Leaking Transmission Fluid

Transmission Fluid LeakLeaking Transmission fluid can often be more difficult to identify than other types of leaks.  If you have a rear, 4 wheel or all-wheel drive vehicle, the leak point is often right in the middle of your vehicle making it something you probably won’t notice unless you’re regularly crawling under your vehicle.  If you keep up with weekly, monthly and yearly maintenance checks on your vehicle, you just might catch a transmission leak before it becomes a big deal.  For more information on what sort of things you should regularly be checking on your vehicle, check out our series on routine maintenance.

Most transmissions are fairly well sealed and usually don’t start to leak until they have quite a few miles on them, or have not been regularly maintained.  Most people think of changing transmission fluid to help preserve the gears, bands and clutches in their transmission.  The reality is fresh transmission fluid can also help preserve the seals and gaskets in your transmission as well.  The “dirt” in your transmission fluid is actually more wear products that actual dirt or sand.  Unlike your engine, your transmission is a closed system meaning it is very difficult for dirt or dust to get in.  That means the suspended particles in your transmission fluid that turn it brown or black are mostly tinny metal shavings that are worn off gears and bearings in your transmission.  These tinny metal shavings get pumped around your transmission in the fluid and can act like liquid sand paper on the inside of the seals and gaskets causing them to wear out and fail prematurely.  To keep this from happening, make sure you change your transmission fluid at the factory recommended intervals.

The other main reason that your vehicle has started leaking transmission fluid is that the bearing inside have become worn out.  The shafts that go through the seals in your transmission are held in place by bearings so they don’t move in, out, up or down but still allow the shaft to spin freely.  As the bearings become worn due to use, the shaft can start to sag down pulling on the seal and leaving a small space at the top where transmission fluid can leak out.

As you’re checking for transmission fluid leaks the first place to check where the driveshaft or axles exit the transmission.  This seal is the most likely to leak, since it is open to road grime and dirt on one side and transmission fluid on the other.  The other seal that is most likely to leak is where the input shaft goes into the transmission.  This seal will be hidden by the clutch or torque converter and ultimately the bell housing so it can be extremely difficult to inspect without removing the transmission.  Usually if this seal is leaking you will find transmission fluid dripping from where the bell housing bolts to the engine block.  Even though it’s unlikely, it is possible for your transmission to be leaking from one of the seals where the case is bolted together.

All of these seals or gaskets can be extremely difficult to get to without removing the transmission from your vehicle.  That includes disconnected all the axles and drive shafts, removing the transfer case if its 4 wheel drive, removing all the shift linkages, sensors and wiring and unbolting it from the engine.  Once you’ve done all that, which can be hours work, it is also extremely heavy and difficult to maneuver.

Leaking Transmission FluidA much better way of stopping your leaking transmission fluid is to simply use BlueDevil Transmission Sealer.  BlueDevil Transmission Sealer is a completely safe additive that you add to your transmission fluid to stop your leak.  BlueDevil Transmission Sealer is designed to restore the seals and gaskets in your transmission to their original shape and size which can stop your leak permanently.

BlueDevil Transmission Sealer

You can purchase BlueDevil Transmission Sealer directly from BlueDevil here: Transmission Sealer

You can also purchase BlueDevil Transmission Sealer at any of our partnering local auto parts stores like:

  • AutoZone
  • Advance Auto Parts
  • Bennett Auto Supply
  • CarQuest Auto parts
  • NAPA Auto Parts
  • O’Reilly Auto Parts
  • Pep Boys
  • Fast Track
  • Bumper to Bumper Auto Parts Specialists
  • S&E Quick Lube Distributer
  • DYK Automotive

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transmission_fluid_leak.jpg – By Plik – Licesned by Creative Commons Share Alike 3.0 – Original Link
tTransmission_fill.jpg  – By Paul79uf – Licesned by Creative Commons Share Alike 3.0 Via Flikr – Original Link

 

2 responses to “Leaking Transmission Fluid

  1. Just put a recon torque converter. After putting some oil in the car have found a pool of oil under the car. Looks like its come from around the bell housing. Have I done something wrong or is something else wrong. Any ideas.

    1. Justin,

      Thanks for your question about your torque converter. Based on your question, we’re assuming that by “oil” you’re talking about transmission fluid. If your car is leaking engine oil after putting a new torque converter on, then you probably damaged your rear main seal during installation. If your car is leaking transmission fluid after installing a new torque converter then you may have damaged the front seals on your transmission or incorrectly installed the torque converter. If you do end up with a pool of transmission fluid without even running your car, we’d recommend pulling things apart and finding your leak as it will likely be a fast leak if you start your engine.

      Thanks again for your question!
      -BD Auto Pro

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