Product Function & Specs:

Heavy-duty replacement compression spring designed for hydraulic control valves. Engineered from high-tensile spring steel to maintain precise return tension and spool alignment under constant cyclic pressure. Ensures smooth, predictable valve response inside the machine’s primary hydraulic or transmission control block.

Failure Symptoms:

• Sticky, sluggish, or unresponsive hydraulic control levers.
• Hydraulic spool failing to center properly, causing drift in cylinders or attachments.
• Loss of system pressure or erratic valve behavior due to a fatigued, sagged, or broken spring.

Quick Installation Notes:

• Relieve all hydraulic system pressure completely before disassembling the valve group.
• Clean the valve bore and spool housing thoroughly to prevent any grit or metallic debris from entering the system.
• Compare the free height of the old spring to the new one to verify tension loss; replace any worn matching spools if needed.
• Lubricate the spring and valve spool with clean hydraulic oil prior to reassembly.

FAQ:

Q: Can this part replace OEM 100-3564?

A: Yes, 100% interchangeable. Dimensions, wire diameter, and spring rate match the original Cat specifications exactly.

Q: Is this an OEM or aftermarket replacement?

A: This is a premium aftermarket replacement spring built with high-fatigue resistant spring steel. Same operational life, better cost.

Q: What equipment does this spring fit?

A: It fits a wide array of Cat backhoes (416B/C/D, 420D, 428B/C/D, 430D) and track-type tractors (D5H, D5M, D5N, D6M, D6N). Send us your machine’s serial number or valve group part number to double-check fitment.

Q: Should I replace valve springs individually or as a set?

A: If your control valve block has multiple identical spools that have worked the same hours, we highly recommend replacing them as a set to keep operating pressures and lever feel consistent.

Q: Do you support bulk orders?

A: Yes. We offer competitive wholesale terms for hydraulic rebuild centers, fleet repair shops, and distributors. Contact our sales desk directly for pricing.

Why Sourcing From WinsParts?

We match your part numbers directly against official parts catalogs to ensure a 100% correct fit. Our large physical inventory allows us to ship orders fast, minimizing your machine downtime with dependable parts.

Product Function：

The 8S-3373 Seal Ring is designed to contain hydraulic fluid and engine oil at critical connection interfaces, transmission control valves, and hydraulic oil lines. Manufactured from a high-grade elastomeric compound formulated to withstand continuous heat cycles, mechanical vibration, and system pressure pulses, this seal ring prevents fluid bypass at joint faces. It maintains its cross-sectional tension over extended service intervals to ensure static joint integrity. If this seal ring degrades, flattens, or hardens, it can result in pressure drops, external oil wetness, and potential oil contamination.

Common Failure Symptoms：

• Fluid leakage or oil weeping at the mating joints of hydraulic or engine lines.
• Local pressure drops within the affected fluid circuit.
• Elastomer degradation, such as cracking, flattening, or severe loss of flexibility.
• Accumulation of dirt and grime around the connection interface indicating slow fluid weeping.

Installation Notes：

• Examine the seal groove and mating flanges for any old sealant residue, dirt, or surface pitting before installation.
• Clean the receiving area thoroughly with a non-residue solvent to ensure a dry, clean seal seat.
• Apply a light film of clean system fluid or approved assembly lubricant to the new seal ring to ease installation and avoid pinching.
• Ensure the seal ring is laid completely flat in its groove and is not twisted or over-stretched.
• Tighten the connection bolts in a progressive, alternating sequence to meet the torque specifications in the service manual.

Maintenance Tips：

• Inspect fluid connections and lines during scheduled preventive maintenance checks for any signs of dampness.
• Avoid operating the machinery at temperatures beyond recommended system thresholds, as excessive heat accelerates elastomer aging.
• Always install a brand new seal ring during any maintenance process that requires disconnecting the sealed joint.

FAQ：

Q: Can this part replace OEM 8S-3373?

A: Yes, this part is designed as a direct replacement for OEM part number 8S-3373 (8S3373), matching all original dimensions and technical specifications.

Q: Is this an OEM or aftermarket replacement?

A: This is a high-quality aftermarket replacement seal ring engineered using reliable, wear-resistant elastomeric materials to withstand heavy equipment working environments.

Q: Which machines are compatible?

A: This seal ring fits a range of crawler tractors including the D6R, D6T, and D7R, wheel loaders such as the 966G and 980G, and various engines utilizing the 3306 or 3406 platforms. Please contact us with your equipment serial number to confirm exact fitment.

Q: How should I store the O-ring before installation?

A: Store the seal ring in its original sealed packaging in a cool, dark, and dry environment. Keep it away from direct sunlight, high humidity, and electrical equipment that produces ozone to protect the elastomer compound.

Q: Can I purchase in bulk?

