Pullers: what Claude and GPT would buy

Two AI models chose on their own, with no web access. Nobody tested these products: this is what each one says, and how to check it.

They disagree: Claude chooses Posi Lock and GPT chooses OTC

In Automotive, Claude and GPT choose the same brand in 60 of 112 categories.

Claude Opus 5.5 · October 27, 2026

Posi Lock Puller (line)

Its cage locks the jaws around the part so they cannot slip off under load, which makes it the safest general-purpose puller for gears, pulleys and bearings.

Not for: Anyone pulling parts with no exposed lip, such as a bearing pressed flush against a shoulder (that needs a splitter), or bolt-on hubs like harmonic balancers and steering wheels.

GPT 6.1 Sol · November 10, 2026

OTC 9-Way Slide Hammer Puller Set 4579

Versatile slide-hammer kit handles common axle, hub, bearing, and gear removal jobs with multiple pulling attachments.

Not for: Heavy-duty truck components or applications requiring hydraulic force.

Claude also lists OTC among the brands that matter.

Check before you buy

Puller type matches the part. Use a jaw puller when the part has a lip to grab. Use a bearing splitter when the part sits flush. Use a bolt-type puller when the hub has tapped holes. Using the wrong type is the main cause of slipping jaws and damaged parts.
Reach and spread. The jaw reach must exceed the depth to the back of the part, and the spread must exceed the part's outside diameter with room to spare. Jaws used at the very end of their range grip poorly and tend to fly off.
Jaw retention. Choose cage, chain or self-locking jaws rather than free-swinging hooks for stubborn parts. Jaws that spread under load are the main safety hazard with pullers.
Forcing screw. Use a hardened, fine-thread screw with a replaceable or swivel tip. Use it with an impact wrench only if it is rated for impact use. Fine threads give more force per turn, and a mushroomed tip slides off the shaft center.

Where to find Posi Lock Puller

Zoro
NAPA Auto Parts
Mile-X

Shops seen in search results on November 5, 2026. A shop missing here may sell it too. Nothing was checked by a person.

Brands that matter

OTC: Professional standard across jaw pullers, bearing splitters and service sets.
Posi Lock: Specialist in caged jaw pullers, from small to hydraulic.
Lisle: Strong in bolt-type and vehicle-specific pullers.
Proto: Industrial-grade puller sets and gear pullers.

What to avoid

Cast pot-metal jaws on budget pullers, which bend or crack under real load.
Hammering on the forcing screw while it is under tension.
Pulling on the outer race when the interference fit is on the inner race, which ruins the bearing.

Questions

Should I heat the part before pulling?

Moderate heat on the outer part (not the shaft) helps with seized fits. Never heat a bearing you plan to reuse, or anything near seals or fuel.

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