Did you know that a properly working differential is the key to long-lasting car axles?
Differentials are the final buffers and transmitters of your car’s engine to the rotational movement of your vehicle’s wheels. Without a properly working differential, your car’s axles will bear the brunt of all the turning and change of direction.
If such is the case:
- How much does a rear differential seal replacement cost?
- How much does a front differential leak repair cost?
- How much does a differential replacement cost? What about a rebuild?
- What are the symptoms of malfunctioning differentials?
- When do we need to replace front or rear differentials rather than repair them?
- What are the possible ways to reduce the cost of differential replacements?
- How is the repair and replacement process of a differential done?
Differential Replacement and Repair General Costs
Differential repair and replacement usually cover at least one of the following:
- differential oil replacement
- differential parts replacement
- rear differential replacement
Pricing depends on the service that you acquire – which means the extent or the coverage of the repair or replacement, as well as the type of vehicle you wish to get repaired.
The differential oil replacement costs as low as $85 up to as high as $140 and can even be higher, depending on the lubricant used as well as the labor charges, taxes, and fees. It also varies from car to car. It is a short process that can be as quick as 30 minutes.
Differential parts replacement, on the other hand, depends on the part being replaced. It is the gasket, which costs around $130 to $190 and the differential output seal, which costs around $75 to $320 that often gets a replacement job. Although the price can be lower or higher, depending on the car model, the availability of the parts being used, as well as labor price, taxes, and other fees.
An overhaul, like an overall rebuild or a full differential replacement, costs even higher. Rebuilding a complete differential, for example, can cost around $700 to $1200, while replacing an old malfunctioning differential can cost at least $1,500. Additionally, replacement of the front differential is more costly than the back because the process requires the dismantling of the transaxle first.
Differential costs can be as low as $800 and as high as $6,000, and even higher, depending on the model and brand. These differentials, however, are already pre-assembled.
For internal parts, differential rebuild kits cost from $60 to $820, although there are rebuild kits that are vehicle and part-specific, which can cost as low as $20.
Here is a price range run-down of some differential parts and accessories you may wish to consider:
|Differential Part||Possible Minimum Cost||Possible Maximum Cost|
|Differential Gasket||$5.61 (general) , $5.65 (front)||$83 to $113|
|Differential Gasket Sealant||$2||$564|
|Rear Differential Seal||$12.78||$20|
|Differential Bearing-Seal Kit||$69||$662|
|Differential Oil||$5.31||$71 to $74|
Before you go to your nearest mechanic or auto repair shop, however, let us review a little bit about the differential and what possible things you can do to lower repair and replacement costs.
A differential is a device or a portion of your car that comprises of gears and pinions that transmit torque from your vehicle’s engine to the wheels.
The differential is located either at the front or the rear and is attached to the axle shafts that are connected to the car wheels. This allows your car to turn in different directions; granting the driver greater control of the vehicle.
Your car’s differential location depends on which wheels are to be controlled.
The front differential is used for front-wheel drives, while a rear differential is used for a back-wheel drive.
Full 4-wheel-drive vehicles, on the other hand, have both front and back differentials, while part-time 4-wheel drives do not have them at all which makes vehicles of this type difficult to turn.
A differential has three functions; the first of which is as a connector.
A differential is positioned in your car in such a way that it effectively completes the connection between the engine and the wheel axles. This allows your car’s differential to direct engine power to the wheels of your car.
Your car’s differential also shares the same function with the transmission which is to transmit force from the engine to your car’s wheels, but the difference becomes evident in 4WDs.
While there is only one transmission for every vehicle, your 4WD can have more than one differential. This is because the differential’s second function is to act as a final gear reduction – slowing down the transmission rotational speed before it hits the wheels.
The differential’s third task is what causes us drivers to have less difficulty in maneuvering our cars whenever we turn. When we drive, the wheels rotate at varying speeds – thanks to the presence of a differential. Without it, the inner wheel has to slip which makes this strenuous to the car axle and causes it to wear and tear faster.
