How Much Is Too Much Transmission Fluid In My Car?

The age-old saying, "It's always better to have too much than not enough" applies to many things in life. Food at a party; money in your wallet; room in your house. But when it comes to your transmission's fluid levels, having too much transmission fluid inside could actually be a very bad thing for your car and for you.

So, before you start pouring in another quart of transmission fluid into the dipstick tube, pay close attention so you don't accidentally turn a good deed into a nightmare situation.

Why do I need to worry about my vehicle's transmission fluid?

The amount of transmission fluid in your vehicle is extremely important because this fluid acts as a lubricant to make your car engine run smoothly. The fluid reduces friction within your transmission, allowing your vehicle to change gears and move forward or backward. Because it reduces friction, the transmission fluid also controls the temperature within your transmission and will protect the metal surfaces from excessive wear and tear. Having the proper amount of transmission fluid added to your transmission will also increase the rotational speed of your engine and condition the gaskets as well. Having the proper amount of fluid inside your transmission is not something to mess around with.

How do I know if I have too much transmission fluid?

There are many symptoms of an overfilled transmission that you can look for. Some are easy to spot and others may require a little more time and understanding if you hope to catch the problem early on. If you're not sure about how much is too much, here are a few clues to look for.

  • Is your engine overheating? Ideally, your engine should run somewhere between 195 degrees and 220 degrees. Simply put, the needle should rest somewhere near the center of the gauge when driving. If your engine is running hotter, that could be a clue that too much transmission fluid is reducing lubrication within the crankshaft.
  • Are there transmission fluid leaks? Look for puddles pools or drips underneath the transmission. Is there leakage around the seals? If you've got leaks, you've either got too much fluid or you've got a more serious problem. Either way, you should have an expert check out your transmission closely to determine the source of the leak.
  • Are you having difficulty shifting? If you drive a manual transmission vehicle, you should have no problem determining this. Difficulty shifting could be a symptom of foamy transmission fluid, something caused when excessing fluid and air mix together.

What happens if my transmission fluid becomes foamy?

Transmission fluid will become foamy if there is too much fluid. Excessive fluid prohibits proper lubrication and cooling and slows the rotating crankshaft, similar to the effect of running through water. When the air above mixes with the high levels of fluid, it creates a foamy substance that saturates the transmission. This can lead to:

  • Part pitting
  • Poor shifting
  • High internal temperatures
  • Seal failure.

Note: if your engine and transmission seals begin to fail, this may mean that your transmission must be rebuilt.

If discovered too late, the eventual effects of putting too much transmission fluid into your vehicle can end up costing you hundreds or thousands of dollars in repair bills, and headaches as you wait for your transmission to be rebuilt. If you're not sure how much transmission fluid your car has, simply locate the transmission dipstick and pull it out while your vehicle is on and in Park. Just watch out because the transmission fluid could be extremely hot if your engine has been running for a significant period of time. Use a rag to clean it off and then stick it back into the transmission dipstick tube before pulling it back out again. Make sure the fluid goes all the way up to the FILL line. Be sure NOT to let the fluid go over that line.

If you aren't sure if you've got too much or too little transmission fluid, or what to do if you do have too much fluid inside the safest choice is to take it a professional mechanic who specializes in transmission repair. He or she will help get your levels right where they ought to be so you can be on your way.

At Express Transmissions, we have a longstanding reputation of being one of Toledo's top transmission repair shops in the region. Our experts can help identify exactly what's wrong with your transmission and find the best solutions to the problem quickly, efficiently and honestly. We know that not every transmission repair service is the same, and we would like to prove to you why we are the best. Contact us today to discover what quality automotive repair service should be.