Gearbox & Transmission Rebuild: What Components You Need

If your Honda Acty is grinding into gear, slipping out of drive, or leaking from the bellhousing, it might be time to rebuild the transmission. Whether you’re restoring an aging workhorse or prepping a kei truck for off-road abuse, understanding what’s inside the gearbox—and what wears out—is the first step. This guide breaks down the key components, common failure points, and upgrade opportunities when rebuilding a manual or automatic Acty transmission.

1. Acty Transmission Overview

Depending on your model and generation, the Honda Acty came with:

• Manual (4-speed or 5-speed) — most common in HA3/HA4/HH3/HH4

• 3-speed automatic — found mostly in later vans (often with AWD)

All variants are compact and relatively easy to work on—but parts availability varies.

2. Common Signs You Need a Rebuild

• Grinding between gears (especially 2nd or reverse)

• Popping out of gear while driving

• Difficulty shifting or sticking in gear

• Leaking fluid at bellhousing or rear seal

• Clutch working fine, but no forward motion