Oldsmobile 403 Viton 2pc Rear Main Seal (Not Pontiac)

SKU: BOP-RMS03

Oldsmobile 403 Viton 2-piece rear main seal. NOT for Pontiac engines — Pontiac uses BOP-RMS01/RMS18 (3.00" main) or BOP-RMS02/RMS19 (3.25" main).

Availability:

Pricing: $53.95

Description

Oldsmobile 403 only — NOT for Pontiac

Fits: Oldsmobile 403.
Pontiac engine? 3.00" main (326-400, 265/301): BOP-RMS01 (2-pc) or BOP-RMS18 (1-pc). 3.25" main (421/428/455): BOP-RMS02 (2-pc) or BOP-RMS19 (1-pc).
2-piece Viton seal. BOP's RMS01/RMS02 instruction sheet applies to this seal as a general reference only.

Factory-type rope seals lost their asbestos content, and leakage became common. This Viton 2-piece seal replaces the rope seal and installs quickly.

Installation Notes

Dry fit the seal in the block and cap (no sealer, no crank) and look through the bore — the ends must meet with no gaps or distortion, and the seal must not flex or bulge when the cap is installed. If it does, trim slightly with a sharp utility knife. Fitment before installation is what makes it seal; too tight means more drag.
Put a thin film of high-temp silicone on the seal ends only. Do not coat the back of the seal, the groove or the seal cavities.
Lightly oil the lips before final assembly.

Not sure which one you need? Ask a tech question or call 866-762-7527 before you order.

Butler Tech Library

Viton or Rubber Rear Main Seal?

What the Viton seal does differently, when it's worth it, and how to install one so it actually stays dry.