Lubrication and threaded fastener preparation

This section explains general information about lubrication of parts and threaded fasteners. For specific instructions, see the information about the part in Chapter 3.

Loctite applications

Trek uses Loctite®, or similar product, in a variety of applications in fabrication and assembly of our bikes. Here’s a partial list, and the recommended Loctite product:

Use Loctite carefully. Follow the instructions on the package, avoiding contact with your skin, or inhaling the vapors. As noted on the package, Loctite contains a known carcinogen.

For Loctite to work correctly, the parts must be clean and dry, with no grease, oil, or dirt. Loctite Kleen ‘N Prime is an excellent cleaner and will reduce fixture time.

With blue 242 Loctite, apply to the threads prior to assembly. It will set up in 20 minutes, with full cure taking 24 hours. With green 290 Loctite, application is recommended after assembly. However, this can be impractical with hidden threads, like on the rear suspension pivot bolts or rear suspension bushings. 290 is set in 3 minutes, and again requires 24 hours for a full cure. Please do not confuse Loctite 290 with Loctite 640 or 680, which are also green, as these can make disassembly much more difficult.

Re-application

After loosening a threaded fastener that had Loctite, the Loctite bond has been broken. For this reason, the Loctite must be re-applied.

Recommended grease applications

Most threaded fasteners will benefit from the application of a light grease-type lubricant. This prevents corrosion and galling, as well as allowing a tighter fit with a given torque. For this reason, it’s a good idea to lubricate almost all threaded fasteners. But some fasteners and parts interfaces really need grease.

When lubricating parts for assembly, only a thin film of lubricant is necessary. Any excess lube must be removed or it will attract dirt.

Places to avoid lubrication

Carbon fiber parts lubrication