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How Often Should Auto Transmission Fluid be changed?

How Often Should I Change Transmission Fluid?

well, um, ahh huh,  well  let’s see… How often to change transmission fluid depends on several factors Sonny outlines in this post.

_by Sunny Pruitt|June 21, 2022

Motorists sometimes ask, “How often should I change transmission fluid?” It depends on your vehicle and driving habits. Recommended transmission fluid changes run the gamut from every 30,000 miles (48,000 km) to never. Yeah, that’s right. Here are some tips for determining how often to change transmission fluid.

Change Transmission Fluid: How Often? Check Your Owner’s Manual

Original equipment manufacturer (OEM) recommendations for how often to change automatic transmission fluid cover a wide mileage range, depending on year, make and model.

Plus, if your driving habits are like most motorists and fall under the “severe” designation (towing, hauling, daily short trips less than 10 miles, etc.), many OEMs recommend changing transmission fluid more frequently.

Here are just a few examples to illustrate the disparity among vehicle makes and models.

Year/Make/Model Normal Service Severe Service
2021 RAM* 1500 Never (filled-for-life transmission) Change if the fluid becomes “contaminated”
2021 Chevy* Silverado* Never (filled-for-life transmission) Every 45,000 miles (72,000 km)
2021 Ford* F-150 150,000 miles (240,000 km) 150,000 miles (240,000 km)
2003 Honda* CR-V* 90,000 miles (145,000 km) 30,000 miles (48,000 km)

These differences illustrate the importance of checking the recommendations in your owner’s manual. It’ll provide maintenance recommendations, typically in a table in the back. Many OEMs provide digital owner’s manuals online, so if you’ve lost yours, try a quick search.

A quick word on “filled-for-life” transmissions.

They’re becoming more prevalent as OEMs seek ways to alleviate motorists from unwanted maintenance. They sound like all upside, but it’s important to change fluid in these units, particularly if you tow or haul.

They’re supposed to last the life of the vehicle, but what do you suppose will happen if the transmission fails once the warranty expires? You’re going to get stuck with a hefty repair bill, that’s what. Be proactive and change fluid at least once during its lifetime.

Change Transmission Fluid: How Often? Go By The Book

Start with the recommendations in your owner’s manual.

But, how many of us dutifully follow them down to the mile? But as you know most drivers completely forget about their transmission until it begins to shift hard, jerk hard jerk hesitate. Out of sight, out of mind, right?

Not good, especially if you tow or haul. But the interval does depend on the abuse and the quality of the fluid.

Heat Kills Transmissions

Over time, transmission fluid oxidizes (chemically breaks down). High heat generated from towing and hauling speeds the process.

Fluid that has broken down can cause sludge and varnish to form, which clogs narrow oil passages and contributes to clutch glazing. Soon, your vehicle can begin to shift poorly.

In these cases, wouldn’t it be great to use a transmission fluid formulated with reserve protection against heat in case life gets in the way of recommended maintenance?

Get Reserve Heat Protection For Your Transmission

AMSOIL Signature Series Synthetic Automatic Transmission Fluid’s built-in reserve protection means it lasts for 2X the OEM’s severe-service drain interval. That means you can rest assured your transmission is protected, even if service is delayed.

Symptoms Of Low Transmission Fluid

It’s not just heat that leads to poor shifting. Low transmission fluid can also present a number of problems, including…

  • Inconsistent, jerky shifts
  • Hesitation
  • Surging
  • Increased transmission temperatures

Low Transmission Fluid = Poor Shifting

Transmission fluid serves a number of vital functions, one of which is to act as a hydraulic fluid to enable shifting.

When your vehicle’s computer tells the transmission to change gears, hydraulic pressure (provided by the fluid) squeezes a series of plates together inside a clutch pack to connect the engine to the transmission output shaft and route power to the wheels.

Low transmission fluid can also prevent the torque converter from filling completely, which reduces torque transfer and causes hesitation and lost power. In extreme cases, the vehicle won’t even move unless you rev up the engine.

How Much Transmission Fluid Do I Need?

How much transmission fluid your vehicle needs ranges from as few as 8-9 quarts for small passenger vehicles to more than 20 quarts for heavy-duty trucks.

