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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.

How Often Should I Change Front or Rear Differential Fluid?

When to change differential fluids

 

It depends on your vehicle, driving conditions and differential fluid quality.

That’s a pretty vague answer, but it’s true.

If you drive your truck primarily on the highway in temperate conditions and rarely tow or haul, you likely don’t need to change front or rear differential fluid very often. But, if you tow a work trailer or haul supplies frequently and the temperature fluctuates as wildly as your health insurance premium, then you need to change the fluid more often. The only way to know the exact mileage interval is to check your owner’s manual or visit the dealership.

Bigger, faster, stronger

Why the varying fluid change intervals? Because severe operating conditions break down differential fluid more quickly and place greater stress on the gears and bearings, inviting wear.

The truck manufacturer’s ongoing arms race for the highest towing capacity has resulted in trucks that place far more stress on differentials than their predecessors. Meanwhile, differential fluid capacities have largely decreased or remained the same.

For example, compare a 1996 Ford F-250 Crew Cab to the 2017 version. Back in 1996, maximum towing capacity was 10,500 lbs. using a rear differential that held 3.75 quarts of gear lube. The 2017 model offers a 15,000-lb. towing capacity using a rear differential that holds 3.5 quarts of fluid.

Greater towing capacity, less gear lube

What does that mean for your truck? It means less fluid is responsible for guarding against increased heat and stress. In this environment, inferior lubricants can shear and permanently lose viscosity. Once sheared, the fluid film weakens, ruptures and allows metal-to-metal contact, eventually causing gear and bearing failure.
And in Sioux Falls looking out over 12th St every day, I see a lot of people overloading their light duty pickups!

Increased temperatures are also a challenge. As temperatures climb, gear lubricants tend to lose viscosity, while extreme loads and pressures can break the lubricant film, causing increased metal-to-metal contact and heat. The increased friction and heat, in turn, cause the lubricant to lose further viscosity, which further increases friction and heat. Friction and heat continue to spiral upward, creating a vicious cycle known as thermal runaway that eventually leads to greatly increased wear and irreparable equipment damage.

That’s why you need to change differential fluid more often in severe operating conditions.

In our example above, Ford recommends changing differential fluid every 150,000 miles in normal service. But they drop the change interval significantly – to every 30,000 miles if using non-synthetic fluid – when towing frequently at wide-open throttle and driving at temps above 70ºF. Those restrictions apply to just about anyone who’s pulled a camper/boat/trailer anywhere in North America during most of the year.

Bottom line…

Use a high-quality synthetic gear lube to maximize your truck’s ability to tow and haul.

AMSOIL Severe Gear 75W-110 ® Synthetic Gear Lube, Severe Gear 75W-90 (Best seller) and Severe Gear 75W-140 are specifically designed for severe service. It maintains viscosity better than other conventional and synthetic gear lubes despite rigorous use and it contains advanced anti-wear additives for further protection. It also costs less than most OEM-branded gear lubes.

FIND AMSOIL SYNTHETIC GEAR LUBE FOR MY TRUCK

Stay safe out there and visit our Sioux Falls AMSOIL Store at 4610 W. 12th St. (Just west of I29 about 1-block)  605-274-2580

 

Sold on AMSOIL – Now He Is A Dealer

DEALER: ‘EVERYTHING RUNS BETTER, LASTS LONGER’

How could it be you might ask? The answer lies in the devotion to manufacturing products of the highest possible quality and not reduced to increase profits. The position for a company to do that is risky these days but it’s why AMSOIL customers travel many miles to buy. About a quarter of our Sioux Falls customers come from areas over 25 miles away.

Dealer Robert Lolato of Orleans, Ontario, Canada has been a believer in AMSOIL products for more than 20 years.

He started using AMSOIL products in 1985. “I can tell you firsthand that my experience with AMSOIL products has been phenomenal,” he said. “Everything runs better and lasts longer. That’s why I decided in 2013 to become a Dealer — to help other people experience the benefits of using AMSOIL products.”

Loaded truck for towing

Lolato uses his 2009 GMC* 2500 HD Crew Cab* short-bed 4X4 diesel truck to haul a fifth-wheel camper. He installed AMSOIL Premium 15W-40 Synthetic Diesel Oil (DME) and an Ea® Oil Filter at the first oil change.

At 50,000 kilometers, he installed AMSOIL synthetic lubricants throughout the drivetrain of the truck:

Front Differential: AMSOIL Severe Gear® 75W-90 Synthetic Extreme Pressure (EP) Gear Lube (SVG)

Transfer Case: AMSOIL Signature Series  Fuel-Efficient Synthetic Automatic Transmission Fluid (ATL)

Transmission: AMSOIL Signature Series Fuel-Efficient Synthetic Automatic Transmission Fluid (ATL)

Rear Differential: AMSOIL Severe Gear 75W-90 Synthetic Extreme Pressure (EP) Gear Lube (SVG) All

Grease Fittings: AMSOIL Synthetic Multi-Purpose Grease (GLC)

Fuel Treatment: AMSOIL Diesel Injector Clean (ADF) in spring, summer and fall and AMSOIL Diesel Injector Clean + Cold Flow (DFC) in the winter months. When he tows the 12,000-pound fifth-wheel, Lolato uses AMSOIL Diesel Cetane Boost (ACB).

“My truck has 149,000 kilometers, and I tow a 38-foot fifth-wheel in the hot summer with no problem,” Lolato said. “And it starts in winter at minus 45 degrees without plugging it in.”

He changes the oil about every 15,000 kilometers, depending on fuel dilution. “I am getting better fuel mileage,” Lolato said. “There’s no lack of power, even when towing in hilly terrain, and it runs cool in the hot summer months when towing.”

His rig sparks interest and questions about the quality of AMSOIL products. “When people see my truck with the AMSOIL stickers on the back window, I show them the clean tailpipe on the truck and they can’t believe it’s a diesel. I also tell them the fuel mileage I get on the highway (25 mpg, not towing) and how cool the engine and transmission are when towing (78°C transmission, 100°C engine).”

Lolato also uses AMSOIL products front to back in his 2006 Mazda 3* hatchback with a 2.3L engine and his 2017 Hyundai Elantra* with a 2.0L engine.

Value Saves you Money

I’m always quick to correct a prospect when they say, “Well AMSOIL is great but only for those who are in the upper income brackets.” – Not true. Actually if I had to put a label on a majority of our “non-enthusiast” customers it would be the thrifty type who don’t let a dollar go to waste. AMSOIL saves money in so many aspects. Try and see for yourself.