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Gmc Pm151 Engine Crankshaft Seal Kits

Gmc Pm151 Engine crankshaft seal kits

Starting at low prices, AutoBuffy carries multiple engine crankshaft seal kits from top OE-quality brands for the Gmc Pm151. A crankshaft seal kit contains the front and/or rear lip seals that keep oil from leaking past the crankshaft ends. When these seals fail, oil escapes onto belts, the flywheel, or the ground — leading to low oil levels, component damage, and costly secondary repairs if ignored.

Signs your Gmc Pm151 needs a new engine crankshaft seal kit

  • Oil puddle or drips directly beneath the front or rear of the engine after the vehicle sits overnight
  • Visible oil film or wet residue coating the harmonic balancer, timing cover, or flexplate/flywheel area
  • Serpentine belt, timing belt, or accessory drive belt shows oil saturation or glazing, causing squealing or slipping
  • Burning oil smell from the engine bay caused by oil dripping onto hot exhaust components near the seal location
  • Unexplained drop in oil level between changes with no visible external leak found elsewhere on the engine
  • Oil-soaked rear main area combined with transmission contamination or clutch slippage on manual-transmission vehicles

Which engine crankshaft seal kit should you buy for your Gmc Pm151?

The most important decisions are position (front seal, rear main seal, or a combined kit covering both) and seal material, since rubber compound and lip design determine how well the seal conforms to the crankshaft journal and holds up to heat cycles. OEM-spec kits that include the correct seal for your specific crank diameter and surface finish will outlast universal-fit alternatives. Some kits also add a wear sleeve or speedi-sleeve to restore a grooved crankshaft journal, which is worth choosing if your crank shows visible wear.

Front crankshaft seal only
Best for
Isolated front leak — oil on timing cover or harmonic balancer with a dry rear main
What you get
Single lip seal sized for the front journal; often includes a new gasket for the timing cover or front cover
Rear main seal only
Best for
Isolated rear leak — oil on flywheel, flexplate, or bellhousing with a dry front cover
What you get
Single or two-piece lip seal for the rear journal; may include a retainer gasket or seal housing O-ring
Complete front + rear kit
Best for
High-mileage engines or preventive replacement during a timing belt, water pump, or clutch job
What you get
Both seals in one purchase, often with cover gaskets and O-rings; saves labor by addressing all crank seals at once
Kit with wear sleeve (speedi-sleeve)
Best for
Engines with a visibly grooved or scored crankshaft journal surface that caused the original seal to fail prematurely
What you get
Seal plus a thin stainless sleeve that presses over the worn journal and gives the new lip seal a fresh sealing surface

Replacing an engine crankshaft seal kit on a Gmc Pm151

Advanced⏱ 2–6 hours depending on seal positionHarmonic balancer pullerSeal driver or seal installation tool sized for the crankshaft journalTransmission jack (for rear main seal access)Torque wrenchPry bar and plastic trim tools for seal removal

Front seal replacement requires removing the harmonic balancer and timing or front cover to access the seal, then carefully driving the new seal in flush and square using a proper seal driver — never hammer the seal directly. Rear main seal replacement on most engines requires transmission removal, flywheel or flexplate removal, and sometimes a seal retainer, so plan for a longer job and consult a service manual for your specific Pm151. Always lightly lubricate the seal lip with clean engine oil before installation and ensure the crankshaft journal surface is clean and free of scoring before pressing the new seal into place.

Frequently asked questions

How much does it cost to replace engine crankshaft seal kits on a Gmc Pm151?
Parts start at low prices for the Gmc Pm151 at AutoBuffy. Total cost depends heavily on which seal needs replacement: a front seal is usually a shorter job, while a rear main seal often requires removing the transmission or flexplate, making labor the dominant expense. Doing it yourself significantly cuts overall cost.
Can I drive my Gmc Pm151 with a leaking crankshaft seal?
You can drive short distances, but it is not advisable. A leaking crankshaft seal causes progressive oil loss that can lead to low oil pressure and engine damage. Oil contacting a belt or clutch disc creates an immediate safety and reliability risk. Address the leak as soon as practical to avoid compounding repairs.
How long do crankshaft seals last on a Gmc Pm151?
Crankshaft seals are designed to last the life of the engine under normal conditions, but rubber compounds harden and shrink with age and heat cycles. In practice, many seals begin leaking somewhere in the range of 100,000–150,000 miles or after 10–15 years, whichever comes first — earlier if the engine runs hot or oil changes are infrequent.
Is a front crankshaft seal replacement easier than a rear main seal on a Gmc Pm151?
Yes, generally by a wide margin. The front seal is accessible once the harmonic balancer and timing cover are removed — typically a moderate DIY job. The rear main seal usually requires dropping the transmission and removing the flywheel or flexplate, making it an advanced job that many owners prefer to leave to a shop.
What causes crankshaft seals to fail on a Gmc Pm151?
The most common causes are age-related rubber hardening, a worn or grooved crankshaft journal that destroys the seal lip, excessive crankcase pressure from a clogged PCV system forcing oil past the seal, and improper installation that damaged the seal lip or left it misaligned. Fixing the root cause — especially PCV issues — is essential before installing a new seal.
Should I replace both front and rear crankshaft seals at the same time on my Gmc Pm151?
If one seal has failed due to age or mileage, the other is likely made of the same rubber compound and is equally degraded. Replacing both while the engine is already partially disassembled costs little in additional parts and avoids repeating significant labor shortly after. A complete kit covering both positions is the practical choice on high-mileage engines.

More parts for your Gmc Pm151

Engine Timing Camshaft SprocketVoltage RegulatorGenerator Brush SpringIgnition Lock CylinderIgnition Conversion KitDistributor CapAutomatic Transmission Oil Cooler HoseEngine Timing Set

Engine crankshaft seal kits for other Gmc models

Gmc R3500Gmc C15/C1500 PickupGmc C25/C2500 SuburbanGmc SafariGmc C25/C2500 PickupGmc C1500