cases and differentials work together to increase off-road capabilities and drivability.

Part-time 4-wheel drive

A transfer case is utilized by part-time 4-wheel drive vehicles to switch between driving two wheels (normally the rear) and all four. Part-time 4-wheel drive vehicles can be switched between 2- and 4-wheel drive by the driver manually with a lever, or electronically via a switch. A part-time 4-wheel drive system incorporates a low gear range that can be used at slow speeds in off-roading conditions.

Part-time four-wheel drive does not use a center differential, meaning when the vehicle is in 4-wheel drive, all four wheels are rotating at the same speed. Part-time 4-wheel drive vehicles should not be driven at high speeds or on grippy surfaces light pavement when the transfer case is in 4-wheel drive mode.

Full-time 4-wheel drive

A vehicle equipped with a full-time 4-wheel drive does not run into the same issues as those with a part-time 4-wheel drive. In addition to a transfer case, full-time 4-wheel drive uses a third center differential in addition to ones in the front and rear. The center differential allows the front and rear driveshafts to rotate independently. The inclusion of this center differential allows vehicles with full-time 4-wheel drive to drive issue-free on the highway and at high speeds.

All-wheel drive

All-wheel-drive systems use three differentials and no transfer case. Vehicles with all when drive lacks the high and low range equipped on 4-wheel drive vehicles with a transfer case.

Get your differential and transfer case serviced

Differentials and transfer cases need regular servicing to function properly. The lubricating fluid inside needs to be becomes less effective. Schedule an appointment at Lake City Auto Care today and have our experienced technicians handle your differential and transfer case service!

What Does Excessive Exhaust Smoke Mean?

As your car runs, it produces emissions that are very poisonous to people and the environment. The exhaust system in your car prevents these gases from getting into the passenger area and improves fuel efficiency by monitoring the makeup of your vehicle’s emissions and calculating the correct air/fuel mixture based on the readings. You can monitor your car’s exhaust for changes that indicate engine trouble!

Take note of excessive exhaust color as it may indicate the problem within your car’s engine. These are the most common colors of exhaust and what they may mean for your vehicle.

Black Exhaust

If your car is producing thick, black exhaust it often indicates the burning of excess amounts of gas. This condition is usually caused by a faulty MAF sensor, which measures the amount of incoming air and calculates the proper amount of gasoline to mix with it to create a properly running engine. If it malfunctions it can cause your vehicle to run rich. A rich-running motor is getting to much fuel and not enough air. Not only will this lower your vehicle’s fuel economy, but it can also cause other engine problems, including burnt valves, a problem that may require expensive engine repair.

Blue Exhaust

 Oil burns blue. Blue exhaust is likely the result of an oil leak that is causing oil to enter the combustion chamber and burn off. Oil consumption indicates your car is not retaining the correct amount of oil it needs for proper lubrication. The final result will be an engine that is oil starved and may seize and quit working due to excessive metal on metal friction!

White Exhaust

White clouds of smoke coming out of the rear of your car often are a result of a coolant leak inside the engine. Coolant is entering the combustion chamber and burning up. A leaking head gasket is a frequent cause of an internal coolant leak. A coolant leak puts the vehicle at risk of overheating, which could lead to major engine damage. If the engine is getting too hot the block can crack, and pistons can warp. Before that sort of damage occurs, you’ll likely experience a plethora of other engine damage requiring extensive repair.

Exhaust smoke can indicate engine trouble. If you notice excessive amounts emitting from your vehicle, do yourself a favor come to Lake City Auto Care for engine diagnostics!

Lake City Auto Care is your one-stop-shop for auto repair in Hayden, CDA, and Rathdrum, Idaho. Our trained mechanics can handle any issue with your car, from the radiator to the exhaust pipe! Give us a call or schedule an appointment today!

Common Wheel Alignment Questions, Answered

Getting a wheel alignment is an important regular maintenance item on modern vehicles. A misaligned car can impact driving feel, gas mileage, safety and tire life.

What is a wheel alignment?

Wheel alignment ensures the wheels on your car are aligned parallel to one another. A wheel alignment is a procedure that adjusts the position of your vehicle’s wheels based on manufacturer recommendations. A properly aligned car will handle better, have more even tire wear, and get better gas mileage.

What is adjusted during wheel alignment?

Alignments use three different suspension angle adjustments to change the positioning of your vehicle’s wheels.

Camber:

The camber adjustment affects the outward and inward tilt of your wheels. Camber can have positive (top of the tire tilting out), negative (top of the tire tilting in), or neutral (tire sitting perfectly vertical) angle. Camber has a direct effect on the handling of your vehicle. Negative camber allows for better distribution of load while your car is going around a corner. This makes your car more stable. Too much negative camber will make the vehicle unstable in a straight line, as the sizes of the contact patches will be smaller.

