Seals

Seals: the small parts that keep oil where it belongs

Engine seals ride on rotating and reciprocating shafts to hold oil and coolant inside the engine and keep dirt out. A rear main seal wraps the back of the crankshaft; cam seals close off the ends of the camshafts; TGV and shaft seals handle intake and accessory shafts. When one hardens or splits, you get drips, low oil, and a mess on the bellhousing - which is why people replace them during a clutch job, a timing job, or any teardown where the shaft is already exposed. Fitting a fresh seal while you're in there is cheap insurance against pulling it all apart again.

What ThreePiece stocks

This category holds 47 seals and seal sets in stock right now, priced from $20 to $152 - the current range for what's on the shelf, not a fixed price. There are 17 brands in the mix. The largest counts come from TwinPower and Cometic Gasket, with Victor Reinz, ARB, Radium Engineering and Torque Solution close behind, plus FAST, S&S Cycle, All Balls Racing, Injector Dynamics, Gates, Vibrant and others. Coverage skews toward Harley-Davidson Big Twins and Sportsters, Subaru WRX and STI, Dodge Ram, Ford, Honda, Mitsubishi Evo, and a set of dirt bikes across model years from 1970 to 2023.

Concrete examples: the MAHLE Original rear main seal set at the top of the price range, the MAHLE Original Cummins rear main seal, the FAST LSXR intake manifold seal kit, the COBB Subaru EJ TGV shaft seal kit, the S&S Cycle left main bearing seal five-pack, and the Torque Solution WRX/STI valve cover cam seals.

How to choose

Start from the job. A single shaft seal fixes one leak point; a seal set or kit gives you every gasket and O-ring for a specific service so you're not chasing a second leak next weekend. Kits like the FAST LSXR and COBB TGV pieces are matched to an assembly, while a single rear main seal is right when only the crank seal is weeping. Buy to the exact application - seal diameters and shaft sizes are not interchangeable - and if you're already inside the engine, replace neighboring seals in the same area while access is easy.

What to order with it

Seals rarely go in alone. Pair them with gasket kits and head gaskets when you're opening the engine, and check bearings if a main or cam seal is worn. Fresh oil filters finish the job, and browse the wider Engine Components section for fittings and other parts.

Fitment and ordering

Twenty-two of these listings carry vehicle fitment data. Not sure which seal matches your engine? Call fitment help at 813-535-5801 or reach us through contact us. Every order ships free, and Affirm and Katapult financing is available at checkout.

Seals: the small parts that keep oil where it belongs

Engine seals ride on rotating and reciprocating shafts to hold oil and coolant inside the engine and keep dirt out. A rear main seal wraps the back of the crankshaft; cam seals close off the ends of the camshafts; TGV and shaft seals handle intake and accessory shafts. When one hardens or splits, you get drips, low oil, and a mess on the bellhousing - which is why people replace them during a clutch job, a timing job, or any teardown where the shaft is already exposed. Fitting a fresh seal while you're in there is cheap insurance against pulling it all apart again.

What ThreePiece stocks

This category holds 47 seals and seal sets in stock right now, priced from $20 to $152 - the current range for what's on the shelf, not a fixed price. There are 17 brands in the mix. The largest counts come from TwinPower and Cometic Gasket, with Victor Reinz, ARB, Radium Engineering and Torque Solution close behind, plus FAST, S&S Cycle, All Balls Racing, Injector Dynamics, Gates, Vibrant and others. Coverage skews toward Harley-Davidson Big Twins and Sportsters, Subaru WRX and STI, Dodge Ram, Ford, Honda, Mitsubishi Evo, and a set of dirt bikes across model years from 1970 to 2023.

Concrete examples: the MAHLE Original rear main seal set at the top of the price range, the MAHLE Original Cummins rear main seal, the FAST LSXR intake manifold seal kit, the COBB Subaru EJ TGV shaft seal kit, the S&S Cycle left main bearing seal five-pack, and the Torque Solution WRX/STI valve cover cam seals.

How to choose

Start from the job. A single shaft seal fixes one leak point; a seal set or kit gives you every gasket and O-ring for a specific service so you're not chasing a second leak next weekend. Kits like the FAST LSXR and COBB TGV pieces are matched to an assembly, while a single rear main seal is right when only the crank seal is weeping. Buy to the exact application - seal diameters and shaft sizes are not interchangeable - and if you're already inside the engine, replace neighboring seals in the same area while access is easy.

What to order with it

Seals rarely go in alone. Pair them with gasket kits and head gaskets when you're opening the engine, and check bearings if a main or cam seal is worn. Fresh oil filters finish the job, and browse the wider Engine Components section for fittings and other parts.

Fitment and ordering

Twenty-two of these listings carry vehicle fitment data. Not sure which seal matches your engine? Call fitment help at 813-535-5801 or reach us through contact us. Every order ships free, and Affirm and Katapult financing is available at checkout.