Polaris Crankshaft Bearing Mapping Explained (Guide Included)
If you’ve ever torn down a Polaris engine and thought, “I’ll just order standard bearings—what could possibly go wrong?” that shortcut usually leads to trouble.
Unlike many older engines, Polaris does not use a one-size-fits-all bearing system. Instead, Polaris relies on crankshaft bearing mapping, where crank journals, connecting rods, and crankcases are matched using factory codes and color charts.
Skipping this process—even by a single step—often results in incorrect bearing clearances, leading to low oil pressure, accelerated wear, and ultimately a shortened engine lifespan.
What Is Polaris Crankshaft Bearing Mapping?
At its core, bearing mapping allows Polaris to control oil clearance without machining. From the factory, technicians measure crankshafts, rods, and crankcases, then mark each component with specific codes. Those codes determine which bearing thickness belongs in each journal.
Rather than relying on “one size fits all” bearings, Polaris instead uses:
- Crankshaft codes
- Rod numbers
- Crankcase numbers
- Color-coded bearing sizes
When all values match correctly in the chart, the engine maintains proper clearance for optimal performance. However, when builders skip the mapping, they end up guessing — and engines do not forgive guesses.
Main Bearings vs Rod Bearings (Know the Difference)
Main Bearings
Main bearings support the crankshaft inside the crankcases. In the PDF, Polaris breaks the charts out by model and year so builders can select the correct bearing for each journal location.
- Polaris 2011–2012 RZR 900
- Polaris RZR & Polaris Ranger 900–1000 & General 1000 Non-Turbo
- Polaris Turbo Models
For most models, the charting between rod and main bearings follows the same logic. However, the 2011–2012 RZR 900 and Turbo models use their own rod bearing charts, which must be referenced separately.
Rod Bearings
Proper rod bearing installation on a Polaris crank is vital for preventing catastrophic engine failure by ensuring correct clearance, allowing for a protective oil film between surfaces, minimizing friction, and preventing binding. Incorrect installation leads to overheating, rapid wear, low oil pressure, and eventually a spun bearing or your complete engine seizing up.
The Center Journal Bearing (Important Clarification)
The center journal causes confusion, so it’s worth clearing up correctly.
On RZR 1000, General 1000, and Polaris Turbo engines, the center journal uses a solid bearing only. These engines feature a locating notch in the case journal that aligns with the tab on the solid bearing. Because of that design, an oil-gallery bearing physically cannot be installed in this position.
The purpose of the solid center and what it provides:
- Increased surface area
- Greater load capacity
- Improved strength at high RPM
- Longer service life in high-horsepower applications
As a result, the solid center bearing improves durability and longevity in performance-focused UTV engines.
Important: This configuration does not apply to every Polaris model. Always confirm your engine family before selecting center bearings.
How to Use the Bearing Mapping Chart Correctly
Although the charts appear straightforward, the process still demands close attention.
- First, locate the crankshaft code stamped on the crank
- Next, verify the rod numbers and orientation
- Then, check the crankcase numbers. Some cases have 6 digits; in this instance, you do not need to worry about those last two digits as they do not pertain to the mapping that needs to be done for your main bearings.
- After that, cross-reference all values in the chart
- From there, select the correct bearing color for each journal
- Finally, confirm the correct center journal bearing for your model
When even one number is ignored, the chart no longer applies.
Crankcase Numbers (Important Note)
Most Polaris crankcases display a four-digit case number. However, some cases use a six-digit number.
When a six-digit case number is present, simply drop the last two digits and use the remaining four-digit number when referencing the bearing chart.
Why Plasti-Gauging Still Matters
Even with accurate bearing mapping, no chart is completely foolproof. For that reason, we strongly recommend Plasti-gauging during final assembly.
Plasti-gauge is a proven method for verifying bearing clearance. The process uses a soft, precision-sized plastic thread that compresses between the bearing and journal. Once flattened, the width of the material is compared to a calibrated scale to confirm actual clearance.
By combining bearing mapping with Plasti-gauging, builders verify clearances instead of assuming them, which dramatically reduces the risk of premature failure.
Common Bearing Mapping Mistakes
In the shop, the same issues show up repeatedly.
- Ordering “standard” bearings without checking factory codes
- Mixing rod bearing charts with main bearing charts
- Assuming all center journals use the same bearing type
- Ignoring six-digit crankcase numbers
- Skipping Plasti-gauging during final assembly
Most bottom-end failures are not mysterious. Instead, they trace back to incorrect bearing selection or skipped verification.
Download the Polaris Crankshaft Bearing Mapping PDF
If you’re rebuilding a Polaris 900 or 1000 — turbo or non-turbo — this PDF belongs on your workbench.
- Main bearing charts
- Rod bearing charts
- Turbo-specific bearing mapping
- Journal position diagrams
- Critical bearing notes
Download the Polaris Crankshaft Bearing Mapping PDF
Final Shop Takeaway
Polaris bearing mapping works when builders follow the chart, understand the engine family, and verify clearances. When those steps happen together, engines run quieter, live longer, and survive high-RPM abuse.
Use the chart, confirm with Plasti-gauge, and build it once.
