Transmission Fluid Diagnosis

Transmission fluid is typically a clear reddish pink colour when new, and over the course of its life that colour can change quite a bit, meaning different things are occurring.

The first step is to make sure you’re actually checking your transmission fluid properly in order to get an accurate reading. When checking your vehicle’s transmission fluid, first consult your owner’s manual and follow their procedure for fluid level checking. Many different manufacturers require differing methods (ie – engine running, in park, etc). It’s best to use a white paper towel when checking and do at least 2-3 dips of the stick (wiping it down between dips) to ensure an accurate reading.

• Good level and good condition: If your transmission fluid is to the full mark and a clean reddish pink colour, then the fluid is in good condition. You could still have a problem with your transmission, but it has not yet affected the fluid condition.
• Low level and good condition: If your transmission fluid is low, there is a leak. Unlike your engine which can “consume” oil due to normal use, a transmission is a sealed unit. Have your transmission inspected as soon as possible to avoid internal damage.
• Good level but brown colour: If your transmission fluid has a brownish tinge and a slightly burnt smell to it, then there is a problem. It could be just that the fluid is very old and no longer protecting the transmission’s internal components properly, or there are worn components causing excess friction and heat. Have your transmission inspected as soon as possible to avoid internal damage.
• Good level but black colour: If your transmission fluid has a black colour and a burnt smell to it, there is an internal problem. This would be caused by excessive heat due to internal friction. Have your transmission inspected as soon as possible to avoid further damage.
• High level and pink foamy appearance: If your transmission fluid is high and has a “strawberry milkshake” look to it, then there is a problem. This is usually caused by a failure in your radiator. The transmission fluid is cooled by a cooler built into your radiator. Sometimes when the radiator fails, engine coolant is allowed to cross-over into the transmission cooling tubes and contaminates the transmission fluid. Have your transmission inspected as soon as possible to avoid further damage.

It’s important to remember that due to the complexity of today’s computerized transmissions, that just because the transmission appears to be malfunctioning doesn’t mean the actual problem is in the transmission. Your vehicle’s computer gets signals from up to 32 separate sensors throughout the vehicle’s other systems and any one of these could be sending inaccurate or no information.

If you’re experiencing any sort of transmission problem, please contact your local Mister Transmission and book an appointment for our FREE 21-Point Multi-Check Inspection.