Introduction
Transmission fluid is a vital component of any vehicle’s transmission system. It serves several crucial functions, including lubricating the transmission’s internal components, transferring heat, keeping parts clean, and more. When transmission fluid is in good condition, it can help ensure smooth gear shifts and operation. That’s why routinely checking the transmission fluid using the dipstick is an important part of vehicle maintenance.
The dipstick provides a quick way to check on the level and condition of transmission fluid without having to drain the whole system. By examining the fluid on the dipstick, you can get an idea of whether you need to add more fluid or if there are any issues requiring attention. But to accurately assess transmission fluid condition, you need to know what to look for.
What Should Transmission Fluid Look Like?
Here are the key things to check when examining transmission fluid on the dipstick:
Color
The color of transmission fluid offers clues about its condition. As fluid ages and deteriorates, the color tends to become darker.
– New, unused transmission fluid is usually red, maroon, or pinkish in color. This is the ideal shade.
– Light brown or tan fluid could indicate the beginning stages of wear, but may still be fine.
– Dark brown or black fluid is a sign of old, oxidized fluid that likely needs changing. It indicates the fluid has been contaminated and broken down over time.
The exact colors can vary between transmission fluid types and vehicle makes. It’s a good idea to be familiar with what the fluid looks like when healthy in your particular vehicle.
Clarity
Transmission fluid should appear clear, without any cloudiness or opacity. Cloudy or opaque fluid can mean there is contamination from water, dirt, debris or wear particles. These contaminants can damage transmission components, so cloudy fluid is a sign you need to have the system inspected and fluid changed.
Level
The dipstick has marks to indicate the proper level range for transmission fluid. The fluid should be somewhere within the designated “hot” range when warm. If it is below the indicated range, you need to top it off. A fluid level that is too high or too low can cause shifting problems.
Odor
Transmission fluid should have a distinctive odor that some describe as sweet or tart. If the fluid smells burnt or rancid, it could be contaminated and in need of changing. Pay attention to any shift in odor compared to what it normally smells like.
When to Check Transmission Fluid
Checking the transmission fluid regularly provides the best window into how it is holding up:
– Check every month or few thousand miles for manual transmissions.
– Check every month or 6,000-10,000 miles for automatic transmissions.
Also check the fluid if you notice any changes in how your transmission performs, such as odd noises, grinding or difficulty shifting. It’s best to check automatic transmission fluid when the engine is warmed up and running, usually after driving for about 15-20 minutes. Follow the steps in your vehicle repair manual.
You want to verify the fluid is at the right level and appears in good condition when warm. If it needs topping off, only add fluid specifically recommended for your make and model. Never overfill the transmission.
What Issues Can Low Transmission Fluid Cause?
Driving when transmission fluid is low can create both short-term and long-term problems. Here are some of the most common issues:
– Hard shifts – Transmission may clunk or jerk as gears change.
– Delayed engagement – Slipping between gears and hesitation as transmission struggles to engage next gear.
– Overheating – Fluid cools and lubricates the transmission. Low levels can lead to overheating and eventual internal damage.
– Leaks – Running low could indicate a leak in a line, gasket or seal. Leaks need to be fixed and fluid replaced.
– Failure – Severely low fluid can allow gears to grind or transmission to slip excessively, accelerating wear and eventually causing catastrophic failure.
Refilling the fluid may temporarily help some drivability issues, but if you suspect low fluid be sure to have the transmission inspected. A leak or larger underlying problem could require transmission repair.
What Issues Can Contaminated Fluid Cause?
Contaminated transmission fluid can also create driveability and performance problems:
– Slipping – Contaminants make it harder for transmission to smoothly engage gears.
– Shuddering – Damage to clutch packs and gears from contaminated fluid cause uneven gear engagement.
– Overheating – Clogged fluid channels and reduced lubrication abilities lead to overheating.
– Leaks – Contaminants abrade seals, allowing leaks to develop.
– Corrosion – Fluid contaminants can be acidic and corrode transmission components from the inside.
– Failure – Just like low fluid, contaminated fluid accelerates wear and can quickly lead to complete transmission failure.
Many transmission problems start small but can quickly snowball. If you notice any symptoms suggesting issues, get the transmission inspected right away. A full flush and fluid change is often the fix for contaminated fluid.
How to Perform a Transmission Fluid Change
If your transmission fluid check shows signs of being contaminated, old or compromised, a complete fluid change is needed. Here are the steps involved:
Materials Needed
You’ll need these supplies:
– New transmission fluid – Use what is specified for your vehicle. Check owners manual if unsure.
– Funnel – Used to pour new fluid into fill hole.
– Drain pan – Catches old fluid as it drains out. Should have capacity of 6-10 quarts.
