Sumo Gear 23-Spline RF1A Transfer Case Input Gear | 2.28:1 (1984-95 4Runner / 1979-95 Pickup)

Sumo Gear 23-Spline RF1A Transfer Case Input Gear

For 1984–1995 Toyota 4Runner and 1979–1995 Toyota Pickup 4WD RF1A builds configured for a 23-spline input

Overview

The Sumo Gear 23-Spline RF1A Transfer Case Input Gear is a stock-ratio input gear for Toyota RF1A gear-driven transfer cases. It provides a 23-spline input while retaining the factory-style 2.28:1 low-range ratio, making it suitable for factory 23-spline applications and properly configured dual-case, crawl-box, and drivetrain-conversion builds.

Choose the standalone input gear when only the gear is needed, or select the service-bundle configuration to add the matching input bearing and RF1A overhaul gasket kit while the transfer case is apart.

Key Features

• 23-spline input for matching RF1A configurations
• Retains the factory-style 2.28:1 low-range ratio
• Designed for Toyota RF1A gear-driven transfer cases
• SCM420 alloy-steel construction
• Available as a standalone gear or with complementary service components

23-Spline Input & 2.28:1 Ratio

The factory Toyota gear-driven 23-spline application is associated with the 1986–1987 22R-TE Turbo Pickup equipped with the R151F 5-speed manual transmission. Most naturally aspirated 20R, 22R, and 22RE RF1A applications use a 21-spline input and require the appropriate 23-spline conversion components before this gear can be used.

This gear retains the 2.28:1 stock-style low range; it is not a 4.7:1 crawl gear set.

Vehicle Fitment

Factory 23-Spline Application

• 1986–1987 Toyota Pickup – 22R-TE Turbo – R151F 5-Speed Manual – 4WD – RF1A Gear-Driven Transfer Case

Converted RF1A Applications

• 1984–1995 Toyota 4Runner – 4WD – RF1A gear-driven transfer-case build converted to a matching 23-spline configuration
• 1979–1995 Toyota Pickup – 4WD – RF1A gear-driven transfer-case build converted to a matching 23-spline configuration

Fitment Notes

• RF1A gear-driven transfer cases only.
• Requires a 23-spline input configuration.
• Factory V6 chain-driven transfer cases require an appropriate RF1A conversion.
• Modified and dual-case vehicles must be matched to the actual transfer-case type, spline count, transmission, adapter, and coupler configuration.
• The service-bundle configuration does not include the 23-spline transfer-adapter oil seal. Inspect the existing seal and replace it separately if worn, damaged, hardened, leaking, or removed during service.
• Do not substitute the smaller 32 mm transfer-adapter seal used with other configurations.

Product Specifications

Brand: Sumo Gear
Product Type: Transfer Case Input Gear / Service Bundle
Transfer Case: Toyota RF1A Gear-Driven
Input Spline: 23 Spline
Low-Range Ratio: 2.28:1
Material: SCM420 Alloy Steel
Drivetrain: 4WD

Related RF1A Parts & Identification

For transfer-case identification, spline and shifter information, see the RF1A Transfer Case Identification Guide. Builds that also need deeper low-range gearing can use the Sumo Gear 4.7:1 RF1A Transfer Case Gear Set.

Available Configurations

• 23-Spline Input Gear — one 23-spline 2.28:1 RF1A transfer case input gear.
• Input Gear + Bearing & Gasket Service Bundle — includes the 23-spline 2.28:1 RF1A input gear, matching transfer input-gear radial bearing, and RF1A transfer-case overhaul gasket kit. The 23-spline transfer-adapter oil seal is not included.