Types of Differential
There are, as of the moment, about five types of automotive differentials – three of which are the most common. They vary in terms of how they react to quick maneuvering, rough roads, and turns.
The open differential, also known as OD, is the most common and present in many regular automobiles and thus, the least expensive. It performs the basic functions of a differential which is to let your car wheels rotate at different speeds.
This differential performs best on roads with good grip. But for slippery or icy terrains, it barely moves your car. And if it does, the car’s movement is time and energy-consuming (both for you and your car).
A locking differential, or locker, on the other hand, behaves like an OD on regular roads and can lock the wheels of the same axle together. This means that both wheels get power and the vehicle can run on rough and slippery roads like sand, mud, and ice.
The downside, however, is that if one wheel loses traction, the vehicle might slide off – a dangerous situation if one is riding up a slope especially one on a cliffside. Additionally, vehicles with lockers tend to have difficulty speeding on surfaces with good traction once the locks are switched on.
Between the OD and the locker is the limited-slip differential. The LSD works with a clutch pack – a thick high-performance differential fluid or a complex geartrain. This type of differential is often used by race cars.
The other two differentials – the electronically-controlled limited-slip differential and the torque-vectoring differential are also used in cars like BMW, Ferrari, Audi, and Lexus. They are more expensive, and in the case of torque-vectoring differentials, they tend to consume a lot of fuel.
Wear and Tear
A differential is built for durability and can last long enough as long as it is properly cared for – like by regularly changing the differential oil. This is usually done every 30,000 to 60,000 miles depending on environmental conditions, the severity of the job your vehicle does, as well as the type of oil used.
The best way to check when you need to replace your differential oil, however, would be to regularly look at the oil levels of your differential.
Regular oil change definitely helps a lot in prolonging your vehicle’s differential lifespan. But any vehicles will be subjected to eventual wear and tear, especially when we drive them roughly or over rough roads.
You can possibly have a malfunctioning differential if you either have:
- imprecise steering
- trouble making turns
- grinding or squeaking, especially near the tires which happens when you try to turn corners
- vibration throughout the vehicle or on the car floor
- squealing during acceleration
- a leak.
Take note that some cars give a humming sound rather than a squealing, wheezing or moaning noise. If this humming is left unchecked, it could turn into a growling which means that your car is in serious trouble and needs to be repaired the soonest.
So how does one know that the humming that your car has is a trouble call and not its regular tune?
A hum attributed to any problematic differential will remain constant regardless of the surface it runs on. A persistent hum – especially the one you have not heard before or any of the indicators mentioned above could mean that it’s time for you to contact a mechanic or an auto repair shop to have your car diagnosed as soon as possible.
Why Replace a Worn-out Differential?
With a worn out differential, chances are, your car is leaky, noisy or has maneuverability problems. When your car displays these symptoms, it is only a matter of time before you will have the ultimate trouble of not being able to drive your vehicle at all.
It is possible that your car still has a differential that is neither too worn out nor good as new but has some parts that need working on like a torn gasket, a worn output seal or sludgy oil which is actually good news since you need not change the entire differential itself.
Still, it is important to check the entire differential’s condition every time its parts are tinkered with. Note that a preventive differential repair and replacement means easier maneuverability and safer driving. It also means avoiding high expenses because of undue wear and tear on your tires as well as your axle components.
Repair, Replace, Rebuild
There are three possible scenarios when dealing with a faulty differential. The first two of which you can D-I-Y in your garage at your own pace. Here are the possible solutions to repairing a faulty differential:
- Worn Out Gasket and Output Seal
If either the gasket or the output seal of your car’s differential is problematic, the process requires removing these parts and replacing them.
The car is initially propped on jack stands and the wheels connected to the differential are removed. A drain pan is placed under the differential to remove the differential fluid and to check for any leak indicators, like debris, stones, and the like.
