Splitting your crankcase halves is serious business. Whether you are recovering from a seized rod bearing or completing a scheduled top- and bottom-end overhaul, setting up your rotating assembly with the correct clearances is what prevents you from having to tear the engine down twice.

In this guide, we walk you through the exact process our master technicians use at REV6 to install piston rods, select color-coded crank bearings, and seat the crankshaft on Polaris Ranger 1000, Ranger 900, and RZR 900 engines.

Watch the Full Video Tutorial

Video Chapters & Jump Links

• 00:40 – Required Tools & Chemicals
• 01:37 – Piston & Rod Preparation
• 06:29 – Installing Rods to Pistons
• 11:15 – Main & Rod Bearing Selection (Color Coding)
• 17:07 – Bearing Installation & Tang Alignment
• 23:11 – Seating the Crankshaft
• 27:07 – Torque Specs & Sequences
• 30:48 – Applying Case Sealant & Final Assembly

Tools & Supplies You’ll Need

• Torque Wrenches: Digital torque wrench (for angle/degree specifications) and a 1/4″ drive torque wrench for case bolts.
• Sockets: 8mm, 10mm (rod cap bolts), and 13mm (case bolts).
• Lubricants: High-grade engine assembly lube, assembly grease, and fogging oil (for cylinder wall prep).
• Sealing & Prep: Quality gasket maker/case sealant, contact cleaner, and a rubber mallet.

Step 1: Piston & Rod Orientation

1. Identify Directionality: Inspect the piston crown for an “EX” stamp or directional arrow. This side must face the exhaust manifold to guarantee proper valve relief clearance.
2. Never Swap Rod Caps: Connecting rod caps are precision-mated to their specific rods. Swapping caps between rods causes uneven clearance and rapid bearing failure.
3. Seat Bearing Tangs: Verify that the bearing locating tangs nest cleanly into the machined slots in both the rod and cap without binding.

REV6 Builder Tip: Skip standard work gloves when sliding pistons into the cylinder bore. Clean, bare hands give you the tactile feel needed to ensure piston rings don’t hang up or bind during insertion.

Step 2: Cracking the Bearing Selection Code

Polaris engines do not use a single “standard” bearing size. Instead, bearings are color-coded (typically Green, Yellow, or Blue) to compensate for microscopic journal tolerances:

• Work in Order: Read your stampings starting from the Mag (Magneto) side over to the PTO (Power Take-Off) side.
• Cross-Reference: Match the letters stamped on your crankshaft journals against the stamped numbers on your case halves and rod caps.
• Verify with Plastigage: When reusing seasoned cases or building high-load machines, lay Plastigage across journals before final torque to confirm your oil clearances match factory spec.

Step 3: Crankshaft Installation & Torquing

• Lube Bearings Properly: Coat the bearing shells’ running surfaces with assembly lube. Keep the back of the bearings and case saddles completely clean and dry.
• Seat the Crankshaft: Gently lower the crankshaft into position, aligning your timing drive sprocket smoothly into the case half.
• Apply Perimeter Sealant: Lay down an even, continuous bead of case sealant, keeping it clear of internal oil feed passages.
• Follow Torque Specs: Tighten bolts in the factory crisscross sequence in gradual stages, finishing with final torque angle degrees.
• Check Rotation: Turn the crankshaft over by hand. It should spin freely and smoothly with no tight binding spots.
• Polaris Crankshaft Bearing Mapping Guide

Rebuild It Right with REV6 Components

Reusing fatigued rods, worn bearings, or grooved journals risks destroying your build from the inside out. Use the exact components engineered for your machine:

• Polaris Ranger 900 Rod & Piston Replacement Kit – Matched pistons, wrist pins, rings, and connecting rods designed to restore compression.
• Polaris RZR 900 Complete Bearing & Seal Kit – Establish precise crank oil clearances and protect your rotating assembly.
• Polaris RZR / Ranger 900 Crankshaft Assembly – Precision-balanced replacement crank built to drop right into your ProStar cases.
• Explore All Polaris Engine Rebuild Kits – Top-end, bottom-end, and master kits backed by our 1-year warranty.

Need Help with Your Build?

Skip the Teardown: Professional REV6 Engine Rebuild Services

Precision top- and bottom-end assembly demands the right specialty tools, meticulous cleanliness, and zero margin for error on bearing clearances. If you’re missing torque-angle gauges or would rather not risk a high-dollar mistake on your rotating assembly, REV6 is here to support you at every stage.

Every day, independent repair shops, certified powersports dealers, and serious DIY riders nationwide ship their Polaris RZR and Ranger engine cores directly to our facility. Instead of losing weekends measuring journals or waiting on parts, our core rebuild service provides the fastest, most dependable path back to the trail:

• Decades of Specialized Experience: Our dedicated master technicians rebuild hundreds of Polaris ProStar platforms every year. We know every casting nuance, oil-gallery passage, and wear pattern across 900cc and 1000cc engines.
• Built Better Than New: Factory engines leave the assembly line built to standard production tolerances. Every REV6 remanufactured engine receives upgraded internal components—including premium high-silica pistons, heavy-duty valvetrain components, and precision-matched bearings designed to outlast OEM reliability.
• Turnkey Convenience: Simply pull your engine, drain the fluids, box it up, and send in your core. We handle precision machine work, cleaning, dynamic balancing, and final bench assembly. You receive a ready-to-drop-in engine backed by our 1-year no-fault engine core rebuild warranty.

Frequently Asked Questions

Rebuild with Confidence: Kits or Full Reman, REV6 Has You Covered

Whether you’re in the garage assembling the rotating assembly yourself or want the peace of mind of a drop-in remanufactured engine, REV6 is built to keep you riding:

• DIY Builders: Browse our complete catalog of precision-matched Polaris Engine Rebuild Kits—including rods, pistons, bearings, and crankshafts backed by our 1-year warranty.
• Core Exchange Service: Ship your engine core directly to our Utah facility. Our master technicians handle the precision machining, clearance blueprinting, and complete assembly so you can drop it in and go.

Have questions about bearing tolerances, kit fitment, or sending in your core? Call our shop directly at (801) 489-8697 or reach out through our Contact Us page—let’s get you back on the trail, fast!