Crawl Box with Trail-Gear Components

Description

RF1A Gear Driven REMANUFACTURED Crawl Box with Trail-Gear internals.

Assembled Crawl Box feature 2.28 or 4.7 gear ratios. They are available with 21 or 23-spline input and output shafts and with your choice of shifter style.

Match the transmission output shaft spline count and the transfer case input shaft spline count, they will either be 21 or 23-spline, see the chart below for application guide. You can choose the shifter style to also match the transmission and application you are using.

All transfer cases and crawl boxes do not include shift levers.

This crawl box is rebuilt with Genuine seals, KOYO bearings.

All transfer case pieces are glass beaded and all surfaces are machined flat, to ensure a perfect seal.

Features:

Input Spline: 21 or 23
Gear Ratio: 2.28:1 or 4.7:1
Shifter Type: Top, 4 Inch Forward, or 4.5 Inch Forward Shift
Output Spline: 21

Transmission Compatibility Information:

Trucks equipped with V6 engines and Turbocharged 4 Cyl engine will have 23-Spline output shafts and will require 23-spline input on the transfer case. All other engine applications will be 21-spline. Note: The R150F that was equipped in the 1988-1995 3VZ-FE V6 trucks will require an addition adapter to run dual cases.

$500 Core Charge

This Crawl Box has a 1 Year Warranty

10 Day Lead Time

Installation of Dual Cases will require modifications of drivelines and floorboards.

Identifying the RF1A

You are able to identify if you have an RF1A transfer also known as the Toyota Gear Driven case by the number of bolts on the back case cover. If you have 7 bolts on the cover you have an RF1A, Gear Driven case. If you only have 5 bolts then you have a chain driven case.

Difference between Top and Forward Shift Transfer cases

The Differences between Top Shift and Forward shift is fairly self explanatory. A Top Shift RF1A will have the shifter directly on top of the reduction box and alternatively a forward shift RF1A will have shift rails extending out the front with a block off plate on top of the reduction box.

Top Shift Transfer Cases
1979- 7 of 1983 Pick-Up/Hilux
1985-1988 Pick-Up/Hilux
1985-1989 4Runner

Forward Shift 4″ Transfer Cases
1989-1995 Pick-Up/Hilux
1990-1993 4Runner

Forward Shift 4.5″ Transfer Cases
8 of 1983-8 of 1988 Pick-Up/Hilux and 4Runner
1986-1987 Pick-Up/Hilux and 4Runner

Spline Information

For stock applications the only transfer cases that used 23 spline are the 1986 and 1987 Turbo trucks and 4Runners. All other stock 1979-1995 trucks and 4Runners used the 21 spline. If you are build a dual case set up or custom application the 23 spline output shaft is stronger than the 21 spline. However it is important to know your application to be sure it will work in your attend application.

Factory Flange Specifications

1979-1983 (8mm Bolts)

• Front: 60mm x 69mm, 8mm bolts, double cardan
• Rear: 56mm x 64mm, 8mm bolts

1984-1995 (10mm Bolts)

• Front: 60mm x 69mm, 10mm bolts, double cardan
• Rear: 60mm x 60mm, 10mm bolts

Aftermarket Triple-Drilled Flange SKU: T121021

• Universal output flange covering all common 1984-1995 patterns
• Fits both 4-cylinder and V6 applications, including CV and non-CV patterns
• Bolt Patterns:
  • 70mm x 61.5mm
  • 68.3mm x 60mm
  • 60mm x 60mm
• Designed for 10mm driveline bolts

RF1A Transfer Case Shift Shaft Modifications

Any RF1A transfer case being mated to an L-series transmission or using a V6 adapter will require shortened shift shafts. The shift rails from early RF1A cases are already shorter, but later model rails will need modification.

Shift Rail Shortening Procedure

For later-model RF1A cases, shorten the shift rails as follows:

• 2WD/4WD Rail: Cut to 6-7/8″ total length, measuring from the rear of the rail forward.
• High/Low Rail: Cut to 5-1/4″ total length, measuring from the rear of the rail forward.

Current Shop Practice

• All top-shift cases are being cut unless confirmed not to be used behind an L-series transmission or V6 adapter.

On-Vehicle Rail Cutting (Not Recommended)

• It is possible to cut the rails on an assembled case.
• This can be done by shifting the rail to its forward-most position and cutting as close to the case as possible.
• However, this method is not recommended due to potential complications.

Common Transmissions Mated to the RF1A Transfer Case

• L43, L45, L50, L52 Top shift
• G52, G54 4-1/2 forward shift
• W56 A or B Top shift

• W56 C, D or E 4”forward shift
• R151F 4-1/2 forward shift

• R150F using an adapter plate, (requires shift rail modifications)