– Gear oil pump – Used to draw old fluid out of dipstick tube. Can substitute plastic tubing if you don’t have pump.
– Jack stands – Support vehicle once lifted.
– Floor jack – Safely lifts front of vehicle.
Optional items include mechanic’s gloves to protect hands and wheel chocks to prevent rolling.
Draining the Old Fluid
Follow these steps to drain out old fluid:
1. Run engine to warm up fluid – About 10-15 minutes, long enough for fluid to reach operating temperature.
2. Raise front of vehicle – Use the floor jack to safely lift the front and place jack stands under frame.
3. Remove transmission fluid dipstick – Have drain pan ready to catch any fluid that spills out.
4. Attach pump/tubing to dipstick tube – Insert pump or plastic tubing into tube to start drawing out old fluid.
5. Drain fluid – Allow all old fluid to drain out until pump/tube stops pulling fluid.
6. Check drain plug – Make sure plug is tight and not leaking.
7. Reinstall dipstick once drained – Use a clean lint-free rag to wipe off dipstick before reinserting.
Refilling with New Fluid
Follow this process for adding the new transmission fluid:
1. Add fluid – Pour carefully and slowly using the funnel. Stop periodically to check fluid level on dipstick.
2. Fill to proper level – Keep adding fluid until dipstick reads between low and full marks. Do not overfill.
3. Start engine – Run engine a few minutes to circulate the new fluid throughout the system.
4. Recheck level – Transmission level settles after running. Recheck and top off as needed.
5. Check for leaks – Examine transmission pan, lines and dipstick area to make sure no new leaks have formed.
6. Reset drain interval – Clear your fluid service reminder if your vehicle has one.
7. Test drive – Take vehicle through all gears to make sure transmission operates smoothly.
Signs a Transmission Fluid Change is Needed
Don’t wait until major problems start occurring. Watch for these signs a transmission fluid change should be scheduled:
– Fluid is dark, opaque or smells burnt.
– You’ve exceeded your vehicle’s recommended fluid change interval.
– Problems like slipping or hesitation develop.
– Leaks are present.
– Vehicle surpasses 100,000 miles without a fluid change.
– Transmission repairs have been performed recently.
– You use your vehicle for towing or hauling regularly.
Following the manufacturer’s fluid change intervals can help maximize transmission life. Typically fluids need changed every 30,000-60,000 miles in normal driving.
Conclusion
Checking transmission fluid using the dipstick is a simple way to identify potential problems and head off repairs. Know what healthy fluid looks like in your vehicle – it should be reddish, translucent and free of odor. If the fluid is contaminated, burnt or running low, have your transmission fully inspected and flushed to help restore proper operation. Keep up with fluid changes as recommended to help ensure your transmission lasts.
Frequently Asked Questions
Should transmission fluid be cherry red?
Transmission fluid when new and healthy typically ranges from cherry red to maroon, pinkish or bright red in color. This bright red hue indicates fresh, high-quality fluid. As fluid ages and becomes contaminated, it tends to turn progressively darker.
Why is my transmission dipstick smelling burnt?
A burnt or rancid smell from transmission fluid usually indicates it has become overheated and oxidized. This burnt fluid has lost much of its lubricating properties and cooling abilities, which can quickly damage internal transmission components. Often a burnt smell means the fluid needs to be changed immediately.
What color is low transmission fluid?
Low transmission fluid may appear streaked with metallic particles or have a blackish, dark brown appearance. Healthy fluid is generally red, pink or maroon. If fluid is low, discolored and contaminated looking, the transmission needs professional inspection along with a flush and fluid change.
Should I drive a car with low transmission fluid?
It’s best not to drive any significant distance with low transmission fluid. Letting the fluid run too low can allow internal transmission parts to grind, slip excessively and overheat – causing accelerated wear, damage and eventual failure. Have the fluid level checked and add or change fluid as needed before driving.
Can dirty transmission fluid be flushed?
Yes, contaminated or dirty transmission fluid can be flushed from the system. A transmission fluid exchange procedure is performed to pump all the old fluid out while refilling with new fluid. This removes sludge and deposits for a clean fluid supply. However, if internal damage already exists from contaminated fluid, further repairs may be necessary.
Summary
Checking transmission fluid using the vehicle’s dipstick provides a quick method to monitor condition and head off potential problems. When examining the fluid, look for signs of overheating, contamination and low level. Transmission fluid should appear clean, red in color and free of burnt odors.
If deterioration is noticed, have the system drained, flushed and refilled with fresh fluid immediately. Contaminated fluid accelerates wear inside the sensitive transmission components. Stay diligent with your scheduled transmission fluid changes as well to help maximize performance and service life.