As you do when determining how often to change transmission fluid, check your owner’s manual for the transmission fluid capacity.

You can also check the AMSOIL Product Guide, which shows how much transmission fluid your car needs for most makes and models.

Also do you know if you need to use a flushing agent? Amsoil engine and transmission flush is a mild detergent flush but it’s used when you are going to evacuate all the fluid. Restores friction capabilities of the clutched. Best before adjusting the trans when you have over 160,000 miles.

Low Transmission Fluid Can Invite Wear

Transmission fluid also lubricates the gears, clutch plates and seals. It forms a protective layer between meshing gear teeth that prevents metal-to-metal contact and helps reduce wear.

It helps prevent wear on the clutch plates, which bear significant friction during gear shifts. The fluid also lubricates seals and keeps them pliable so they don’t dry out and leak. Find out all the tasks transmission fluid must perform here.

Low fluid can prevent formation of a strong, consistent lubricating film on components, inviting wear. Foam bubbles can collapse when they pass between gear teeth, allowing metal-to-metal contact and further accelerating wear.

Always Check Your Transmission Fluid – Look at the color too

To keep your vehicle running – and shifting – at peak performance, check the fluid about once a month to ensure the correct level. Check out this post on how to check your transmission fluid. If the fluid is consistently low, visit a mechanic to find out why and have the problem fixed.

So, when determining how often to change transmission fluid, follow the recommendations in your owner’s manual. For added peace of mind in case you surpass those recommendations, you can rely on AMSOIL synthetic transmission fluid to deliver reserve protection. Do you know if it has to be warmed up and running?


Texas Heat Proof AMSOIL Gives Transmissions a Break

AMSOIL Synthetic Transmission Fluid Tames Texas Heat

Not even a “spot” of sludge in the pan or on the filter despite extreme heat & heavy towing.

BTB Services owner Bryan Bayles and employee Oscar DeLeon stand by the company’s 2015 Chevy 2500, which is still running strong thanks to good maintenance and AMSOIL products.

by John Baker | December 2022

Customer Bryan Bayles, out of Katy, Texas, saw a need while working as a groundwater sampler and turned it into a successful business. “We used to go to these sites that were really hard to get to because they weren’t being maintained,” he said.

Neglect and disuse often turned groundwater sampling sites into jungles of overgrown weeds and brush, sometimes teeming with rats. Today, Bayles’ company, BTB Services, does what’s called “post-closure care.” His crew maintains groundwater-testing sites around refineries and other sites so they remain accessible.

“One site was 25 acres and in the middle of a town,” said Bayles. “People started complaining about rats running out of it.”

Much of the work involves using tractors, zero-turn mowers and handheld equipment to cut large areas of grass and brush.

“We take tractors out and weed eaters to get the paths clear so we can get out there,” Bayles said.

BTB Services operates three large mowing tractors, two zero-turn mowers, a skid steer and a brush mower. Being a stickler for maintenance, Bayles uses AMSOIL products in his vehicles and equipment.

Vehicles Must Face Brutal Texas Heat

His vehicles include a small fleet of half-ton and larger pickups that transport equipment to sites using gooseneck trailers. Working in the scorching Texas heat means BTB Services’ trucks are exposed to temperatures that frequently exceed 100°F (38°C) for a good part of the season. Combined with towing up to 30,000 pounds (13,607 kg), the company’s vehicles are the epitome of “severe-service” work trucks.

One such truck is a 2015 Chevrolet 2500 that Bayles bought in 2015. Bayles does as much maintenance as he can himself, including changing transmission fluid and filters. When the truck had about 50,000 miles (80,000 km) on it, Bayles switched the transmission to AMSOIL Signature Series Synthetic Fuel-Efficient Automatic Transmission Fluid.


Internal Transmission Filter Never Changed

Given the severe conditions, Bayles changes transmission fluid every 30,000 miles (48,000 km).

“I know that’s extreme, but we’re pulling about 30,000 pounds of weight behind the trucks,” he said. The maintenance strategy plus AMSOIL product performance have helped the truck eclipse 300,000 miles (483,000 km) with no issues.

Bayles changes the external, spin-on transmission filter on the Chevy 2500 every 60,000 miles (96,500 km).

