What Can Cause a Car to Leak Transmission Fluid?

A vehicle’s transmission fluid system is closed, which means that the fluid or oil inside can’t escape when things are working properly. Therefore, when vehicles leak transmission fluid, it indicates another problem than just a need to add more fluid or oil. If your transmission leaks, however, don’t automatically assume the worst. There is a wide variety of causes for a leaking transmission, ranging from simple fixes to fairly serious issues. That doesn’t mean you should put off having your vehicle inspected. Even delaying easy repairs can lead to greater problems when ignored, which will ultimately cause a bigger headache and blow to your pocketbook later. Here are the most common causes of a transmission fluid leak:

  • Loose pan: The transmission oil or fluid pan is designed to catch extra fluid that would otherwise escape, so – if the pan is loose – there is nothing to prevent transmission leaks. The pan may simply not have been bolted back correctly after changing the filter or come loose while driving over rough terrain.

  • Oil pan gasket: High temperatures or faulty manufacturing can lead to a cracked or otherwise damaged oil pan gasket. Although this part is inexpensive to replace, more serious problems can ensue if the issue is left unattended.

  • Misaligned drain plug: After a transmission fluid flush or other transmission service, the drain plug may not have been screwed back in properly along the threads. This can lead to a leaking transmission but is relatively easy to set aright.

  • Damaged bell housing: When driving on gravel roads or on other challenging surfaces, it is possible for a rock or other item to strike the bell housing with such force that it becomes cracked or develops a hole where transmission fluid can escape.

  • Punctured or cracked fluid lines: Similarly, items picked up from the road and flung by the tires can strike the transmission fluid lines and cause transmission leaks.

  • Faulty torque converter: Less commonly, the torque converter, which is responsible for switching gears in automatic transmissions, may be damaged and allow transmission leaks. Unfortunately, this is a costly repair that is also difficult to diagnose.

Unless you are checking your car or truck’s fluid levels as part of general maintenance or notice your gears aren’t shifting as usual, you may not even know your vehicle’s transmission leaks. Another sign that there is a transmission oil leak is the accumulation of a red, slick liquid beneath your car, which may be the size of a small coin or much larger, depending on the severity of the transmission fluid leak. If you know your fluid is low or have seen evidence of a leak in a parking lot or driveway, call us for a consultation with one of our experienced mechanics. He or she can help diagnose the cause of your leaking transmission and make appropriate recommendations for repairs.


Next Step

Schedule Transmission fluid is leaking Inspection

The most popular service booked by readers of this article is Transmission fluid is leaking Inspection. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Transmission fluid is leaking Inspection reviews

Excellent Rating

(194)

Rating Summary
184
5
0
1
4
184
5
0
1
4

Hugh

11 years of experience
60 reviews
Hugh
11 years of experience
Chevrolet Astro V6-4.3L - Transmission fluid is leaking Inspection - Denver, Colorado
Excellent and knowledgeable mechanic. Told me all I needed to know about the problems with my vehicle. Thank you Huge!

Charles

4 years of experience
80 reviews
Charles
4 years of experience
Jeep Patriot L4-2.4L - Transmission fluid is leaking Inspection - Madison, Tennessee
Charles was awesome! He took time to answer all my questions and gave wonderful advice and guidance. I’ll absolutely call on him again!

Simon

27 years of experience
218 reviews
Simon
27 years of experience
Chevrolet Silverado 1500 V8-5.3L - Transmission fluid is leaking - Upper Marlboro, Maryland
Simon, was a breath of fresh air...he was professional, very knowledgeable. In addition, he actually showed me what he'd found and explained the possible cause as well the end result. He reminded me of my military days :)

Randy

22 years of experience
69 reviews
Randy
22 years of experience
Dodge Grand Caravan V6-3.3L - Transmission fluid is leaking - Cape Coral, Florida
Randy was extremely informative and patient. My van got stuck up the street 4 minutes from my house and Triple A was over 3 hours late to tow it home. Randy was willing to go check it out where it was. This guy definitely needs a raise!!!!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How Long Does a Transmission Filter Last?
Your Your transmission filter is a very important component in your vehicle, because it’s the front line of defense when it comes to keeping contaminants out of your transmission fluid. Most automobile manufacturers recommend a transmission filter change every 2...
How a Cable Clutch System Works
If If you drive a car with a manual transmission, you know that to get your car moving, you depress the clutch pedal, choose a gear, and then give the vehicle a bit of gas. But have you ever wondered...
How Does a Fuel Injection Flush Work?
Fuel Fuel injectors, as their name implies, are responsible for getting fuel into the engine. Fuel injection systems either work via a throttle body containing as few as 2 injectors, or go straight into the port with one injector per...

Related questions

My 745li won't stay in gear.

Hi there. The computer (ECM) is locking out the transmission from engaging a drive mode. When this happens, something inside the transmission has failed, like a solenoid or the pump pressure is low. Check the transmission fluid and make sure...

all the tranmission fluid burned out, dip stick was black, burning smell. new tranmission installed, a line was punctured on insta

Have the vehicle checked after filling the transmission. You should not let the fluid get low on the new transmission. You may need to have the vehicle run on a lift to see where the leak is. If you need...

I hear a grinding noise when turning left

You should have a brake inspection performed to verify the thickness of your brake pads; you may need new brake pads and/or rotors. An inspection from a qualified technician, such as one from YourMechanic, can investigate the cause of the...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com