8:17 PM 3/18/2016 Crankshaft Rear Seal-d
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RUBBER REAR SEAL for Three Main Bearing Engine - CS-202D

The rear seal installation is in 5 steps spanning 5 web pages.
Click green arrow at bottom to follow pages in sequence.
    A - Modify rear plate
    B - Machine slip ring
    C - Modify Viton seal
    D - Modify bearing cap - (this page
    E - Assembly
    F - Can I buy it?
    G - Video Installation
    H - Follow-up notes

The last part to need just a little machining is the rear main bearing cap. This new seal will be catching the oil that sneaks past the original helical groove mechanical shaft seal. The oil trapped here must then have some way to drain back into the engine sump. If the oil were to remain trapped in the pocket around the crankshaft flange, the milling and thrashing about of the flywheel bolt heads would force the oil out past the new seal. Been there, done that, not a good condition.

The solution here is to drill a couple of small drain return holes near the bottom of the bearing cap. These holes will be positioned inside the perimiter of the new seal and as low as possible in the pocket. Drill two 5/32 inch diameter holes as shown, just above the cork seal channel, 11/16 inch each side of the centerline of the cap. At just over 1/4 inch deep these will break through into the cast oil return pocket.

rear cap - top view
Top View showing oil return pocket.
rear cap - rear view
Rear View showing new drilled drain holes.
rear cap - end view
End View.
rear cap - bottom view
Bottom View showing mounting stud holes.
rear cap - front view
Front View (inverted) showing original holes for oil draining.

Note: This is a rear main bearing cap from a 1600 engine. It does not have the screwed in down tube that was used on the 1500 engine, but instead uses the two large drilled drain holes seen here in the last view above. The two small drain holes we drill are still located the same.

rear cap installed
Rear cap installed (without crankshaft).
Note: When installing the cork seal, paper gasket and rear plate,
it is important not to obstruct the newly drilled drain holes.

rear cap installed - inside view with block inverted
Rear cap installed. Inside view with block inverted.
rear cap with drain holes rear cap with drain holes
New drain holes through bearing cap, with punch through hole.

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