Advance Adapters TX2 23TH Crawler Double Bearing - Toyota 1979-95 - 50-5906D
50-5906D
Advance Adapters TX2 Crawler Adapter - 23 Spline Toyota Transfer Case
Unlock extreme crawling capability in your 1979-1995 Toyota truck or 4Runner with the Advance Adapters TX2 Crawler kit. This innovative dual-case adapter allows you to use the front section of your existing Toyota gear-driven transfer case as an additional reduction unit, creating a "doubler" setup that dramatically increases your gear reduction for technical rock crawling and extreme off-road situations.
The TX2 Solution - Double Your Reduction
Running larger tires on a stock drivetrain often leaves you under-geared for technical terrain. The TX2 Crawler adapter solves this by converting the front section of a donor Toyota transfer case into a reduction box that mounts between your transmission and your main transfer case. The result? Exponentially lower crawl ratios that give you ultimate control in the rocks without sacrificing highway drivability.
Heavy-Duty Double Bearing Design
What sets the TX2 apart from single bearing adapters is the robust double bearing coupler system. This design provides:
- Superior Load Distribution: Two roller bearings handle radial loads while a needle bearing manages thrust loads
- Reduced Vibration: Double bearing configuration minimizes vibration and drivetrain harmonics
- Increased Durability: More bearing support means longer life under extreme torque loads
- Smooth Operation: Precision-machined components ensure smooth power transfer
Precision-Engineered Construction
Every TX2 adapter is CNC-machined from 356-T6 heat-treated aluminum alloy—the same material used in high-performance racing components. At just 2.375 inches in length, the adapter adds minimal overall length to the drivetrain while maintaining maximum strength. The compact design minimizes driveline angles and reduces the need for extensive floor modifications.
Complete Kit - Everything Included
This comprehensive kit includes everything you need for installation:
- Adapter housing (356-T6 aluminum)
- Double bearing coupler assembly
- Thrust washer
- Steel ball
- Two roller bearings
- Needle bearing
- Snap rings
- Gaskets (multiple applications covered)
- All fastening hardware
- Detailed installation instructions
23 Spline Application - Fits 1979-1995 Toyota
The 50-5906D kit is specifically designed for Toyota 23-spline gear-driven transfer cases. You can identify your transfer case by:
- Male 23-spline input shaft
- 7 bolts attaching the tailhousing to the transfer case body
This configuration is found in many 1979-1995 Toyota trucks and 4Runners with gear-driven transfer cases. If you have a 21-spline transfer case, use kit 50-5905D instead.
Installation Requirements
Installing the TX2 Crawler requires mechanical knowledge and fabrication skills:
- Donor Transfer Case: You'll need the front section of a compatible Toyota transfer case
- Driveline Modifications: Front and rear driveshafts will require shortening or replacement
- Floorboard Modifications: Some floor cutting and modification is typically required
- Extended Speedometer Cable: Part 716186-C recommended (sold separately)
- Shifter Spacing: Final shifter spacing will be approximately 6.5 inches apart (depending on donor case)
Professional installation is strongly recommended unless you have extensive drivetrain experience.
Transfer Case Shifter Configurations
Depending on your donor transfer case year and model:
- 1979-83 Carbureted / 1985-88 EFI: Shifter on transfer case with 4-bolt cast iron base (3-1/8" x 4-3/8")
- 1984-88 Carbureted / 1986-87 EFI Turbo: Shifter on transmission tailhousing with 4-bolt aluminum base (3-1/4" x 4")
Why Choose a Doubler Setup?
The TX2 Crawler doubler provides:
- Extremely low crawl ratios for technical terrain
- Ability to run larger tires without sacrificing low-end torque
- Maintain highway drivability (keep your overdrive)
- Selectable reduction (engage/disengage as needed)
- Proven Toyota reliability
Advance Adapters Quality
Advance Adapters has been the industry leader in transfer case adapters and drivetrain solutions for over 70 years. Based in California, they manufacture precision-engineered components that are proven in the most demanding off-road applications worldwide. When you buy Advance Adapters, you're getting American-made quality backed by decades of innovation.
Build the Ultimate Crawler
Whether you're building a purpose-built rock crawler, upgrading your trail rig, or creating the ultimate expedition vehicle, the TX2 Crawler adapter is the foundation for extreme low-range capability.
KEY FEATURES:
✅ Double Bearing Design – Superior strength and durability
✅ 356-T6 Heat-Treated Aluminum – Lightweight, high-strength construction
✅ 23-Spline Application – Fits 1979-95 Toyota gear-driven transfer cases
✅ Complete Kit – Housing, bearings, hardware, gaskets, instructions
✅ 2.375" Length – Compact design minimizes drivetrain length
✅ Creates Doubler Setup – Use donor T-case for extreme reduction
✅ CNC-Machined – Precision engineering for perfect fitment
✅ 7-Bolt Transfer Case – Designed for Toyota 23-spline configuration
✅ Made in USA – Advance Adapters quality since 1950s
✅ Proven Design – Thousands installed worldwide
TECHNICAL SPECIFICATIONS:
| Specification | Details |
|---|---|
| Part Number | 50-5906D |
| Manufacturer | Advance Adapters |
| Application | 1979-95 Toyota 23-spline gear-driven T/C |
| Material | 356-T6 heat-treated aluminum alloy |
| Adapter Length | 2.375 inches |
| Spline Count | 23 spline |
| Transfer Case ID | 7-bolt tailhousing, male 23-spline input |
| Bearing Type | Double bearing (2 roller, 1 needle) |
| Country of Origin | Made in USA |
| Weight | Approx. 10-12 lbs (complete kit) |
WHAT'S INCLUDED:
Complete TX2 Crawler Kit:
- TX2 adapter housing casting (51-5909)
- Double bearing coupler - 23 tooth (52-5910)
- Thrust washer/spacer (716182)
- 1/4" steel ball (716182B)
- (2) Sealed roller bearings 209RS (716308)
- Needle bearing (716323)
- Snap rings (716456, 716463)
- Gaskets - multiple applications (716563, 716564)
- Special stud bolts (716065)
- 10mm x 1.25 nuts with 14mm wrench size (720012)
- 10mm flat washers (720015)
- 10mm lock washers (720038)
- Complete installation instructions