Ratchet wrenches are a standard tool in every mechanic's toolbox. Made in different drive sizes for heavy or lighter-duty uses, ratchets allow you to snap different-size sockets on the ratchet mechanism to remove or tighten bolts quickly. Ratchets have a reverse lever to set the ratchet mechanism's pawls to tighten or loosen bolts while turning the wrench. The ratchet wrench works quicker than standard wrenches because it doesn't need to be reset on every turn. To repair a ratchet wrench, use the proper repair kit for your particular make and model.
Unscrew the ratchet cover plate. The cover plate is on the ratchet head where the sockets snap into place. Using a small Phillips-head screwdriver, remove the two screws holding the plate to the ratchet.
Remove the reverse lever, if necessary. Some ratchet models, such as Snap On, require you to remove the reverse lever when installing a new ratchet mechanism . Some are attached with a small Phillips-head screwdriver, but others may have a securing pin that requires you to tap it out with a hammer and pin punch.
Remove the ratchet gear assembly. As it is spring loaded, be careful not to lose any parts if the spring snaps. Take note of the assembly for reference when installing the new mechanism.
Spray the inside of the ratchet head housing with cleaning solvent and wipe clean, using a rag. There may be small metal shavings in the housing, so wear safety goggles during this step.
Insert the new ratchet gear assembly into the ratchet. Place a few drops of common household oil onto the gear mechanism and reattach the plate onto the ratchet, securing the new gear mechanism in place.
Replace the reverse lever, if necessary. Either re-screw the reverse lever or tap the securing pin into place with a hammer. You have repaired the ratchet wrench.
Verify that the reverse lever is working properly. If the ratchet does not turn in the opposite direction when switched, remove the cover plate to verify that the new mechanism is seated properly, allowing the lever to switch the gear pawls.