To check transmission fluid on a vehicle with a dipstick, warm the engine up, park on level ground, set the engine and shifter the way your owner’s manual specifies (usually engine running, in Park), then pull the dipstick, wipe it, reinsert it fully and read the level against the marks. Check the color and smell at the same time, because fluid condition tells you as much as the level does. Procedures differ by manufacturer, so the owner’s manual is the final word for your vehicle.
How do you check transmission fluid with a dipstick?
- Warm it up. Drive for several miles or let the engine reach normal operating temperature. Fluid expands as it heats, and most dipsticks are marked for warm fluid.
- Park on level ground and set the parking brake. A slope tilts the fluid in the pan and gives a false reading.
- Set the engine and shifter as specified. Many vehicles are checked with the engine running and the shifter in Park, some call for Neutral, and some models are checked with the engine off. Follow the owner’s manual.
- Find the transmission dipstick. It is separate from the engine oil dipstick. On rear-wheel-drive trucks it is usually toward the back of the engine bay; on front-wheel-drive cars it is often near the transaxle on one side. The handle is often labeled.
- Pull, wipe, reinsert, pull again. Wipe the dipstick with a clean, lint-free rag, push it all the way back in, then pull it out and read where the fluid sits.
- Read the right range. Many dipsticks have separate cold and hot ranges or a crosshatched area. With fully warm fluid, the level should be within the hot range.
- Check the condition. Wipe a drop onto a white paper towel to see its true color, and smell it.
If the level is low, add only the fluid type your owner’s manual specifies, in small amounts through the dipstick tube with a clean funnel, rechecking as you go. Do not overfill; too much fluid can foam and cause shifting problems of its own. An automatic transmission does not normally use up fluid, so a low level usually means a leak that should be found and fixed.
What if there is no transmission dipstick?
Many newer vehicles have a sealed transmission with no dipstick under the hood. These units are typically checked from underneath at a check or fill plug, with the vehicle level, the engine running and the fluid at a specified temperature, which often has to be read with a scan tool. Our guide on how often to change transmission fluid explains the check-plug method, and our 4L60E transmission fluid capacity guide covers fill amounts for one common GM transmission. Because it is easy to get the level wrong on a sealed unit, many owners leave this check to a shop.
Transmission fluid color chart
Most automatic transmission fluid is dyed red so it is easy to tell apart from other fluids. Use the chart below as a general guide. Not every fluid starts out red, particularly some CVT fluids, so compare against fresh fluid of the type your manual specifies.
| Color or condition | What it can indicate | What to do |
|---|---|---|
| Bright red or pink, translucent | New or healthy fluid | Keep to the service schedule in your manual |
| Darker red or light brown | Normal aging; the fluid is wearing out | Check the service history and plan a fluid service |
| Dark brown or black, burnt smell | Overheating, worn friction material or very old fluid | Have the transmission inspected |
| Milky, cloudy pink (often described as a strawberry milkshake) | Possible coolant contamination, for example from a leaking transmission cooler inside the radiator | Avoid driving and have it diagnosed promptly |
| Foamy or bubbly | Overfilling or the wrong fluid type | Recheck the level and fluid type; have it diagnosed if it continues |
| Visible particles or metallic flakes | Internal wear | Have the transmission inspected |
What does the smell of the fluid tell you?
Fresh fluid has a mild, oily smell. A sharp, burnt smell, often compared to burnt toast, points to fluid that has been overheated, usually from slipping clutches, heavy towing or a cooling problem. Burnt fluid has lost much of its ability to protect the transmission, and the cause of the heat matters more than the fluid itself. Our transmission fluid temperature guide explains what makes a transmission run hot.
When should a shop look at it?
- The level keeps dropping between checks
- The fluid is dark or burnt well before its service interval
- The fluid looks milky or pink and foamy
- You notice slipping, harsh or delayed shifts, or a transmission warning message
Low or damaged fluid is a common cause of slipping, and our guide to transmission slipping signs and causes covers the warning signs. If a shop finds internal damage, you can compare complete replacement units on our transmissions by code page.
Related guides: transmission fluid color chart · transmission fluid leak · transmission solenoid symptoms · limp mode.
More guides: delayed engagement · transmission noise · which fluid your transmission takes · checking transmission fluid without a dipstick · how much transmission fluid to add.
Trouble codes: P0868 Transmission Fluid Pressure Low · P0730 Incorrect Gear Ratio · all OBD2 codes.
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