CMI high-strength stainless steel crank pulley bolt and washer kit for VW Type 1 air-cooled engines. A direct upgrade over the soft, mild-steel factory hardware that strips, stretches, and corrodes — common failure points on stock and performance air-cooled builds alike.

Why the factory crank pulley bolt fails

The stock VW crank pulley bolt is a known weak point on the Type 1 engine. It threads into the front of the crankshaft and carries the load of the entire pulley, fan belt, and alternator system. Over time — and especially on engines that have been apart multiple times for service — the factory bolt threads stretch, the head deforms, and the washer corrodes against the pulley face. Owners often discover this only after the bolt backs out at speed, which sends the pulley, fan belt, and sometimes the alternator across the engine bay.

The CMI kit replaces both the bolt and washer with stainless steel parts machined to higher tolerances than the factory hardware.

Specifications

• Material: Stainless steel (bolt and washer)
• Application: Crankshaft front pulley fastener
• Sold as: Bolt + washer kit
• Manufacturer: CMI
• Part number: #A07

Fitment

• All VW Type 1 air-cooled engines (Beetle, Karmann Ghia, Type 3, Thing, Bus through 1971)
• Dune buggies, sand rails, and kit cars running Type 1 engines

Will NOT fit: Type 4 engines (1972+ Bus, 411, 412, Porsche 914), which use a different crank pulley fastener system.

FAQ

Do I need to use thread locker?
Yes. Even with upgraded stainless hardware, a thread locker (medium-strength, blue) on the crank pulley bolt is standard practice. The pulley bolt sees vibration and harmonic load constantly.

What torque spec should I use?
Follow the standard VW crank pulley bolt torque spec for your engine (typically around 33–40 ft-lbs for the factory bolt). The CMI bolt is stronger than the factory unit, but over-torquing into the crank threads can still strip the crankshaft, which is a much more expensive failure.

Will stainless galvanically react with my aluminum pulley?
The washer is stainless, which means it won't corrode against the pulley face the way the factory plated steel washer does. A light film of anti-seize on the bolt threads (not the bolt head) is recommended for any future removal.

Can I reuse my old pulley?
Yes — this kit replaces the fastener only, not the pulley itself. If your pulley is in good shape, this is a quick, low-cost upgrade.

Is this the same as the "crank pulley bolt kit" sold for performance pulleys?
Functionally yes — same thread, same general application. Some aftermarket performance pulleys come with their own hardware; if yours did, you don't need this.