Toe:

The toe adjustment impacts the steering sensitivity of your vehicle. Toe-in points the front of your tires in toward the center line of the car. Toe-out points them away from the center line. Toe-out improves steering response but reduces straight-line stability. When the toe is out of alignment in the rear, a positive or negative thrust angle will impact the way a vehicle tracks down the road, and can result in dog tracking.

Caster:

Caster changes the angle of the steering axis. The caster angle can be positive, negative, or neutral. A positive caster (steering axis leading the tire contact patch) allows the car to return to the center when the steering wheel is let go while turning and provides much greater stability than a negative caster angle.

Two-Wheel vs Four-Wheel Alignments

Depending on the layout of your vehicle, you will either need a two-wheel alignment or a four-wheel one. On larger trucks and SUVs that have solid rear axles, there is very little, if any, adjustment that can be made to the rear suspension. Vehicles with independent rear suspension will receive a four-wheel alignment. Independent rear suspension is more adjustable. Independent rear suspension can also come out of alignment.

What are the symptoms of a bad wheel alignment?

There are several distinct symptoms a driver will notice when their vehicle is out of alignment.

1.) Off-center steering wheel when the wheels are straight
2.) Car pulling to the left or right when going straight
3.) Uneven or irregular tire wear
4.) Dog tracking (the vehicle “crab walks” as a result of positive or negative thrust angle)
5.) Stability faults, typically a result of the ECU mistaking severe misalignment for traction issues.

The severity of symptoms depends on how misaligned your vehicle is. However, even if you don’t notice anything severe when you drive a mild misalignment will have negative effects on your tire life and fuel economy.

How often should I get an alignment?

At a minimum, your vehicle should go in for an alignment check once a year. The frequency can vary depending on your vehicle and driving style.

When do I need to get my wheels aligned?

Get an alignment check under any of the following circumstances:

  • After any minor front end collision
  • Hitting a large pothole
  • Running your wheels into a curb
  • Any suspension modifications (lowering or lifting your vehicle)
  • New tires are installed

Will a misalignment effect the tires on my car?

When your wheels are out of alignment, the tires will wear unevenly and shorten their life. Tires are expensive, and a proper alignment will ensure they last as long as possible. The way a tire wears can be indicative of what adjustment is out of alignment.

Camber Wear:

This type of irregular tire wear occurs when the camber adjustment is incorrect. Depending on the tilt of the camber, either the inside or outside edge of the tire will be significantly more worn than the middle.

Tire Feathering:

Feathering occurs when the toe angle is misaligned. Feathering presents as one side of the tread lobes smoothing, while the other side is sharp. The smooth and sharp sides will depend on the weather to toe is misaligned positive or negative.

How are wheel alignments done?

Vehicles have factory recommended alignment settings. Stock vehicles follow these recommendations. Adjustments to the camber and toe are most commonly made. Caster rarely falls out of alignment on newer vehicles.

Laser alignment machines utilize targets mounted on each wheel to measure the camber, toe, and caster angles. An alignment may be recommended based on the findings. The technician will then adjust the camber and toe, working rear to front. Once the machine shows the alignment angles are within the factory specifications, the alignment is complete. The technician will take the car for a test drive to ensure the symptoms of misalignment are gone.

Should my vehicle be aligned after suspension changes?

Lowered and lifted vehicles, or those oriented toward high performance and track driving will not always follow the factory recommended alignment angles. Like w said earlier, small changes to alignment angles can drastically affect vehicle handling. Some drivers want the increased cornering grip from a more aggressive negative camber angle. Others may want the improved steering response from an altered toe angle.

Get an Alignment

Schedule an appointment today and get your alignment checked at Lake City Auto Care! Our experienced technicians can quickly align your vehicle, eliminating misalignment symptoms, and improving handling. Lake City Auto Care provides quality auto care to the communities of Rathdrum, Hayden, and Coeur d’Alene.

Is Your Car Ready for Winter?

As fall moves into winter, make sure your vehicle is as prepared for the cold as you are. At Lake City Auto Care, we offer a winter prep check service to make sure your car reliably gets you where you need to go all winter long. Issues that create a minor inconvenience in the summer can be catastrophic and dangerous during the winter months. Read on to find out what systems in your vehicle need attention before the weather gets cold.