However, since the transmission includes a drain plug and doesn’t require dropping the pan, he didn’t realize the transmission also has an internal filter, meaning it was never changed.

“I felt horrible that I had 300,000 miles on the truck and I never had the pan off,” said Bayles.

“Spotless! I can’t believe it.”

So, after 257,000 miles (413,600 km) using AMSOIL synthetic transmission fluid, Bayles dropped the pan to change the internal filter, unsure what he would find. The cleanliness of the pan and fluid amazed him; there wasn’t even a hint of sludge or deposits. He texted his AMSOIL Dealer, Erroll Ivery, an image of the clean pan and pristine fluid with the words, “Spotless! I can’t believe it.”

Transmission fluid still clean after Texas Heat and abuse of maximum towing.

The transmission pan and filter contained no sludge or deposits; the fluid still appeared in like-new condition.

Bayles said there wasn’t even a film of deposits or sludge on the transmission filter.

The Chevy 2500 has about 315,000 miles (507,000 km) on it now and still runs great. “Right now, I have it pulling a 32 foot trailer,” said Bayles. Including the payload, that adds up to about 22,500 pounds (10,200 kg). “I gave it a little bit of a break,” he said.

AMSOIL Synthetic Motor Oil Also Delivers Premium Protection

BTB Services has four trucks, two diesel and two gas, all of which use AMSOIL products in the engine, transmission, differentials and cooling systems. All the company’s diesel tractors use AMSOIL products, too. “We started using AMSOIL in our zero-turn this year,” he said.

Bayles performed oil analysis on the engine oil in his trucks, and the results showed the oil in his gas trucks still had 20% oil life following 20,000 severe-service miles (32,000 km), while the diesel oil still had 50% oil life after 10,000 miles (16,000 km).

AMSOIL products help Brian Bayles keep his trucks and equipment up and running, making money, which is vital for any business. “It definitely has helped keep the equipment well-maintained. I have never had any problems with the vehicles I maintain,” he said.

Bayles isn’t shy about telling others about his AMSOIL success story. “It’s a product I definitely highly recommend,” he said. “I believe in putting the best in all my equipment.”


How Does a Dual-Clutch Transmission (DCT) Work?

The Function of a Dual-Clutch Transmission

Market Technology before it’s ready!

A dual-clutch transmission (DCT) is synonymous with high performance. Compared to a traditional automatic transmission, it delivers…

  • Faster, smoother shifts
  • Increased fuel economy
  • Improved performance
  • Surprise breakdowns (well they’ll solve that soon)

Although the DCT transmission dates to the 1930s, it made its first practical appearance decades later in several 1980s-era race cars.

In 2003, the Volkswagen Golf Mk4 R32 was the first production vehicle to feature the technology.

Today you can find a DCT in a variety of cars, from the relatively tame Hyundai Sonata to the brash, sexy Nissan GT-R.

How a DCT transmission works

DCTs are essentially two manual transmissions working in tandem.

One gear shaft contains the even-numbered gears, and the other contains the odd-numbered gears. While you’re accelerating in first gear, for example, the computer selects second gear on the other gear shaft. When it’s time to up-shift, the clutch that controls the even gears disengages and the clutch that controls the odd gears engages.

Compared to a traditional automatic transmission, gears shift much more quickly and smoothly in a DCT transmission – the perfect complement to a powerful, high-performance engine.

While DCTs are capable of seamless shifts, they can suffer from shudder or lurching at slow speeds.

Transmission fluid with specific frictional properties is required to prevent shudder. DCT fluid must also maintain the proper viscosity to provide protection during the high-heat operation native to high-performance sports sedans and supercars.

100% Synthetic Dual-clutch Transmission Fluid (DTC)

Protect the thrill

AMSOIL 100% Synthetic DCT Fluid is specifically engineered for sophisticated dual-clutch transmissions.

Its superior frictional properties protect against shudder and gear clashing to consistently produce fast, smooth shifts. When you are waiting on the light you need a fluid engineered to solve the “constant slip mode” which is occurring to work as if it had a torque converter. Slight engagement while you are on the brakes requires beyond expectations technology you only can expect from AMSOIL.

