An Intro to Replacing Manual Transmission Fluid

Brian Jones

March 20, 2025

4 min read

Brian Jones

March 20, 2025

4 min read

An auto mechanic drains old transmission fluid.

Replacing manual transmission fluid on a schedule ensures smooth shifts and optimum performance. We recommend changes every 30,000 and 60,000 miles. However, some brands say it should happen every 15,000 miles. That’s typical if your vehicle tows, hauls heavy loads, goes off-road, or operates in extreme temperatures.

Some modern vehicles have a “lifetime fill” that never needs to be changed. For example, BMW offers this feature on some models. Regardless, if you experience problems with your transmission, you should change the fluid. That’s true whether or not the manufacturer says you have “lifetime” fluid.

How much does it cost to replace manual transmission fluid?

A quart of manual transmission fluid costs between $10 and $30. See our buyer’s guide for a description of that type to buy. The number of quarts to buy depends on your vehicle. Expect between two and five quarts.

The tools needed to perform the replacement include a standard wrench and socket set, a jack and jack stands, shop towels, and a drain pan. If you have these basic tools, the only expense is the fluid. That will come at a significant savings compared to getting transmission fluid replaced at a shop, which could cost $150 to $400 on parts and labor, depending on your model.

See our transmission fluid buying guide - opens in new window or tab..

Manual Transmission Fluid vs. Automatic vs. Gear Oil

The red spout of a transfer pump inserted into the filter neck of a vehicle's transmission. — If there’s sufficient room, insert the spout of the gear lube bottle into the transmission filler neck. Most vehicles require a transfer pump.

Automatic transmission fluid (ATF) is not the same as manual transmission fluid (MTF).
ATF is thinner than MTF and employs different additives.

Older vehicles use gear oil in their manual transmissions. MTF and gear oil come in the same weights, but they use different additives. Beware that some additives in gear oil could damage the brass synchromesh used in modern transmissions.

Gear oil comes in various grades and weights—from GL-1 to GL-5.

GL-1 has the fewest additives and is rated for the least pressure. GL-4 might be specified for use in a manual transmission or transfer case, while GL-5 might be used in a differential or axle. Refer to your owner’s manual for which fluid is compatible with your vehicle.

Signs It’s Time to Change the Manual Transmission Fluid

Five new bottles of Motul synthetic gear oil. — Motul synthetic gear oil

Regardless of your vehicle's use as a commuter car or long-range highway cruiser, manual transmission fluid degrades over time. Follow regular changing intervals. But you may also want to replace your transmission fluid if you notice these symptoms:

Burning smell: If the fluid smells burnt, it indicates that the fluid is no longer properly lubricating the transmission.

Grinding sounds: When the gears aren’t adequately lubricated, the gear will grind when you shift. A poorly lubricated transmission can also start clunking or whining.

Slipping gears: While stick-shifts won’t slip like an automatic transmission, low or contaminated fluid can force the car out of gear.

Trouble shifting gears: If shifting becomes rough, sticky, or stiff, contaminated transmission fluid may be the problem.

Check the condition of the transmission fluid to see how it looks. Fresh manual transmission fluid should be translucent and brown or have a slight red tint, depending on the type. As it becomes contaminated, the fluid turns dark brown or completely black.

Does the manual transmission have a filter?

Unlike the automatic transmission, manuals don’t typically have a filter. Because manuals don’t have the same hydraulic components as automatics, there aren’t as many contaminants that require filtration. However, some manual transmissions use a magnetic drain plug to catch metal shavings. You should clean it during the fluid change.

The process of replacing manual transmission fluid is very similar to the instructions detailed in our video and guide on how to change the transmission fluid - opens in new window or tab.. The simple job should take less than 30 minutes.

A mechanic slides a floor jack under a red vehicle. — Replacing manual transmission fluid requires a floor jack and jack stands.

While changing the transmission fluid, give the system a full check. Look carefully for leaks around the transmission case, gaskets, and seals. By catching leaks early, you can replace the gaskets or seals before refilling the system. You should also clean the magnetic drain plug to remove metal shavings.

Also, check the clutch and linkage, especially if you have been having trouble shifting. Lubricate any accessible linkage points and adjust the clutch if needed. You can also inspect the transmission mounts to ensure there’s no vibration or rough shifting.

This is also a good time to replace the gear oil in your differentials.

Basic tools to complete the job include a floor jack, socket and ratchet, jack stands, and a drain pan.

About the author

Brian Jones

Brian worked for several decades as an ASE Certified Master Technician in dealerships before starting his used car lot. Today, he writes for top automotive publications including Motor1. In his spare time, he's dreaming of an escape to the country's best trails in an off-road beast.

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This article is meant to provide general guidance only. Automotive maintenance, repair, upgrade, and installation may depend on vehicle-specifics such as make and model. Always consult your owner's manual, repair guide for specific information for your particular vehicle and consider a licensed auto-care professional's help as well, particularly for advance repairs.