SKF
Engine Shaft Seals
SKF engine shaft seals are designed to seal the rotating crankshaft and camshaft exits from the engine block and cylinder head. The front crankshaft seal operates at high speed behind the auxiliary drive pulley, withstanding belt dust and engine bay heat. The rear crankshaft seal (rear main seal) is a larger, critical seal that often integrates a PTFE lip, FKM body, and an integral wear sleeve, and may incorporate a magnetic encoder ring for the crankshaft position sensor. These seals retain pressurised oil and exclude clutch dust or external contamination. SKF uses advanced simulation to optimise lip contact pressure and hydrodynamic features for zero leakage over the engine's life. Engine shaft seals are validated under extreme thermal cycling, oil mist, and shaft dynamics to ensure they meet global OEM durability standards.
Send an Enquiry
We'll get back to you on WhatsApp.
Trusted by Industry Leaders
Front and Rear Crankshaft Cassette Seals
PTFE lip, integral wear sleeve, and dust lip in one module.
High‑Speed Compatibility
Designed for modern engines with high‑RPM variable valve timing.
PTFE Lip for Low Friction
Reduces parasitic loss, aiding fuel economy.
Magnetic Encoder Integration (RMS)
Rear main seal also serves as crankshaft position sensor.
Robust FKM Bodies
Withstand under‑bonnet temperature extremes and hot oil.
Misalignment Tolerance
Lip flexibly follows crankcase bore and crankshaft deflection.
The Evolution from Rope Packing to Cassette PTFE Seals
Early engines used asbestos rope packing as a rear main seal, which leaked and required periodic adjustment. The modern SKF cassette PTFE rear main seal is a zero‑leakage, install‑and‑forget component. Its PTFE lip wears at an almost imperceptible rate, sealing the crankcase for the engine’s entire service life.
The Consequence of a Rear Main Seal Leak
A leaking RMS drips oil onto the flywheel and clutch, causing clutch slippage and expensive replacement. SKF’s rigorous dynamic testing of every seal design prevents high‑mileage leaks, protecting the vehicle’s drivetrain reliability and reputation.