partszen Gear Head Gearbox for Husqvarna 324LX 326LX 525L 525LST — Direct Fit Replace 537333802, Durable Gear-Driven Repair

partszen Gear Head Gearbox is an aftermarket replacement gearbox assembly designed to fit Husqvarna string trimmers and compatible models, restoring gear-driven performance without buying a new unit.

If your trimmer’s cutting head has developed play, grinding noise, or erratic rotation, replacing the gearbox is often the fastest way to bring back smooth, reliable operation. This partszen gearbox is built to match Husqvarna part number 537333802 and supersedes earlier numbers 537199202 and 537199201. It also fits a wide range of Husqvarna-produced outdoor power equipment and many equivalent models from brands like AYP, Craftsman, Jonsered, McCulloch, Partner, Poulan, Poulan Pro, RedMax, and Roper.

Will this gearbox fit my Husqvarna trimmer model?

Compatibility depends on the original part number and the model’s specifications. This unit is designed to replace Husqvarna 537333802 and lists direct fitment for models such as 324LX, 324LDX, 326LS, 326LX, 326L, 525L, and 525LST. If your equipment originally used one of the superseded part numbers, this gearbox will likely be a suitable replacement.

• Direct replacement for part number 537333802.
• Supersedes 537199202 and 537199201.
• Confirmed fit for listed Husqvarna models (324LX, 326LX, 525L, etc.).
• May work with equivalent models from AYP, Craftsman, Jonsered and others.

How easy is installation and what will I need?

Installation is straightforward for anyone comfortable disassembling a trimmer head—basic hand tools and a clean workspace are the primary requirements. The gearbox generally bolts onto the lower shaft and connects to the trimmer head; follow manufacturer guidance or a model-specific service manual for torque specs and alignment tips. If you're unsure, a small engine technician or a friendly neighborhood repair shop can complete the swap quickly.

• Basic hand tools (screwdrivers, sockets, pliers).
• Service manual or model-specific instructions recommended.
• Check shaft alignment and fastener torque during reassembly.
• Professional installation option for unfamiliar users.

What performance and durability can I expect from this aftermarket option?

The partszen gearbox is manufactured to meet fit and function for the listed part numbers, offering a cost-effective way to restore normal gear-driven operation. It’s built to withstand routine trimming loads and intermittent heavy use similar to the OEM unit, though longevity will depend on maintenance and how the trimmer is used. Regular lubrication and avoiding over-torquing will help maximize service life.

• Designed to match OEM fit and rotation characteristics.
• Suitable for regular residential and light commercial trimming tasks.
• Durability optimized through correct installation and maintenance.
• Includes the parts pictured in the product listing.

What should I check before ordering to avoid returns?

Confirm your trimmer’s original part number or verify the model’s parts diagram before purchase. Compare the old gearbox’s mounting points, shaft style, and dimensions against the product photos and your machine’s specs. If you have doubts, contact the seller with your model and serial number to ensure compatibility.

• Verify original part number (look for 537333802 or superseded numbers).
• Compare mounting holes and shaft configuration to your unit.
• Confirm model fitment: 324LX, 324LDX, 326LS, 326LX, 326L, 525L, 525LST.
• Ask the seller for clarification if uncertain about fit.

Who is this for: This partszen gearbox is aimed at homeowners, landscapers, and repair shops seeking an affordable, practical replacement for a worn or damaged lower gearbox on compatible Husqvarna trimmers and equivalent models from other brands. It’s a sensible choice for anyone who wants to restore their trimmer’s functionality without paying OEM prices, provided they confirm compatibility and follow proper installation and maintenance practices.