Removal and reinstallation of the gasket are followed using the car’s service manual. For a defective output seal, the CV axle is taken off first before the faulty output seal is uninstalled with a seal removal tool. Once this is done, the mechanic also checks the car differential condition since multiple scratches or problems on the gears inside will definitely mean a bigger repair or replacement job.
It must be noted that the replacements of either the faulty gasket or the worn out output seal have to be either the same model as the old ones or has to be according to the specifications of your vehicle. The mechanic has to ensure this before installing the replacements. Installation of the gasket will follow the vehicle’s manual while the putting up of a new output seal requires a seal installer.
The differential is then refilled with fluid and tested for any leaks before it is removed from the jacks. After this, the vehicle is test driven to further see any problems.
- Sludgy Differential Fluid
The car is first propped on jacks and the car is checked for a drain plug. If there is none, then the differential cover or gasket will have to be removed and replaced along with the differential oil for a small cost.
If there is a drain plug, it is first uncapped and the oil levels are checked, with the oil pan ready underneath it. The oil is then removed and checked for any indications of leaks or a faulty differential such as how sludgy the oil is or how much dirt and grime there is in the sludge.
Once the mechanic considers the murkiness normal, the differential is then refilled with new oil based on the amount, as well as the quality or type of oil the car needs. The differential is resealed and taken off the jacks, then taken out for a yard and road test drive as well as any leak check.
- Cracked Differential and Faulty Internal Parts
It is possible to have a serious differential problem in your car if you have:
- cracked differential
- improper contact between gears
- faulty universal joints between the transmission and the differential
- low power transmission to the wheel
Among the three cases of differential-related repairs, this is the one thing that you really cannot do unless you are a mechanic and have shop experience. Otherwise, it is better to leave the repair and replacement process to a recommended mechanic or an auto repair shop. Or better yet, a differential specialist shops like the following:
- Trail Transmission
- West Coast Differentials
- AZ Differential
- The Differential and Axle Shop
- Northampton Transmission.
The process of rebuilding, repairing, or replacing a differential takes hours compared to basic differential repair. The car has to be propped up and its wheels and other parts removed and diagnosed.
Does your car have a Front Engine Front Wheel Drive (FF Type)? If you do, it means your vehicle requires a higher cost and a longer process of replacing the differential because the transaxle has to be taken off first before the differential can be removed.
As a basic requirement, transmission fluid also has to be removed and checked for contamination and other sludge. New transmission fluid is also introduced during the replacement process of new parts and the reinstallation of the wheels which comes with a charge.
Once this has been completed, the car is then driven out for a yard to ensure there are no leaks or any further problems with the car.
Reducing Differential Replacement Cost
As mentioned above, differential replacement, compared to its oil change and seal output or gasket change, is not a task meant for your personal garage unless you are a mechanic and have a complete set of repair tools meant for the job.
Considering that differential replacement has to be left for auto repair shops as well as a differential specialist shop, there are two things that you can do – 1) get a quote from various mechanics and auto repair and differential specialty shops in your area and choose the service provider that best suit you, and 2) buy the parts yourself.
Another way to determine this is to ask for a definite service warranty. A mechanic or shop with a service warranty will definitely not want to do a faulty job. This is not only a toll on its track record; it is also costly.
When you ask around for quotes, also inquire for any specific car parts that need to be replaced in your car’s differential. In doing so you may be able to get an initial diagnosis and even some second opinion, as well as an idea of what possible differential parts you need to source out. This way, you can ask a follow-up question about whether the mechanic or shop is willing to service cars using the parts you personally bought.
If the service provider has their own differential parts, ensure that you already have your own “shopping list” with the specific brand and corresponding prices. There are some mechanics or auto repair shops that offer competitive prices for car parts because they have connections with car parts dealers that offer them lower bulk prices compared to standard market offers.
This is also another way of ensuring that you are getting roadworthy parts and not some chop shop remakes.