Rear Main Seal and Oil Pump

Tonight I installed a new rear main seal and oil pump cover gasket.

To install the new rear main seal, I lubricated the seal with a bit of oil and then set it in place.

The 3D printed seal install tool was then put in place.   Here I have the flat side out just so that I can demonstrate installing the seal that will sit proud by 2mm.  The old flywheel bolts were first hand tightened and then tightened using a socket wrench.  I tightened each bolt in turn 1/4 turn until the plastic bottomed out on the case.   Here you can see I installed washers, but honestly, there’s so little pressure, you don’t really need them.    You also don’t need to tighten in a cross pattern.

Here’s the seal installed with the same height above the case as the old style seal that I pulled out.

I turned the tool over so the flat side was against the seal and tightened again until the plastic was against the case.  Now the seal is flush.

Before installing the flywheel I wanted to replace the oil pump cover gasket.  While I had the cover off I measured the outer rotor to case clearance at 0.005″ The spec is 0.005″ to 0.008″, so that’s good.  I also attempted to measure the inner rotor tip clearance, but the thinnest gauge I have, which is .0015″ wouldn’t fit.  So the clearance is less than .0015″.  This spec is .001 to .003, so again all is good.

For reference, the cover installs with the indentations oriented towards the bottom as shown.  This picture was taken just after the cover was removed and before the seal was replaced.

6 thoughts on “Rear Main Seal and Oil Pump”

  1. Thanks for allowing us to download the STL file for the main seal installer for 3D printing !
    I have one question: are the five holes in the installer 10 or 11 mm in diameter ? 10 mm = older type heavy flywheel, 11 mm newer type light flywheel.

    Best regards,

    Dirk Kooiker

    1. My sincerest apologies for the delay in approving your comment. I missed it with all of the spam comments that I receive.

      It’s probably too late to be useful to you, but to answer your question, the holes in the installer are about 11.5mm.

      Bob

Leave a Reply