Antifreeze and Coolant

If the coolant in your vehicle is over 50% water when the temperature drops below freezing, both your cooling system and the engine can sustain catastrophic damage. Frozen water expands, and the cooling ports in your engine are not able to accommodate expansion. The result will be a cracked engine block and an expensive repair bill.

coolant-expansion-tank

Windshield Washer Fluid

In a blizzard on the highway not having windshield washer fluid can be extremely dangerous. Slush, mud, and snow kicked up from other vehicles can quickly reduce your visibility. When the road conditions are already bad, the last thing you need to worry about is a dirty windshield.

windshield-wipers

Battery Health

In the winter, being stranded in the cold by a dead battery can be serious. Ensuring your battery is healthy enough to start your car in the coldest temperatures is one of the most essential items to check before winter starts.

battery-jumper-cables

Oil Change

Starting your vehicle in the cold puts a lot of stress on the motor. Before the temperatures drop, it is important to have your oil and filter changed to ensure proper lubrication on cold starts. This winterization step will help extend the life of your vehicle by reducing the wear and tear on engine components on cold starts in the seconds before the oil has been disbursed throughout the block.

oil-on-dipstick

Tires

One of the biggest dangers in winter weather driving is lack of traction. Properly inflated snow tires will make your vehicle handle better, accelerate quicker, and brake faster on the slushiest and iciest roads. If you aren’t getting new tires, making sure the tires with the deepest tread are on the rear of the car will keep your vehicle in your lane when going around turns. Additionally, your spare tire should be checked for proper inflation and condition before the snow flies. Getting a flat in the cold without a functional spare can spell disaster.

tire-in-snow

Brakes

An inspection of your rotors, pads, and brake fluid before winter will ensure you can stop quickly and safely while driving on slippery roads. Worn pads are a safety issue on dry summer roads, and this issue is only amplified in the winter. If your pads are worn out or brake fluid is leaking, get your brakes serviced.

brake-disc-service

Let our technicians help

At Lake City Auto Care, we know the importance of properly winterizing your car or truck. Our technicians will look your vehicle over bumper to bumper and make sure you are prepared to safely drive in the worst winter weather conditions we see in Northern Idaho. Give us a call or schedule an appointment at one of our locations today!

6 Common Automotive Electrical Problems

Modern cars have a complex array of electrical systems responsible for everything from starting the engine to powering the radio. Electrical issues are common and have become harder and harder to diagnose as vehicles get more complicated. If you suspect your car or truck is having electrical problems, there are several common areas to check. These are the six most common automotive electrical issues.

Dead Battery or Bad Cables

If your car does not start, the very first thing to check is the battery. A dead or weak battery will be unable to power the starter, leaving you stranded. An easy way to check your battery is to turn on the headlights with the engine off. If the lights are dim or do not come on, your battery may be dead. Corroded or damaged battery cables can cause the same issues as a dead battery. A visual inspection of the terminals and wires can quickly rule this problem out.

dead_battery

Bad Alternator

The alternator converts energy from the engine into electricity to power the electrical components in your vehicle. The alternator is also responsible for keeping the battery charged. A failing alternator can cause issues with every electrical system in your car. You may notice the radio, headlights, or power windows not working correctly. A dead battery can also be an indicator of a failing alternator.

failing_alternator

Failing Starter 

The starter motor is responsible for cranking and starting the engine when you turn the key. If the starter motor has burned out your car will not turn over or start, you may hear a clicking noise when you turn the key, and in some cases, after prolonged attempts, the starter may smoke. A bad starter can be caused by bad wire connections, corrosion, or broken components in the starter motor itself. If you turn the key and the dash lights and headlights come on but the engine doesn’t start, the starter may be to blame. This test can rule out other electrical issues and isolate the problem to the starter motor.

Bad Ground 

The ground strap or wire is an essential component in your vehicle’s electrical system. The ground allows for excess electricity to safely escape from your car or return to its source in the event of a ground fault. A frayed or disconnected grounding wire in any of your vehicle’s electrical systems can cause a range of issues from no start conditions to dim and flickering lights. A bad ground can cause countless issues and is a good place to begin when diagnosing an electrical problem in your car.

Blown Fuse 

If you notice a single component like a tail light or your radio is not working, you may have blown a fuse. A fuse protects components in a circuit by stopping the flow of electricity when too much current passes through it. Fuses are found in a fuse box, which typically contains labeling indicating which fuse belongs to which system. Visual inspection of the fuse will tell you whether or not it is blown. Excessive current will cause the metal band in the fuse to melt, breaking the connection.

blown_fuse

Spark Plug Issues 

If the wires running to your coil packs or sparkplugs are damaged, dirty, or disconnected, the engine in your car will not be getting the spark it needs to run properly. A misfire like this can lead to other issues caused by unburnt fuel, like damage to the catalytic converters. You will also see a check engine light and experience poor performance if your spark plugs are not working.

coilpack_wire

Conclusion

Determining the cause of an electrical issue in your vehicle can be tricky. The system is interconnected, meaning one symptom can indicate a variety of different issues. At Lake City Auto Care, we take the guesswork out of solving electrical problems. Bring your vehicle to one of our three locations and we will diagnose and fix the issue, whether it’s a blown fuse or a faulty alternator. Give us a call or schedule an appointment today!