Check a transmission fluid service quote

What the job usually involves.

In a drain-and-fill the technician removes the drain plug, lets the fluid run out and refills with the same amount. A pan and filter service also removes the oil pan so the filter or strainer can be replaced and the pan cleaned before a new gasket goes on. Many units have no drain plug, so removing the pan is the drain; on some the filter is built into the pan and the pan is replaced as one part.

An exchange usually uses a machine connected to the cooler lines to push new fluid in while old fluid comes out. On many newer transmissions the level is then set with the engine running and the fluid at a specified temperature, which may need a scan tool.

A manual transmission is usually drained and refilled through its drain and fill plugs with the gear oil or fluid the manufacturer specifies. Some dual-clutch transmissions use more than one fluid, so check that the quote names each one.

What a complete written quote should state.

• The method: drain-and-fill, pan and filter service, or exchange.
• The fluid specification and the quantity billed.
• Whether a filter or strainer and a pan gasket or drain plug seal are replaced.
• Which units are serviced: transmission, transfer case, differential.
• How the fluid level will be set and checked.
• Any cleaner or additive, by name, as its own line.
• Labor as hours or a flat price, shop supplies, disposal fees and tax.

SourceFederal Trade Commission — Auto Repair Basics ↗ (opens an external site)

What changes the total.

The method changes the total most: an exchange usually uses more fluid than a drain-and-fill, and a filter service adds parts and time. The fluid itself matters too, since some transmissions call for a specific fluid rather than a general one.

The transmission type and how the level is checked affect the labor. Whether a transfer case or differential is serviced at the same visit, the local labor rate and tax account for the rest.

Drain-and-fill, filter service or exchange?

A drain-and-fill replaces only the fluid that drains from the pan; the rest stays in the torque converter, cooler and passages, which is why some shops repeat it. A pan and filter service adds a look at the pan and a new filter where one can be reached. An exchange replaces more of the fluid in one visit.

None of these is automatically right for every vehicle. The manufacturer's service information says which method and fluid apply, and many schedules list a shorter interval for severe use such as towing or frequent short trips. Ask which one the quote follows and compare quotes that use the same method.

Many quotes print “flush” for a machine exchange, and some flush services also add a cleaning chemical. Some manufacturers do not approve cleaners or additives in their transmissions, so ask which product is used and whether the service information allows it.

When a second opinion is worth it.

• The quote says “transmission service” without naming the method or the fluid.
• An exchange is recommended with no reference to the manufacturer's schedule or a fluid check.
• The fluid named on the quote differs from the one in the owner's manual.
• A filter is listed on a transmission where the shop cannot say how it will be reached.
• A fluid service is offered as the fix for a shifting problem that has not been diagnosed.
• A cleaner or additive is added to the service without being named on the quote.