AMSOIL Synthetic DCT Fluid’s exceptional durability provides stability in stop-and-go traffic and excels under intense, high-heat conditions. Its built-in oxidation resistance helps prevent sludge formation in vital transmission parts.

Available in our 98th St store. Just behind the Marlins at the Tea exit. Exit 73 Sioux Falls.

Lookup Your Vehicles


What is a CVT Transmission?

CVT Transmission? How Does It work?

“CVT” stands for continuously variable transmission. A CVT transmission uses a pair of variable-diameter pulleys and a belt or chain to provide unlimited gear ratios.

How does a CVT work?

To illustrate, think of a traditional automatic or manual transmission. They’re built with a defined number of gears, for example first through sixth (plus reverse). The transmission can operate in only one gear at a time. You typically feel a slight surge with each gear change.

CVTs, however, offer unlimited gear ratios.

Take a look at the image. You can see the metal belt connecting the two pulleys. Depending on engine speed and load, the computer automatically varies the pulley sizes to ensure the optimal gear ratio for the driving conditions.

CVTs use variable-diameter pulleys to create unlimited gear ratios.

CVT transmission pros and cons

What good does that do?

Imagine pedaling a bike. As you approach a steep hill, you adjust the shifters so a smaller chainring attached to the pedals is driving a larger sprocket on the rear wheel. This reduces the effort required to move the bike.

When you reach a stretch of flat road, you adjust the gear ratio again so a larger chainring attached to the pedals is driving a smaller sprocket. This helps achieve the perfect balance between energy expended and bicycle speed.

The same principle applies to a CVT, except the computer does all the thinking for you. When starting from a dead stop, it varies the pulley diameters (smaller drive pulley and larger driven pulley) so the engine can move the car as efficiently as possible. As you accelerate, it continuously varies the pulley sizes to keep the engine in its “sweet spot,” which results in improved fuel economy. Plus, you never feel the gear engagements because, in effect, there aren’t any.

CVTs gaining in popularity – but there are negatives

These benefits are why many car makers, including Nissan, Honda and Toyota are introducing more vehicles with CVTs.

There are drawbacks, however, including the “rubber-band effect” (you rev the engine, yet it takes a moment for vehicle speed to catch up) and lack of driver involvement (zero fun). In addition, most CVTs’ relatively diminutive parts can’t handle the power and torque of the truck or SUV you use to tow your boat or camper, which is why you find them mostly on smaller cars. Although there are some exceptions, as the list shows, which shows popular vehicles with a CVT.

What cars have a CVT transmission?

  • Honda Accord
  • Honda HR-V
  • Mercedes-Benz A- and B-Class
  • Nissan Altima
  • Nissan Pathfinder
  • Subaru Forester
  • Subaru Impreza
  • Subaru Legacy
  • Subaru Outback
  • Toyota Camry
  • Toyota Highlander Hybrid
  • Toyota Prius

Slip into something special

One look at the guts of a CVT and you can’t help but wonder how the belt doesn’t just slip wildly over the pulleys.

Believe it or not, the transmission fluid plays a major role in ensuring the belt or chain remains in contact with the pulleys without slipping.

That’s why CVTs require specialized CVT transmissions fluids, and not the traditional automatic or manual transmission fluid you probably have in your garage. CVT transmission fluids must be formulated with the correct frictional requirements to guard against slipping. Using the wrong fluid will reduce performance and potentially wreck your transmission.

Wear protection also important

Solid wear protection is also vital to maximizing CVT performance and life. That’s why we designed AMSOIL Synthetic CVT Fluid to fight wear and help extend transmission life.

To demonstrate, we pitted AMSOIL Synthetic CVT Fluid against Nissan NS-2 CVT Fluid in a field trial. After 100,000 miles, the belt lubricated with AMSOIL Synthetic CVT Fluid demonstrated minimal wear, as you can see in the images. This helps you get the best performance and most life out of your CVT.

The belt lubricated with Nissan NS-2 CVT Fluid demonstrated increased wear.

Buy AMSOIL Synthetic CVT Fluid

While driving purists may initially scoff at the notion of a transmission that requires no driver input, many eventually warm up to CVTs’ increased gas mileage and smooth operability.