A: Yes, we offer wholesale volume pricing for equipment fleet operators, repair centers, and parts distributors. Contact our sales department with your specific quantity requirements for a detailed quotation.

Why Sourcing From WinsParts?

WinsParts maintains a comprehensive technical database to ensure that our product offerings align directly with original design part numbers. Every batch of our seals undergoes thorough inspection checks to verify dimensional correctness and material quality. Our efficient warehouse management system enables fast packing and shipping, helping B2B buyers around the globe minimize machinery downtime and keep maintenance operations running smoothly.

Product Function：

The 8S-3372 Torque Converter Seal is designed to maintain fluid retention and prevent high-pressure transmission oil from escaping the torque converter housing interface. Engineered from an advanced elastomeric compound that tolerates extreme oil temperatures and shearing forces, this seal ring fits into the converter stator or housing bore to sustain vital internal hydraulic pressure. By providing a continuous barrier, it keeps power train fluids contained while protecting the interior torque converter assembly from atmospheric debris and moisture. If this seal ring degrades or flattens, transmission oil bypass occurs, leading to low charge pressure, slipping clutches, and poor power transfer.

Common Failure Symptoms：

• Oil leaking from the bell housing or torque converter inspection plates.
• Drop in torque converter charge pressure, resulting in sluggish machine acceleration or power loss under load.
• Elevated transmission oil temperatures caused by internal fluid slippage and bypass.
• Elastomer degradation, including hardening, cracking, or loss of cross-sectional elasticity.

Installation Notes：

• Thoroughly inspect the converter housing groove and shaft landing surface for scratches, burrs, or wear ridges before installation.
• Clean the assembly area completely to remove metal filings, varnish, and old oil residue.
• Apply a uniform film of clean transmission oil or approved assembly lubricant to the new seal ring to prevent tearing or rolling during insertion.
• Position the seal evenly within its landing track, ensuring it sits entirely flush and is not twisted.
• Align and mate the torque converter sub-assemblies squarely to avoid pinching or shearing the sealing lip.

Maintenance Tips：

• Perform regular transmission fluid and filter changes to keep abrasive metal fines from scoring the elastomeric seal.
• Monitor transmission oil temperature and pressure gauges closely during operation to identify internal bypass early.
• Always install a new torque converter seal ring whenever the transmission or converter housing is separated for overhaul.

FAQ：

Q: Can this part replace OEM 8S-3372?

A: Yes, this part is engineered as a direct replacement for OEM part number 8S-3372 (8S3372), conforming fully to factory dimensions and operational service requirements.

Q: Is this an OEM or aftermarket replacement?

A: This is a premium aftermarket replacement seal ring built from high-durability, oil-resistant elastomers designed to meet heavy construction machinery performance standards.

Q: Which machines are compatible?

A: It fits numerous heavy machinery models including track-type tractors D6D, D6G, D6H, D6R, and D7G, as well as wheel loaders 966D, 966E, and 966F. Please provide your machine serial number to confirm exact application.

Q: How should I store the O-ring before installation?

A: Store this seal flat in its original protective packaging. Keep it in a cool, dry location away from direct sunlight, high humidity, and ozone-producing electrical equipment to maintain compound properties.

Q: Can I purchase in bulk?

A: Yes, we provide bulk supply terms and contract pricing for commercial rebuild centers, heavy equipment parts dealers, and fleet repair operators. Contact our team with your required quantities for a quote.

Why Sourcing From WinsParts?

WinsParts utilizes deep industry expertise to maintain an extensively verified technical catalog where tracking numbers align perfectly with factory technical files. Our technical team conducts dimensional inspections on every component batch to ensure strict compliance with mechanical tolerances. Backed by a streamlined global logistics infrastructure, we ensure reliable supply lines to help B2B operators minimize unscheduled maintenance delays and maximize machine uptime.

Product Function：

The 8P-8950 Metal Seal Ring is engineered to maintain oil pressure and prevent fluid migration within high-temperature hydraulic paths, planetary transmission groups, and torque converter assemblies. Manufactured from gray iron, this joint-lock type sealing ring withstands continuous rotational wear and high thermal expansion without losing its structural tension. It functions as a dynamic barrier to isolate oil circuits inside heavy-duty gear systems. If the metal ring scores, snaps, or suffers severe face wear, internal pressure drops will occur, leading to clutch slippage or sluggish transmission response.

Common Failure Symptoms：

• Loss of hydraulic circuit or transmission main line operating pressure.
• Delayed or harsh gear engagement caused by fluid bypass at the sealing joint.
• Increased oil operating temperatures due to internal fluid friction and slippage.
• Fine iron scoring particles discovered in the transmission oil filter elements.

