Why Is There Transmission Fluid Leaking From the Bellhousing?

<Transmission Fluid Leak, transmission fluid leaking from the bellhousingTransmission fluid leaking from the bellhousing of your transmission means you’ve got a leak somewhere on the front of your transmission.  Unfortunately there area few places the fluid could be coming from and they are all pretty difficult to inspect.

The first step in diagnosing any transmission fluid leak from the front of your transmission is to see if your transmission has an inspection cover.  Most bellhousings do not go all the way around. They are sometimes split in half where the engine block meets the oil pan or have a cover at the bottom or top where you can remove a small plate and peek inside the bell housing.  Worst case scenario, you should at least be able to remove the start to get a peek at the flywheel.

Inspecting the flywheel, flex plate, clutch plate or torque converter is the best way to tell where your transmission fluid leak from the bellhousing is actually coming from.

Where is your transmission fluid leaking from the bellhousing coming from?

  • The torque converter
  • The transmission fluid pump seal
  • Transmission cooler lines
  • Bearing retainer plate
  • It’s not transmission fluid?!?

Once you’ve popped the inspection cover off look at the flexplate or flywheel.  If it’s got fluid dripping off the transmission side then you’ve got a transmission fluid pump seal leak if you’ve got an automatic transmission or a transmission front seal leak.  If there is no fluid on the flexplate or flywheel then you’ve got a bearing retainer plate leak in a manual transmission or a transmission cooler leak on an automatic transmission.

In an automatic transmission if the whole torque converter is covered in fluid, then chances are your torque converter has sprung a leak.  In any of these cases if the hard part repair doesn’t make sense for your vehicle or your budget, consider using BlueDevil Transmission Sealer to stop your leak guaranteed!

But what if your leak isn’t actually a transmission fluid leak?  Manual transmission fluid looks a lot like engine oil or clutch fluid.  If you’ve got a manual transmission check for a rear main seal leak or a leak in your clutch slave cylinder before you start looking for transmission leaks.

You can pick up BlueDevil Transmission Sealer at one of your local auto parts stores like:

  • AutoZone
  • Advance Auto Parts
  • CarQuest Auto Parts
  • NAPA Auto Parts
  • O’Reilly Auto Parts
  • Pep Boys
  • Canadian Tire
  • Walmart

14 responses to “Why Is There Transmission Fluid Leaking From the Bellhousing?

    1. Alfreemon-

      Thank you for asking about your Mercedes Benz E320. The BlueDevil Oil Stop Leak would be to seal the kind of leak you’ve described. You will add one oz. of the product per quart of fluid in the system, and should expect to start seeing results after 100-200 miles of driving.

      Thank you!


  1. Thank you for the article. 2008 62te leak showing at the inspection plate. Seems to leak cold or hot. Just had the pans off for a while. Working around my injury. Got put back together and now this leak.

    1. Larry,

      Thanks for your question about your transmission leak. Usually, leaks from the inspection plate come from the front seal in your transmission. These leaks happen most often either from age or from the vehicle sitting for a long time. You can try BlueDevil Transmission Sealer or you can remove your transmission to get a look at that seal behind the torque converter to see if it is indeed leaking and to replace it.

      Thanks again for your question!
      -BD Auto Pro

  2. I have a 01 lexus gs300 v6.2jz trans. I pulled tranny and replaced the torque converter refurbished. I replaced the front seal.i flushed the system new filter and pan gasket. And it’s a steady stream of trans fluid with vehicle started and in drive. Its killing me cause I’ve had several different inputs on it. Thanks in advance.

    1. Mike-

      Based on your description, this could be an issue where one of the seals isn’t on tight enough or even perhaps a loose hose connection. If you are able to pinpoint the location of the leak, you should be able to go from there. If not, you may want to bring the vehicle to a transmission specialist for inspection.

      Thank you!


    1. Jason-

      The BlueDevil Transmission Sealer is intended to treat leaks coming from rubber seals/gaskets. If the leak is coming from one of those rubbers, you would be a good candidate for the product.

      Thank you!


  3. Hey my nissan quest 07 was sitting for about two years before I got it I just bought it 2 weeks ago we had to replace the alternator and when we change it from gear to gear it knocks depending on the way we are sitting we where on the road going up a hill the other day and my brother was tryna change from low to drive to help the shift from knocking so bad and it shut off we put it in park and crank we got to the store and its was leaking badly like a consistant line of transmission fluid can you please tell me what that could be and what choices do I have to fix it

    1. Dalton-

      Thank you for asking about your Nissan Quest. More than likely, the knocking noise you were hearing would be attributed to the system being too low on transmission fluid. Based on your description, with the vehicle sitting for that long, the rubber seals/gaskets may have shrunken or become brittle from not getting the proper lubrication. They may have deteriorated to the point where the only way to fix the issue would be to have said seals/gaskets replaced. Your best bet may be to bring the vehicle to a transmission specialist for inspection.

      Thank you!


  4. My car started leaking fluid after a drive on the highway it was smoking from the rear, it didn’t run hot but it’s leaking pretty bad now, and wasn’t leaking before will devil help?

    1. Marco-

      BlueDevil Transmission Sealer will treat leaks that are seeping or lightly dripping. As long as you are not losing fluid too quickly, you would be a good candidate for the product. You should expect to start seeing results after 100-200 miles of driving.

      Thank you!


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