If you’re one of them, make sure you protect it with a good CVT transmission fluid.

Should I Change Fluid in a Filled-for-Life Transmission?

What’s up with these “Filled-for-Life Transmissions”?

Casual motorists generally take no interest in crawling under their vehicles on a Saturday afternoon. And, when was the last time you heard someone express excitement over dropping their car off at the dealership for maintenance?

The automakers know this, which explains the proliferation of sealed, or filled-for-life, transmissions and differentials. Many vehicles also use “lifetime” factory fill fluids in these components that supposedly don’t require changing. Some transmissions and differentials don’t even include dipsticks or access plugs for checking the fluids.

The dirty little secret is that “filled-for-life” really means “filled for the life of the warranty.”

Suppose the “filled-for-life” transmission or differential on your truck fails after the factory warranty has expired. What do you think the dealership is going to do? That’s right – slide a bill across the counter to the tune of several thousand dollars.

It’s a good idea to change fluids in a filled-for-life or sealed transmission or differential at least once during its lifetime, and more often if you tow or haul. Here’s why.

Big power = increased heat

Modern vehicles are tougher on transmission fluid and gear lube than ever. For starters, the automakers are in an endless arms race to produce more power than the competition. All that added power has to go through the transmission and differential before reaching the wheels, yet modern transmissions are smaller and lighter than their predecessors. Meanwhile, the gears and bearings in most differentials remain unchanged despite the increased power they must handle.

This adds up to increased heat, and heat is one of the transmission fluid’s biggest enemies. It speeds the oxidation process and causes the fluid to chemically break down. Fluid that has broken down can cause sludge and varnish to form, which clogs narrow oil passages and can lead to stuck valves. Soon, your vehicle can begin to shift hard, hesitate or quit shifting altogether.

The situation is just as dire downstream of the tranny where heat and pressure wreak havoc inside the differential. Towing and hauling increase friction, which in turn increases heat. Extreme heat causes the gear lube to thin, reducing the effectiveness with which it keeps gear teeth separated and prevents wear. Thinner gear lube further increases friction, which causes heat to increase in a vicious cycle known as “thermal runaway.”

Lighter fluid, and less of it

Components also use lower-viscosity fluids to help boost fuel efficiency. That translates into thinner fluid protecting against intense heat and wear – not an easy task. In addition, many automakers use less gear lube than before to help reduce energy lost to friction and boost fuel economy.

Given such challenging conditions, what’s the best way to combat heat and stress to ensure your vehicle keeps running strong? Never change the fluids? Hardly.

“Filled-for-life” is misleading

In fact, your “lifetime” fluid may require changing if your driving habits full under the “severe” designation, which includes towing and hauling.

The differential in the 2016 Ford Super Duty 250, for example, is considered “filled for life.” However, the owner’s manual instructs you to change the fluid every 50,000 miles (80,467 km) in “severe” conditions and anytime the differential is submerged in water.

Did you hear that, anglers?

The 2017 Toyota Tundra likewise features a “filled-for-life” differential. But Toyota tells you to change fluid every 15,000 miles (24,140 km) if towing.

Complicating matters, some vehicles don’t even include a service schedule for changing transmission fluid. The Mazda CX-5 is one example. That doesn’t seem like a great idea if you plan to keep the vehicle past its factory warranty period.

For maximum life and best performance, change the “lifetime” fluid in your vehicle’s filled-for-life or sealed transmission or differential at least once, but more often if your driving conditions fall under the severe designation.

Changing fluid in these units may tax one’s mechanical aptitude, but it can be done. You likely need to visit the dealer or a mechanic since special tools can be required. Some manufacturers also prescribe complicated procedures spelled out in a service manual for changing fluids.

Anyone who has changed gear lube before – whether on a “filled-for-life” differential or traditional unit – knows the hassle involved: a tough-to-reach fill hole, gear lube spilled everywhere and bloody knuckles.

Find out how often to change gear lube here.

Our SEVERE GEAR easy-pack offers the perfect solution. Compared to rigid conical bottles that waste a quarter of the gear lube or more, our easy-pack offers the dexterity to maneuver around vehicle components and the flexibility to install nearly every drop of gear lube. It eases the process of changing gear lube, saving you time and hassle.