• Replacing Front Oil Seal on a Crusader 270

    This project can be difficult just by the fact that my boat has v-drives and the engines sit backwards in the boat. To ease the process I have several egg crate camping mattresses that make the job a bit more comfortable.

    Also keep in mind with counter rotating engines the oil seals will be unique to each engine, make sure you order the correct ones.


    To do this job you will need the normal compliment of tools and a few others as shown in the photograph below. You will definitely need a puller like the one shown below, the harmonic damper has a rubberized ring within it that the jaw type pullers may destroy. The PVC pipe is 2 inch diameter and approximately 3 inches long. This is used to help install the new oil seal.

    Attachment 533

    To gain access to the seals you will have to lay across the top of the engines. The seals are located behind the harmonic damper and pulley assembly below the water pump.

    Attachment 534

    Begin by loosening the three bolts holding the crankshaft pulley assembly to the harmonic damper. Then loosen the bolt in the center that fastens the whole assembly to the crankshaft.
    Attachment 535

    Once these are broken loose then you can remove the belts. Loosen both the alternator mounting bolt and the tensioner bolt, then remove the belt. The belt cannot be removed completely until the water pump belt is removed.
    Attachment 536

    The raw water pump is located slightly below and to the left of the crankshaft.
    Attachment 537

    Loosen the two mounting bolts for the raw water pump. They are located on the bottom of the water pump mounting bracket. In this picture you can see the mounting bracket after the pump has been removed. This is a good time to replace the impeller since removing the water pump will give you more room to work. Click here for an article describing this process.
    Attachment 538

    Once those two bolts are loosened you can slide the pump laterally and remove the belt. Now continue to remove the bolts in the crankshaft pulley assembly and remove both pulleys.
    Attachment 540

    2nd Pulley
    Attachment 541

    Now install the puller on the harmonic damper and begin slowly removing it. Ensure that you get the bolts from the puller threaded at least 3/8 inch into the harmonic damper. You may have to tap lightly on the harmonic damper to get it to break loose.
    Attachment 542

    Now with the harmonic damper removed you can easily see the oil seal.
    Attachment 544

    Use caution in removing the old oil seal, the timing chain cover that the seal is mounted in is very easy to bend. There are several methods that may work if the seal is stuck. You can use a screwdriver to pry the seal out. If you can get the edge of the seal out enough to get a screwdriver against it, you can collapse the seal as I did in this removal. For some stubborn seals use a small drill bit to drill a tiny hold in the face of it. Then thread a screw into the face and use that to pull it out. In the picture below I am using a screwdriver and small hammer to collapse the seal. I am tapping toward the crankshaft, not in.
    Attachment 545

    This picture shows the removed seal and you can see how I collapsed the side.
    Attachment 547

    This view shows the timing chain cover with the seal removed.
    Attachment 546

    Installation of the new seal is pretty straight forward, ensure the timing chain cover and seal guide are clean, coat the outside edge of the seal with a light coating of grease and place in the timing chain cover. Using a hammer lightly tap around the edges to begin seating the seal. The PVC pipe can be used to help seat the seal as shown in the photo below.
    Attachment 548

    Once the seal is in place, ensure the harmonic damper has been cleaned up. The back side of the harmonic damper slides into the oil seal, it is important that this area be cleaned and perfectly smooth or the new seal could leak. Scotch brite pads on an air sander work really well to accomplish this however 200 grit or finer sandpaper can be used. Once the area is cleaned up coat it with a light layer of grease. The picture below is of a stock harmonic damper but shows the area that needs to be clean.
    Attachment 939

    Now slide the harmonic damper on the crankshaft and align with the key in the shaft.
    Attachment 551

    Now install the other two pulleys onto the harmonic damper, partially thread the remaining three bolts into the damper, but do not tighten them. Insert the center bolt through the pulley assembly into the end of the crankshaft. We will use this bolt to press the harmonic damper onto the crankshaft. Slowly begin tightening the center bolt to begin pulling the damper onto the crankshaft. As the damper slides onto the crankshaft and begins to penetrate the oil seal rotate the crankshaft a few times as you go to ensure the damper slides neatly into the seal. This process may take some time and occasionally tapping lightly with a hammer may help. Rotate the crankshaft approximately 30 degrees and tap again lightly, then tighten some more. Repeat this process as necessary.
    Attachment 552

    Once the harmonic damper is fully seated, torque it to the manufacturers specs, for this Crusader 270 the recommended torque is 70 ft/lbs.

    Now align the pulleys and tighten the bolts. Install the belts and adjust as necessary and you are done.
    Insecto likes this.


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