Installation Notes：

• Check the shaft landing surface and receiving bore for any grooving, burrs, or ridges before setup.
• Gently expand the metal seal ring over the shaft and ensure the lock joint securely engages without over-stretching the gray iron material.
• Submerge the ring in clean system oil prior to assembly to minimize initial contact friction.
• Verify that the ring rotates freely within its designated carrier groove after seat installation.
• Align mating component sub-assemblies squarely during final integration to avoid shearing the extended edge of the metal seal.

Maintenance Tips：

• Adhere to specified transmission fluid change intervals to keep abrasive particulate from wearing the metal ring faces.
• Monitor pilot pressure readings regularly to identify early signs of seal ring bypassing.
• Always replace the iron seal ring whenever the internal clutch pack or planetary group is disassembled for service.

FAQ：

Q: Can this part replace OEM 8P-8950?

A: Yes, this item is a direct dimensional match for OEM part number 8P-8950 (8P8950), meeting original material and fitment standards for heavy machinery power train lines.

Q: Is this an OEM or aftermarket replacement?

A: This is a high-grade aftermarket replacement ring produced from gray iron to deliver reliable durability equivalent to industrial machinery requirements.

Q: Which machines are compatible?

A: This metal seal fits an extensive range of wheel loaders including the 950B, 950F, and 966C, track tractors like the D5H and D6N, and various skidder configurations. Please check your serial number range with our catalog desk to confirm exact placement.

Q: How should I store the metal seal ring before installation?

A: Store the seal flat in its defensive packaging within a dry environment. Avoid heavy stacking on top of the ring to eliminate the risk of distortion or fracturing the lock joint interface.

Q: Can I purchase in bulk?

A: Yes, we provide wholesale volume terms for regional equipment supply yards, commercial rebuilding shops, and fleet operations. Reach out to our logistics team for specific bulk quantity pricing.

Why Sourcing From WinsParts?

WinsParts maintains a highly responsive physical parts warehouse to ensure inventory availability matches live catalog demands. Every machinery component undergoes comprehensive quality validation before shipment to enforce strict adherence to design prints. We coordinate with established international freight carriers to minimize logistics lag, delivering dependable aftermarket solutions to maintenance teams worldwide.

Product Function：

The primary function of the 8M-5254 Seal O-Ring is to create a reliable fluid seal between static mating surfaces within engine components, fuel systems, and hydraulic junctions. Made from silicone rubber, this sealing element prevents oil or coolant loss under standard operating temperatures and pressures. It maintains its cross-sectional profile to keep external dust and moisture out of critical fluid circuits. If the O-ring degrades or hardens from prolonged service, it can lead to interface weeping, pressure loss, or internal fluid cross-contamination.

Common Failure Symptoms：

• Fluid weeping or localized leaks around engine covers, oil lines, or hydraulic manifolds.
• Gradual loss of system operating pressure near the sealed joint.
• Material hardening, flattening, or surface cracking due to continuous heat exposure.
• Signs of external contamination entering the closed fluid loop past the sealing border.

Installation Notes：

• Inspect the O-ring landing groove for any old adhesive, nicks, or debris before installing the new seal.
• Clean both mating faces thoroughly to ensure a smooth, level sealing surface.
• Lubricate the O-ring with clean system oil or assembly grease to prevent binding during compression.
• Seat the O-ring evenly in the groove without twisting or stretching the elastomer loop.
• Tighten the housing fasteners evenly according to the torque sequence specified in the manufacturer’s manual.

Maintenance Tips：

• Check critical connections for fluid stains during routine preventive maintenance intervals.
• Keep fluid systems clean, as abrasive debris can degrade elastomeric joints prematurely.
• Always install a new O-ring whenever a component cover or fluid line is removed for service.

FAQ：

Q: Can this part replace OEM 8M-5254?

A: Yes, this part is designed as a direct replacement for OEM part number 8M-5254 (8M5254), matching original dimensions and material requirements for heavy equipment service.

Q: Is this an OEM or aftermarket replacement?

A: This is a high-quality aftermarket replacement part engineered to meet standard industry performance guidelines for heavy machinery applications.

Q: Which machines are compatible?

A: It fits various models including articulated trucks 735 and 740, track-type tractors D5H, D6M, and D6N, as well as engines like the 3304 and 3306 series. Please share your equipment serial number to verify your specific fitment.

Q: How should I store the O-ring before installation?

A: Store the O-ring in its original sealed packaging in a cool, dry place away from direct sunlight, ozone sources, or electric motors to prevent premature aging of the material.

Q: Can I purchase in bulk?

A: Yes, we support wholesale volume orders for parts dealers and repair fleets. Contact our team with your required quantities to receive a direct bulk price quotation.

Why Sourcing From WinsParts?

WinsParts specializes in accurate replacement parts tracking, ensuring our catalog numbers correspond directly to factory specifications. Every order undergoes dimensional evaluation before shipment to confirm drop-in compatibility. We maintain a broad physical inventory to process orders efficiently, helping equipment fleets minimize unscheduled downtime with dependable components and clear technical alignment.