How to Lubricate Compound Bow Cam Bearings — The Right Way

"How do I lubricate my cam bearings?" is one of the most searched compound bow maintenance questions — and one of the most likely to lead archers toward doing something that actively damages their bow if they follow generic advice without understanding which system their bow actually uses.

The answer depends entirely on whether your bow uses sealed cam bearings or open bushing-style axles. These two systems look similar from the outside but have completely different maintenance requirements. Lubricating a sealed bearing externally does nothing useful and creates a grit-attracting surface near your string system. Failing to lubricate an open bushing accelerates wear at the highest-friction point on the bow.

This guide covers how to identify which system you have, what to do for each, and the mistakes that damage both.

The Two Cam Systems — Sealed Bearings vs Open Bushings

The shift from open bushings to sealed bearings happened progressively across the industry from roughly the mid-2000s through the 2010s. If your bow was built by a major manufacturer — Hoyt, Mathews, Bowtech, PSE, Bear — within the last ten years, it almost certainly uses sealed cam bearings. If your bow is older or a budget model, it may use open bushings.

How to Identify Which Type You Have

Before touching a lubricant, confirm your cam type using one of these methods:

Method 1 — Check the owner's manual

The most reliable method. Your bow's owner's manual will specify the cam system and any lubrication requirements. Most manuals from major manufacturers will explicitly state whether the cams use bearings or bushings and what — if any — lubrication is required. If you don't have the physical manual, most manufacturers publish them on their website under support or resources.

Method 2 — Visual inspection of the axle ends

Look at the end of the cam where the axle pin exits. On an open bushing system you will typically see a visible gap between the axle pin and the cam body — the bushing gap where oil needs to go. On a sealed bearing system the cam end typically looks cleaner and more finished, often with a visible bearing race or simply a smooth flush surface with no visible gap.

Method 3 — The lateral play test

With the bow unstrung or at brace, gently try to move the cam laterally — side to side — on the axle. Open bushing systems typically allow a very small amount of lateral play. Sealed bearing systems feel solid with virtually no lateral movement. This is not a definitive test on its own but combined with visual inspection it helps confirm.

Method 4 — Contact the manufacturer

If you are genuinely unsure after visual inspection and checking documentation, contact your bow manufacturer directly with the model and year. They will confirm the cam system and provide any specific lubrication guidance. This is the safest approach if there is any doubt.

Sealed Cam Bearings — What to Do (and Not Do)

If your bow has sealed cam bearings, the maintenance guidance is simple: do not apply external lubrication to the bearings.

Sealed bearings are factory-packed with high-quality grease that is designed to last the life of the bearing under normal shooting conditions. The bearing is enclosed — oil applied to the exterior cannot penetrate the seal to reach the bearing internals. It sits on the outside surface, migrates toward the cam grooves and string contact areas, and creates a grit-trapping surface that does nothing useful.

What sealed bearings do need

• Regular inspection — spin each cam by hand before every session. Sealed bearings should rotate smoothly with zero grinding, roughness, or resistance.
• Keeping them clean — wipe the cam body and axle area with a clean dry cloth periodically. You are removing accumulated grit from the exterior surface, not lubricating the bearing.
• Professional attention when needed — if a sealed bearing feels rough, gritty, or develops noise, it needs replacement, not lubrication. This is a bow press job at a professional archery shop.

When sealed bearings need replacement

Sealed cam bearings typically last many years under normal shooting conditions. Signs that a bearing needs replacement include persistent roughness or grinding during cam rotation that doesn't improve after cleaning the exterior, audible noise during the draw cycle localised to a specific cam, visible corrosion on the bearing race, or the cam developing play or wobble it didn't previously have. When these signs appear, take the bow to a professional archery technician.

Open Bushing Systems — Step-by-Step Lubrication

If your bow uses open bushing-style axles, the cam axle is the most critical lubrication point on the entire bow. Here is the correct procedure:

What you need

• GNP Defend Silicone Oil — or any silicone-based lubricant. Never use WD-40, petroleum oils, or general-purpose sprays.
• Lint-free cloths — two or three for cleaning and wiping excess.
• Cotton swabs — optional, useful for cleaning tight spaces around the axle.

Step 1 — Lay the bow on a clean stable surface

Work in good lighting so you can clearly see the axle pin at each cam end. A folded towel on a workbench keeps the bow stable and protects the finish.

Step 2 — Clean the axle area first

Wipe the axle pin and the cam surface around it with a clean dry lint-free cloth. Remove all existing grit, dust, and old lubricant residue. Use a dry cotton swab to clean any debris from the gap between the axle pin and the cam body. This step is not optional — lubricating over existing grit suspends abrasive particles in the oil film and accelerates wear rather than preventing it.

