The MGA With An Attitude
RUBBER REAR SEAL for Three Main Bearing Engine - CS-202A

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 - (this page)
    B - Machine slip ring.
    C - Modify Viton seal
    D - Modify bearing cap
    E - Assembly
    F - Can I buy it?
    G - Video Installation
    H - Follow-up notes


Finished seal installed and caulked

The process of installing a rear seal starts with some simple machining of the engine rear plate. Please ignore the oil spots on the backdrop paper, as there will be some of that in many of the following pictures. To allow space for the new seal you must enlarge the big hole in the center of the engine rear plate for more clearance around the crankshaft flange. And while you're at it, add four tapped holes for screws to hold the new seal in place.

The drawing below the pictures gives the dimensions for machining. Notice that the enlarged center hole cuts into the counterbores around three of the original bolt holes.

Rear plate before machining
Engine rear plate before machining.

Rear plate after machining
Engine rear plate after machining.

Front side of rear plate after machining
Front side of rear plate after machining.

The shallow slot at the bottom of the big bore is the original drain slot in the front of the plate to allow oil that has sneaked past the mechanical seal to drain out between the engine block and the rear plate before it gets back to the flywheel and clutch area. This was never fully effective, as there was nothing to keep the oil from going past the flange of the crankshaft that was positioned in that large center hole. During final assembly of the newly modified parts you will be plugging up that shallow slot with silicone sealant so no oil can escape from the engine.

Rear plate machining drawing
Rear plate machining dimensions
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