How Hard is it to Replace a Rear Main Seal?

Its’ Hard.

Leaking Rear MainReplacing a rear main seal is time consuming, requires special knowledge of your vehicle and the use of special tools if you are going to do it correctly and without placing you or your vehicle in danger.

“You have a leak from your rear main seal” is one of those phrases that we all hope to never hear from your mechanic.  Usually, that is one of those phrases that makes you cringe because you know you have a hard decision to make.  Since it is such a difficult repair, it’s usually not something you can do yourself and your mechanic has to charge a lot for.  Replacing a rear main seal can be so expensive the cost to replace it may be more than you have to spend, or even more than your vehicle is worth.

When faced with a high dollar repair on an older vehicle it can be difficult to decide if it’s worth dumping more money into an older vehicle that doesn’t have much value.  There are a few things to consider when making this decision.

  • What is your vehicle worth in its current condition?
  • What is the cost of this repair?
  • Are there other major repairs need?
  • What is the vehicle worth in good working condition?

You may be surprised how much your vehicle is worth in its unrepaired condition.  Today, there is so much information available on the internet on how to repair many vehicles and the ability to order almost any replacement part either OEM or aftermarket, new or used from a wide variety of trading websites, Ebay, and parts wholesalers. This means that there are more and more people willing to pay top dollar for cars needing major repairs.

Car For SaleThe difficult part can be finding out how much someone is willing to pay for your broken car.  The best way is to check local listings and see what other vehicles in need of repair are selling for.  Often these can be listed as “mechanic’s specials”.  You might check your local newspaper classifieds, Craigslist or Autotrader.  If you have the time, you can also try posting an add for your vehicle in its current condition and see what offers you get for it.  If your broken vehicle’s value plus the needed repair cost is more than what the vehicle is worth in good condition, it may be time to think about selling it.  The good news is a vehicle with a leaking rear main seal is usually still able to be taken at least on a test drive which will help with the resale value.

Before you jump on Craigslist and put up a new add you should consider if there are any alternative solutions to a costly repair.  Most of the oil leaks your engine will develop are due to old or worn out gaskets and seals.  These seals over time can become shrunken or cracked and brittle do to old age, infrequent use or even regular intended usage.  Instead of replacing these old seals and gaskets, first try restoring the ones currently in your engine.  BlueDevil has a full line of oil stop leaks products designed to repair and restore the seals in your engine and is guaranteed to stop seeping or dripping oil leaks.  BlueDevil products will not clog or harm your engine in anyway and can stay mixed in your oil until your next oil change.

BlueDevil Rear Main Sealer

For your leaky rear main seal, use BlueDevil Rear Main Sealer available here
or at your favorite auto parts stores like:

  • Bennett Auto Supply
  • Prime Automotive Warehouse
  • Pep Boys
  • CarQuest Auto Parts
  • AutoZone
  • Advance Auto Parts
  • O’Reilly Auto Parts
  • NAPA

Pictures courtesy of: and

30 responses to “How Hard is it to Replace a Rear Main Seal?

    1. It is not necessary however you must leave the treated oil in the system for at least 200 miles of driving (not consistent) after the installation of the product.

      If you have any other questions, feel free to call our tech line at 1.888.863.0426.

    1. Daphne-

      Yes, BlueDevil Rear Main Sealer is compatible and safe to use in your Yukon. Once the product is added you can expect to start seeing results after about 100 miles of driving.

      Thank you!


    1. Caleb-

      Thank you for asking about your Jeep Grand Cherokee. Depending on where you are located, a rear main seal replacement can cost anywhere from $650-$850. It is a very labor intensive job, as usually the parts will only cost around $40-$50.

      Thank you!


    1. Joel-

      The BlueDevil Rear Main Sealer is compatible in your VW. As long as you are not losing oil too quickly, you would be a good candidate for the product. You should expect to see results after about 100-200 miles of driving. Feel free to contact our technical support line at 888-863-0426 with any other questions.

      Thank you!


  1. Used your product on my 2002 Suburban and it worked great for awhile. A few months later it is leaking again. does this need to be added more than once?

    1. J-

      Thank you for asking about your Chevy Suburban. Typically, you should only need to add the product once. Once the product seals, it would create a permanent seal. Please contact our technical support line at 888-863-0426 so that we can get a better understanding of the vehicle’s condition and be able to make any appropriate recommendations.

      Thank you!


  2. I have Chevrolet Spark LS 0.8 2009 and encountered with its Main Oil Seal leaking. Could u please tell me if I can purchase Blue Davil Rear Main Sealer in Pakistan and from where?

  3. Read your article, was informed that I may have/appears to be an engine rear seal leak. Vehicle is a 2008 Ford Edge AWD, i assume your product would work/is compatible??

  4. I used the rear main seal stop leak and the leak is improved about 90%…is it ok to add another bottle or do I need to do another oil change as well?

    1. Carol-

      Based on your description, it would be okay to add another bottle of the BlueDevil Rear Main Sealer. You would not need to change the oil prior to re-adding the product, unless you are due for a change within the next 300 miles or so. Please contact our technical support team at 888-863-0426 so that we may assist you in receiving a replacement bottle.

      Thank you!


    1. Ruben-

      Yes, the BlueDevil Rear Main Sealer is safe and compatible to use on your Ford Ranger. You should expect to see results after about 100-200 miles of driving.

      Thank you!


    1. Lee-

      The BlueDevil Rear Main Sealer is only intended for rubber seals. Unfortunately, we do not manufacture a product intended for rope seals. A hard part repair may be your best option.

      Thank you!


    1. Camara-

      Thank you for asking about your Buick. The BlueDevil Rear Main Sealer is intended for leaks that are seeping or lightly dripping from the system. If you are losing oil at a rapid rate, unfortunately, it does not sound like a good candidate for the product. A hard part repair may be your best option.

      Thank you!


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