Incision Wraith Transmission Outputs: Play & Wear Guide

Quick answer

If your Wraith or VS4-10 transmission has noticeable output shaft play, clicking under load, or unusual noise, first check for loose set screws and worn bearings. If play remains, inspect the output shaft for wear and replace it with a quality Incision part. Always verify fitment for your specific transmission before ordering.

Output shaft play in a crawler transmission rarely fixes itself. It starts as a faint click on a steep climb, then becomes a wobble you can feel by hand. Left alone, it accelerates wear on bearings, gears, and the shaft itself, turning a cheap fix into a full rebuild.

This guide walks through the symptoms, likely causes, and corrective actions for Incision Wraith transmission outputs and similar drivetrain parts. You will learn how to diagnose drivetrain slop, when to replace parts, and when to stop and consider a different solution.

Incision Wraith transmission outputs

Symptoms: What Output Play Feels and Sounds Like

A worn or loose output shaft typically shows up as rotational play when you rock the drivetrain back and forth by hand. You might hear a clicking or grinding noise under load, especially when the suspension is bound up. The truck may also hesitate or jerk when you apply throttle from a stop.

Crawler transmission noise can come from many sources, but output-specific issues often sound like a rhythmic tick that changes with wheel speed. If the noise disappears when you disconnect the driveshaft, the problem is likely in the transmission output, not the axle.

• Test with the truck on a stand: rotate one rear wheel and watch for play at the output yoke.
• Listen for clicking that follows wheel speed, not motor RPM.
• Check for vertical or horizontal movement of the output shaft itself.

Likely Causes: From Loose Hardware to Worn Shafts

The most common cause is a loose set screw on the output yoke or gear. This is easy to miss because the screw can feel tight until you apply load. A worn bearing is the next suspect; if the bearing feels gritty or has in-and-out play, it will let the shaft move and cause drivetrain output wear.

Less often, the output shaft itself wears where it rides in the bearing or locker. Incision VDI Universals, for example, are built from heat treated chromoly steel and come assembled, but they still require a tight fit into the locker. If that fit loosens over time, you will get rotational slop that feels like output play.

• Check set screws on yokes and gears before assuming the worst.
• Spin bearings by hand: any roughness or side-to-side play means replacement.
• Inspect the shaft for a visible groove or step where it contacts the bearing.

Corrective Action: Tighten, Shim, or Replace

Start by tightening all set screws with a quality driver. If the play persists, remove the transmission and inspect the output shaft and bearings. Replace any bearing that feels rough. If the shaft shows wear, replace it with a new Incision output shaft or a complete Incision VDI Universal set if your truck uses them.

When reassembling, pay attention to shimming. A small amount of end play is normal, but excessive shimming can preload bearings and cause heat. For Incision VDI Universals, the catalog notes a tight fit into the locker for less rotational slop, and it may require a light press. That tight fit is intentional; do not sand it away.

• Use threadlocker on set screws that see vibration.
• Replace bearings in pairs if one is worn.
• After assembly, recheck play by hand before installing the driveshaft.

When to Stop and Choose Another Option

If you have replaced the output shaft, bearings, and yokes, and the transmission still has excessive play, the issue may be in the gear mesh or the transmission case itself. At that point, further parts swapping may not help. Consider upgrading to a transmission with a more robust output design or consulting a specialist.

Also stop if you are unsure about fitment. The Incision Slipper Eliminator, for example, fits VS4-10 and Original Axial 3 gear transmissions but does not fit newer style molded grey Axial transmissions with a molded motor plate. Ordering the wrong part wastes time and money.

Incision Slipper Eliminator

• If three or more components are worn, a complete rebuild may be more cost-effective.
• Check the manufacturer's fitment notes before buying any output or slipper part.
• When in doubt, ask before you buy.

Diagnosis Checklist: Output Play and Wear

• Rotational play at the output yoke: With the truck on a stand, hold the output yoke and try to rotate it back and forth. A small amount of play is normal, but more than a few degrees indicates worn parts. If play is excessive, inspect set screws, bearings, and shaft.
• Noise under load: Listen for clicking or grinding that changes with wheel speed. Disconnect the driveshaft to isolate the transmission from the axle. If noise disappears with the driveshaft removed, focus on the transmission output.
• Shaft wear: Remove the output shaft and inspect where it rides in the bearing. A visible groove or step means the shaft is worn and should be replaced. Replace worn shafts and bearings together to avoid repeat failures.
• Fitment verification: Before ordering any replacement, confirm your transmission model and check the manufacturer's fitment notes. For example, the Incision Slipper Eliminator does not fit newer molded grey Axial transmissions. If fitment is unclear, stop and ask before you buy.

Parts That Address Output and Drivetrain Wear

• Incision SCX10-II VDI Universals: Built from high quality heat treated chromoly steel, come assembled for easy installation, and provide a tight fit into the locker for less rotational slop. May require light press into locker. Not for use with original Axial SCX10. These are a direct upgrade for SCX10-II based drivetrains and reduce slop at the output, but you must verify your axle and locker compatibility before ordering.
• Incision Slipper Eliminator: Provides a lockout for the spur gear to transmit 100% of the power to the wheels. Slipper lockout plate is machined for the most popular spur gear bolt patterns. Fits VS4-10 and Original Axial 3 gear transmission. Does not fit newer style molded grey Axial transmission with molded motor plate. If you are chasing drivetrain slop and power loss, eliminating the slipper can help, but only if your transmission matches the fitment notes. This is not a universal part.
• Incision Kingpin Shoulder Screws (4): Kingpin Screw replaces the brass bushing and M3 buttonhead with a 1pc shoulder screw. Fits SCX10II Rockjock, SCX10II F9, VS4-10 Rockjock 44. This is a replacement part for the Vanquish VS4-10. While not a transmission output part, these screws reduce slop in the steering and axle assembly, which can contribute to overall drivetrain play and vague handling.

Output play is a warning sign you should not ignore. By checking set screws, bearings, and shaft wear early, you can often fix the issue with a few inexpensive parts. When in doubt, verify fitment and replace worn components together to keep your crawler running smoothly.