OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Cone siezed on PTO Shaft

Hi Team, first time poster. I did my first Reno on a 45 I picked up. I've had trouble with the Thrust Pad melting on start up. Upon further investigation, I have since found that the Cone is siezed on the PTO Shaft which I believe is the cause.

I'm having a terrible time trying to separate the two, does anyone have any ideas or tricks to get the cone off the shaft?

Thanks in Advance

Hi ToryC,

Can you post some images of the area please so we are not guessing.

Hi ToryC,

This is what I saw online might be worth a try.


✅ 1. Penetrating Oil + Time (Not WD-40)

Use a proper penetrant:

Kroil

PB Blaster

CRC Freeze Off

Inox MX-5

Soak the shaft where the cone meets it from both ends if possible.
Let it sit overnight—this alone sometimes breaks the bond.

✅ 2. Apply Axial Heat (But Carefully)

The cone is mild steel; the shaft is hardened.
You want to expand the cone, not the shaft.

Method:

Use a MAP gas torch (preferred) or propane.

Heat only the outer cone hub, keep heat away from the thrust pad area.

Heat slowly and evenly until it’s too hot to touch but not red-hot.

Quickly apply more penetrating oil (it will wick in as it cools).

🔥 Do NOT heat the shaft directly—you can ruin its hardness.

✅ 3. Use a 2- or 3-Jaw Puller—But With a Spacer

If you grab the edges of the cone without supporting the PTO shaft, you risk:

bending the shaft

collapsing the cone

damaging the bearing or crankcase

Proper setup:

Put a short, thick bolt between the puller center screw and the PTO shaft end so the shaft isn’t mushroomed.

Position jaws under the meatiest part of the cone, not the edge.

Tighten preload, then:

tap the cone hub LIGHTLY with a hammer (to shock it),

tighten a little more,

tap again.

These cones usually release with a loud POP.

✅ 4. The “Heat + Puller + Shock” Combo (Most Effective)

Heat the cone hub as above.

Apply tension with the puller.

While under tension, strike the hub sharply radially (sideways) with a brass hammer.

This breaks corrosion bonds extremely well.

✅ 5. If You Have No Puller: The Wedge Trick

Last resort—only if you accept risk of replacing the cone.

Heat the cone hub.

Insert two opposing cold chisels or pry wedges behind the cone (NOT between cone and thrust pad).

Tap them in evenly, alternating sides.

⚠️ This method can crack cones, so use only if replacements are available.

❗ Avoid These Mistakes

Do not hammer the shaft end directly (it will mushroom and trap the cone forever).

Do not apply red-hot heat (you’ll wreck the temper of the shaft).

Do not pry against the crankcase.

Do not clamp vice grips to the shaft—scratches create future binding.

🧼 After It Comes Off

Clean everything:

Wet-sand the PTO shaft with 800–1200 grit

Polish with metal polish

Apply anti-seize before reassembly (very important!)

Check:

Cone bore for scoring

Thrust pad flatness

PTO shaft straightness

Keyway condition

Cheers
Max.