7 Best Shim Sets For Bearing Alignment For Farm Equipment

Nothing stops a harvest faster than a misaligned drive shaft or a vibrating bearing housing on a piece of critical machinery. Taking the time to properly shim these components isn’t just about reducing noise; it is about extending the life of your equipment and preventing catastrophic field failures. Here are the best shim sets to keep your farm gear running smooth and true throughout the season.

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Precision Brand Slotted Shim Kit: Top Overall Pick

For the hobby farmer who needs a “do-it-all” kit that handles most common tractor and implement repairs, this set is the industry standard. It features a wide range of thicknesses and sizes, ensuring that you can tackle everything from a loose PTO drive line to a misaligned pump mount. The slots are precision-cut, allowing for quick installation around bolts without requiring total disassembly of the housing.

The primary advantage here is versatility; the kit is comprehensive enough that it rarely leaves the user hunting for a specific size mid-repair. Because it includes a durable, organized case, these shims stay flat and clean in a busy, dusty shop environment.

This kit is the ideal choice for those who want a one-and-done purchase. It eliminates the need to buy individual sizes and pays for itself after just a few successful alignments.

Steelman Color-Coded Plastic Shim Assortment

Plastic shims offer a unique advantage when dealing with components that might be subject to mild corrosion or where vibration damping is a priority. This set is color-coded by thickness, which makes identifying the right shim in the heat of a repair significantly faster. Because they are made of high-quality plastic, they will not rust or seize to the machine surface, making future adjustments much easier.

These are particularly useful for lighter equipment, such as garden tractor attachments or small tiller gearboxes. They conform slightly to surface imperfections, which helps in sealing gaps that rigid metal shims might miss.

These are not for high-heat applications or high-torque, heavy-load structural joints. Choose this set if your primary focus is on preventing galvanic corrosion or handling minor shimming tasks on light-duty gear.

SKF LAGS Series Slotted Shims: Pro-Grade Choice

When dealing with high-precision equipment like heavy-duty balers or forage harvesters, the quality of the shim matters as much as the thickness. SKF is a global leader in bearing technology, and their LAGS series reflects that engineering focus. These shims are burr-free and perfectly flat, ensuring that the load is distributed evenly across the entire shim surface.

Using inferior, uneven shims can introduce new stresses into a bearing housing, actually exacerbating the problem they are meant to solve. The SKF set minimizes this risk, providing a stable, reliable foundation for high-speed shafts and high-load implements.

Invest in this series if you are working on expensive, core machinery that cannot afford a failure during peak harvest. They are more expensive than generic alternatives, but the peace of mind they provide for critical-path equipment is worth the premium.

Martin Sprocket & Gear Slotted Steel Shim Set

Martin is a staple in agricultural supply houses, and their shim sets reflect a practical, utilitarian design philosophy. These are rugged, no-nonsense steel shims designed for the realities of a farm shop. They are perfectly suited for heavy industrial-style machinery where tolerances are slightly more forgiving but load-bearing requirements are high.

The steel construction handles significant compression without deforming, making them perfect for mounting heavy motor bases or transmission housings. They are durable enough to be reused multiple times if removed carefully during equipment teardowns.

Choose these if your farm equipment relies on heavy, cast-iron components and requires industrial-strength support. They are a workhorse solution for the farmer who prioritizes structural integrity over high-precision, fine-tuned clearance adjustments.

Accupro Stainless Steel Shim Stock Assortment

Stainless steel is the gold standard for rust resistance, and the Accupro assortment brings that reliability to the shop bench. In the damp environment of a farm shed or when working on equipment exposed to fertilizer and chemicals, standard steel shims can rust into place over time. Stainless shims prevent this seizing, ensuring that you can adjust or replace them years down the road.

This set is excellent for the farmer who builds custom brackets or needs to fabricate thin spacers for specific, non-standard repair scenarios. The material is tough and resists shearing under pressure.

If you are located in a high-humidity area or work on implements that deal with corrosive materials, stainless steel is non-negotiable. This assortment is the best way to keep a supply of corrosion-proof material on hand for custom needs.

McMaster-Carr Brass Shim Stock Roll Assortment

Brass shim stock is a classic for a reason: it is incredibly easy to cut to size with simple shop shears and resists corrosion remarkably well. While it does not offer the tensile strength of stainless steel, it is perfect for fine-tuning clearances in smaller, lower-load mechanisms. Many farmers use these to dial in the lash on small gear sets or to square up light mounting brackets.

The convenience of a roll allows for creating custom-length shims that a standard slotted pre-cut shim simply cannot provide. This is a must-have for the tinkerer who frequently works on vintage equipment or older, hand-me-down implements.

Opt for these when the specific dimension required isn’t a standard pre-cut size. They are invaluable for “fit-it-as-you-go” repairs where precision and adaptability are more important than sheer structural strength.

All-Spec 300 Stainless Steel Shim Assortment

This set is built for precision and long-term durability, utilizing 300-series stainless steel for superior performance. The 300-series offers great workability while maintaining excellent resistance to chemicals and outdoor elements. It is an ideal middle ground for farmers who want the strength of steel but the longevity of a corrosion-resistant material.

The set is organized to make finding the right thickness immediate, reducing the frustration of trying to guess which shim fits the gap. Because they are consistently machined, you can stack them with confidence knowing the combined thickness is accurate.

This is a great, professional-grade addition to any well-equipped farm shop. If you want a kit that covers the widest range of durability and precision needs without jumping into specialized industrial brands, this is the right pick.

Choosing Stainless, Brass, or Plastic Shims

• Stainless Steel: Best for high-load, structural applications exposed to moisture or corrosive fertilizers. It will not crush or rust over time.
• Brass: Best for delicate adjustments or custom-cutting spacers. It is easy to work with and highly corrosion-resistant, but it is too soft for heavy, high-impact structural loads.
• Plastic: Excellent for dampening vibration and preventing galvanic corrosion between dissimilar metals. Use them on light-duty gear, but avoid them in high-heat zones where they might melt or deform.

Always evaluate the load requirement before selecting a material. A shim that is too soft will eventually compress, causing the equipment to fall out of alignment again shortly after the repair.

How to Properly Measure Your Alignment Shims

Never guess a gap width by eye; always use a set of feeler gauges to measure the space between the housing and the mount. Once you have the measurement, choose a combination of shims that is slightly thinner than the gap to allow for minor clamping force.

When stacking shims, always place the thickest shims at the bottom of the stack to ensure stability. Avoid using too many thin shims in a single stack, as this can create a “mushy” connection that shifts under load. If you find yourself using more than four or five shims in one spot, consider finding a single shim closer to the required thickness.

Storing Shims to Prevent Damage and Save Time

Shims are precision parts; if they get bent or creased while sitting in a junk drawer, they lose their ability to maintain accurate alignment. Always store them in their original cases or a dedicated organizer box that keeps them flat.

Applying a thin coat of light machine oil to steel shims before long-term storage can prevent flash rust if your shop is not climate-controlled. Keeping them organized by thickness not only saves time during a repair but prevents the temptation to just “grab whatever fits,” which is the fastest way to cause future equipment damage.

Proper alignment is the difference between equipment that works for you and equipment that constantly breaks down in the field. By stocking the right shim sets and applying them with care, you are making a long-term investment in the reliability of your farm. Consistent maintenance keeps the wheels turning when the work really matters.