5173 Hollywood Blvd, 307, Los Angeles, CA 90027, United States Mon–Sat 9:00am – 6:00pm PT · Sun closed
Parts desk +1 (209) 373-5717 Mon–Sat 9:00am – 6:00pm PT

Car Transmissions

02-05 Honda Civic Si K20A3 5-Speed Manual LSD Transmission

Honda

$1,018.89

Part price only. Freight is quoted for your ZIP before you pay — a gasket set and a 425 HP outboard are not the same shipment, so nothing is guessed at checkout.

In stock — ready to dispatch

Buy JDM 02-05 Honda Civic Si K20A3 5-Speed Manual LSD Transmission. Perfect for K-Swap projects, low mileage, fully tested, and ready for performance builds.

Part number checked before dispatch Send the model, year and serial range and we confirm this is the right number for your unit — including whatever it supersedes.
Quoted freight, insured in transit Small parts by parcel, engines and outboards crated on a pallet. You see the figure for your ZIP before you pay.
2% off when you pay in crypto Also Zelle, bank wire, Cash App, Chime and Apple Pay. No card details taken on this site.
Fitment help before you buy Call +1 (209) 373-5717 — Mon–Sat 9:00am – 6:00pm PT · Sun closed

Description

02-05 Honda Civic Si K20A3 5-Speed Manual LSD Transmission (K-Swap Gearbox)

Upgrade your Honda project with a genuine JDM 02-05 Honda Civic Si Manual Transmission (K20A3, 5-Speed with LSD). Perfect for K-Swap builds, this gearbox provides smooth shifting, durability, and improved traction thanks to its Limited Slip Differential (LSD).

Key Features

  • Fitment: 2002–2005 Honda Civic Si (EP3)
  • Engine Compatibility: K20A3, K20A, K24A
  • Transmission Type: 5-Speed Manual (MT, Cable Operated)
  • Differential: Factory LSD (Limited Slip Differential)
  • Condition: JDM Imported, low mileage, fully tested

Why Choose This K20A3 LSD Gearbox?

The K20A3 5-Speed LSD Transmission is one of the most popular choices for K-Swap projects into older Honda chassis, including Civic EK, EG, DC2 Integra, and CRX. The factory LSD provides better grip and traction for street and track driving compared to open differentials, making it an ideal upgrade for enthusiasts.

Applications

  • Direct fit for 2002–2005 Honda Civic Si (EP3)
  • Compatible with K-Swap projects (Civic, Integra, Accord, CRX)
  • Works with K20A3, K20A, and K24 engine swaps

Helpful Resources

K20A.org – K-Swap Community ·
Hondata ECU Tuning ·
Shop More JDM Transmissions

What’s Included

  • 02–05 Honda Civic Si K20A3 5-Speed LSD Transmission
  • SPTM cable gearbox assembly
  • LSD (Limited Slip Differential) pre-installed
  • Clutch housing (where applicable)
  • Shift linkage not included (sold separately)

Note: Professional installation is strongly recommended. Please confirm compatibility with your ECU, mounts, and clutch system before purchase.

Talk to the parts desk

Give us the model, year and serial range. We confirm the part and quote the freight together.

No call centre and no quote-chasing — you get a real figure, in writing, from someone who can read a parts diagram and knows what supersedes what.

WhatsApp