Step 3 — Apply silicone oil to the axle pin

Apply one small drop or a short burst of aerosol to the axle pin at each end of the cam — where the pin enters the cam body. Apply to both sides of both cams: four application points total on a standard two-cam bow. One small application per side is sufficient. The goal is a thin film at the contact point, not a soaking.

Keep oil away from string grooves and cables. Apply precisely to the axle pin only. If oil contacts the bowstring wipe it off immediately — oil on synthetic string fibers breaks down the fiber structure and shortens string life significantly.

Step 4 — Cycle the bow by hand

Draw the bow slowly by hand several times — not to full draw, just enough to rotate the cams through their range of motion. This distributes the silicone oil through the contact surface between the axle pin and the bushing. You should feel cam rotation become slightly smoother as the oil works into the contact zone.

Step 5 — Wipe away excess

After cycling, wipe the cam body and axle area with a clean cloth to remove any oil that has migrated away from the contact zone — particularly near the string grooves and any string or cable contact surfaces. A thin film at the axle contact point is what you want. Any oil visible pooling on the cam surface is excess.

Step 6 — Check the draw cycle

Draw the bow slowly and feel for smooth, consistent cam rotation. Properly lubricated open bushings should feel smooth with no grinding or roughness. If roughness persists after lubrication, the bushing or axle may be worn and requires professional inspection — more oil will not fix worn metal.

How often to lubricate open bushing axles

Every 1,500–2,000 shots under normal shooting conditions. After hunting in rain, mud, or heavy dust, inspect and re-lubricate sooner regardless of shot count. At 100 shots per session that is roughly 15–20 sessions — about one hunting season or a few months of regular range shooting.

Warning Signs Your Cam System Needs Attention

Whether you have sealed bearings or open bushings, these signs indicate something needs attention:

Warning sign	Likely cause	Action
Gritty cam rotation by hand	Dry bushing or worn bearing	Clean and oil (bushing) or inspect (sealed)
Squeaking during draw	Dry axle or cable slide	Clean and lubricate
Cam timing drift	Uneven friction or worn bearing	Professional press inspection
Surface rust on axle pins	Moisture — lubrication displaced	Clean and apply fresh silicone oil
Cam wobble or lateral play	Worn bushing or failed bearing	Professional press service
Inconsistent draw cycle feel	Friction buildup at axle	Clean and lubricate (open bushing)

Common Mistakes to Avoid

Lubricating sealed bearings externally

The most common mistake. Oil applied to the outside of a sealed bearing cannot reach the bearing internals. It sits on the exterior surface, migrates toward string and cable contact zones, and creates a grit-attracting surface near the string grooves. If your bow has sealed bearings, do not apply external lubrication to the cam axle area.

Using WD-40

WD-40 is a petroleum-based solvent, not a lubricant. It evaporates within hours and leaves a sticky residue that attracts grit to the contact surface. Its petroleum distillates also degrade rubber components and composite cam materials. Use silicone oil only. Read our full guide: Can You Use WD-40 on a Compound Bow?

Over-lubricating

Excess oil at cam axle points migrates onto the bowstring and cables. Oil contact with synthetic string fibers breaks down the fiber structure and dramatically shortens string life. One small application per axle end — four points total on a two-cam bow — is the correct amount. More is not better.

Lubricating over grit

Always clean the axle area before applying fresh lubricant. Lubricating over existing grit suspends the abrasive particles in the oil film and grinds them into the contact surface.

Skipping one cam

Always lubricate both cams at the same time. Uneven friction between the left and right cam axles causes cam timing drift — a problem that manifests as inconsistent draw cycle feel and is often misdiagnosed as a tuning or form issue.

Trying to service sealed bearings at home

Sealed cam bearings require a bow press and specialized tools to service or replace. Attempting this without proper equipment damages the bearing, the cam body, and potentially the limb. If your sealed bearings need attention, take the bow to a professional archery technician.

Frequently Asked Questions

Summary

Identify your cam system before touching any lubricant. Sealed bearings — which most modern compound bows use — need no external lubrication whatsoever. Open bushing systems need a small amount of silicone oil at the axle pin every 1,500–2,000 shots. For both systems, clean before you lubricate, never over-apply, and keep oil away from strings and cables.

If your cam system shows roughness, timing drift, or wobble that doesn't respond to cleaning and correct lubrication of an open bushing system, that is a professional press service situation — not a lubrication situation.

View GNP Defend Silicone Oil →    Lubrication Guide →    How to Oil Bow Axles →    Complete Bow Care Guide →