CMI Chromoly Nickel-Plated VW Rear Axle Nuts — Heat-Treated Hub Security Upgrade (Pair) | #A13-CMI

CMI chromoly nickel-plated VW rear axle nuts — sold as a pair. Heat-treated chromoly steel replacements for the soft mild-steel factory axle nuts, finished in nickel plating for corrosion resistance. The ultimate hub security upgrade for any VW with rear axles, particularly important on performance, lowered, off-road, or hard-driven cars where the factory nut is at the edge of its specification. Part #A13-CMI.

Why the rear axle nut is one of the most important fasteners on a VW

The rear axle nut holds the rear hub onto the axle. It carries every bit of torque the engine produces, every cornering load, and every braking force on the rear of the car. The factory VW axle nut is made from soft mild steel and torqued to a very high spec — well over 200 ft-lbs — which means installation and removal both stress the threads heavily.

On hard-driven, lowered, swing-axle-to-IRS-converted, or performance cars, it's not unusual for the threads to strip during installation, or for the nut to deform under repeated torque cycles. Strip a rear axle nut and you're looking at a stranded car at best, a wheel separation at speed at worst.

The CMI chromoly version is heat-treated chromoly steel — significantly stronger than the mild-steel factory unit — and nickel-plated against corrosion in the wet, dirty environment around the rear hub. They install with standard tools, torque to factory spec, and last the life of the car.

Specifications

• Material: Heat-treated chromoly steel
• Finish: Nickel plated
• Sold as: Pair (left + right)
• Manufacturer: CMI
• Part number: #A13-CMI

Fitment

• All VW Type 1 rear axles using the standard VW axle nut (Beetle, Karmann Ghia, Type 3, Thing)
• Dune buggies, sand rails, Manx, and other VW-based builds using stock-pattern rear axles
• Both swing axle and IRS rear suspension

Verify thread spec before ordering. VW rear axle nuts have used the same general thread pattern across most production, but custom axle setups (extended axles, race axles, off-road conversions) sometimes use different thread specs. Match this nut to your specific axle threads.

FAQ

What's the torque spec?
The factory VW rear axle nut torque spec is approximately 217 ft-lbs (294 Nm) — verify against your specific service manual. This is a very high torque value and requires a long breaker bar or torque multiplier to achieve correctly. Don't guess on rear axle nut torque — too loose and the hub walks, too tight and you stress the threads.

Do I need a new cotter pin or castle nut configuration?
The VW rear axle nut is a castle-style nut secured with a cotter pin through the axle. Always use a new cotter pin on installation. Never reuse an old one.

Will these work on my swing axle Beetle?
Yes. Swing axle rear axle nuts use the same general thread spec as IRS axles on Type 1 cars.

Are they worth it on a stock daily driver?
For a stock, gently-driven Beetle, the factory mild-steel nut is generally adequate if installed correctly with new threads. The chromoly version is cheap insurance and the right choice if you'll be removing/reinstalling axles multiple times (during a build or service), or if you're running performance modifications that increase rear-end loads.

What happens if I run a worn or damaged factory nut?
Best case, slow loosening over time leading to a wobbly rear wheel that gets caught on inspection. Worst case, sudden thread failure and rear wheel separation at speed. The axle nut is one of those fasteners where "good enough" isn't good enough.

Do they include washers?
This kit is the axle nuts only. The factory VW axle washer should be in good condition or replaced with a known-good unit. If yours is bent or distorted, replace before installing the new nuts.