Rear Crankshaft Seal Leak

rear crankshaft sealYour engine is full of all sorts of different seals and gaskets.  Your engine is designed to run best while it is well lubricated with engine oil.  This oil is stored at the bottom of your engine in the oil pan.  From there it is suctioned by the oil pump, pressurized, sent through the oil filter then on to do its job lubricating the engine components.  For a more in-depth explanation of the route the oil takes in your engine, check out this article about Where Engine Oil Goes.  Understanding the long route the oil in your car takes makes accepting that your vehicle has an oil leak a little easier.  The seals and gaskets in your motor have a big job keeping the hot slippery oil contained as it travels around your engine.  The rear crankshaft seal is no exception to this as it has one of the most difficult jobs in your engine.  Where the rear crankshaft seal is an exception, is that it is the most difficult seal to change in your engine.

Many oil leaks are extremely simple fixes and can be very inexpensive, or even maintenance items that can be easily done yourself in your driveway with a small toolkit and an hour or so.  Leaking gaskets like a leaky valve cover gasket, valley pan gasket, or timing chain cover are on the top or front of your engine so they’re often easily accessible.  These components also aren’t complicated or difficult to remove so the time, and therefore cost, to replace them is relatively small.

There are also more challenging oil leaks to repair on your vehicle.  Leaks like a camshaft seal leak or oil pan gasket leak on some cars can take a little more expertise and time to replace.  These leaks often take a little more skill to replace as they may require the removal of some other accessories or peripheral equipment to access them.

On the other hand, a rear crankshaft seal is the most challenging seal in your engine to replace.  This is because at the very least it will require removing the transmission from your vehicle and at most will require removing the entire engine.  Removing either the engine, the transmission, or both from your vehicle are some of the most complicated maintenance procedures you can perform on your car.  Removing such equipment requires a significant amount of knowledge about the construction of your car but will also require lots a few specialty tools including lifts and hoist and specialty wrenches to reach some of the hidden bolts and nuts holding things together.  Of course, once you’ve got the engine and transmission out you still need to skills to replace the rear crankshaft seal.

Many oil leaks in your engine can be inexpensively fixed by simply replacing the seal or gasket.  Since the rear crankshaft seal is not one of those that is simple to replace, it can be much more cost effective to simply repair that seal allowing the original seal to stay in place while still stopping your leak.  The easiest way to repair your rear crankshaft seal is to simply add BlueDevil Rear Main Sealer to your engine oil and continue to drive your vehicle like usual.  After approximately 2 days of drive time, BlueDevil Rear Main Sealer will restore your rear crankshaft seal to its original size and shape sealing the leak and keeping your car safe.

For more information about BlueDevil Rear Main Sealer click on the banner below!
BlueDevil Rear Main Sealer


You can also find BlueDevil Rear Main 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
  • Fisher Auto Parts stores
  • Auto Plus Auto Parts stores
  • Hovis Auto & Truck Supply stores
  • Salvo Auto Parts
  • Advantage Auto Stores
  • Genuine Auto Parts stores
  • Bond Auto Parts stores
  • Tidewater Fleet Supply
  • Bumper to Bumper Auto Parts
  • Any Part Auto Parts
  • Consumer Auto Parts


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12 responses to “Rear Crankshaft Seal Leak

    1. William-

      We do not currently have any distributors in Australia. However, you may purchase products directly through our website, Simply fill in the billing and shipping fields and the order total would be calculated at checkout.

      Feel free to contact us at 888-863-0426 with any further questions.

      Thank you!


    1. Josh-

      Yes, the system would be filled almost to capacity with oil, leaving just enough room for the recommended amount of the product. Feel free to contact our technical support line at 888-863-0426 with any other questions.

      Thank you!


    1. Allison-

      Typically with the product, you should expect to see results after approximately 100-200 miles of driving. Have you noticed any improvement? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.

      Thank you!


  1. I added the oil stop leak to my vehicle for crankshaft seal leak. My question is will this stop that leak or should I have used the rear main seal. I didnt realize when I bought it that the rear main seal was designed for crankshaft seal leaks.

    1. Nate-

      The BlueDevil Oil Stop Leak is the appropriate product to treat a crankshaft seal leak. You should expect to see results after approximately 100-200 miles of driving.

      Thank you!


  2. Hi I have a Kia Amanti and I have a rear crankshaft leak on the endcap. The leak is not where the belt is but the other end. I am in the process of replacing the valve cover gaskets and while the car is still siting in my driveway it is leaking oil slowly at the cap. Next will be an oil change flush but when that is done and get fresh oil how much of Daredevil rear crankshaft product can I use? And is this a guarantee that it will seal?

    1. Brinda-

      Thank you for asking about your Kia Amanti. One bottle (8 oz.) of the BlueDevil Oil Stop Leak will treat 4-6 quarts of oil. The product carries a money-back guarantee, so if it is unable to seal for whatever reason, you can simply contact our technical support line at 888-863-0426 for further assistance.

      Thank you!


  3. I have a front crankshaft leak on a 4,3l mercruiser. What is the product I should use?

    1. Patrick-

      The BlueDevil Oil Stop Leak would be the appropriate product to use for your leaking crankshaft seal. Feel free to contact our technical support line at 888-863-0426 with any other questions.

      Thank you!


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