• JP Magazine
  • Dirt Sports + Off-Road
  • 4-Wheel & Off-Road
  • Four Wheeler

Common Transfer Cases Guide - Picking High And Low Ranges

Posted in How To on May 1, 2010 Comment (0)
Share this
Photographers: Various Manufacturers

Every 4WD vehicle uses a transfer case to split the drive coming from the transmission into two outputs, one directed to the front axle and one directed to the rear axle. Most transfer cases that we are familiar with are two-speed versions, having a high-range and low-range gear set.

The high-range is most often a 1:1 ratio. That is to say that for every revolution of the transmission output shaft, the front and rear transfer case outputs rotate one revolution. Factory low-range ratios can vary from about 2:1 to about 4:1. This means that the road speed in low-range is reduced by a half or by a quarter. With this reduction in speed we gain an increase in torque by the same factor.

Transfer cases have come in both gear drive and chain drive versions. Typically a chain drive case is a bit quieter, but a gear drive case is most often stronger and does not suffer from chain wear, which requires periodic replacement. Low-range reductions come in two flavors as well: gear-to-gear reduction or a planetary gear reduction assembly.

Here we've compiled a list of specs for many of the more common transfer cases that off-roaders use, swap, or modify. We've tried to included input/output shaft spline counts, specify the types of driveshaft mating, and give some idea as to the extent of aftermarket support available to these T-cases (ranging from low to high).

BW 1339 (Quadratrac limited slip)
Manufacturer: Borg Warner
Number of speeds: Two (full-time 4WD)
High: 1:1
Low: 2.57:1
Case (or housing) material: Aluminum
Front output drive type: Chain (passenger side drop)
Availability or aftermarket parts and support: Medium - Mile Marker part-time conversion & overdrive kit
Input spline count: 10
Rear yoke: Fixed
Planetary gear: Yes, four-pinion
Available U-joint sizes for yokes: 1310
Flange or slip yoke eliminator available: n/a
Output shaft spline count: 10
Shifter type: Mechanical
Found in: '73-to-'79 fullsize Jeep and CJ7s (behind AMC TH400)

BW 1350
Manufacturer: Borg Warner
Number of speeds: Two
High: 1:1
Low: 2.48:1
Case (or housing) material: Aluminum
Front output drive type: Chain (driver side drop)
Availability or aftermarket parts and support: Low
Rear yoke: Fixed
Planetary gear: Yes
Shifter type: Mechanical or electrical
Found in: '83-to-'93 Ford Ranger, '84-to-'90 Bronco II & Explorer

BW 1356
Manufacturer: Borg Warner
Number of speeds: Two
High: 1:1
Low: 2.72:1
Case (or housing) material: Magnesium
Front output drive type: Chain (driver side drop)
Availability or aftermarket parts and support: Low
Input spline count: 31
Rear yoke: Slip or Fixed
Planetary gear: Yes
Available U-joint sizes for yokes: 1330
Flange or slip yoke eliminator available: Yes
Output shaft spline count: 31
Shifter type: Mechanical or electrical
Speedo output: Cable port pre-'92 only
Length: ~18.5 inches (mount face-to-yoke center)
Commonly found in: '87-to-'97 Ford F150, F250, F350, & Bronco

Dana/Spicer 18
Manufacturer: Dana-Spicer
Number of speeds: Two
High: 1:1
Low: 1.97:1 or 2.46:1
Case (or housing) material: Cast iron
Front output drive type: Gear (driver side drop)
Availability or aftermarket parts and support: High - Saturn overdrive, Novak Intermediate Shaft Kit, Tera Low 3.15:1 kit
Input spline count: 6 or 10
Rear yoke: Fixed (Jeep version had drum parking brake)
Planetary gear: No
PTO output: Yes
Available U-joint sizes for yokes: 1310
Output shaft spline count: 26
Shifter type: Mechanical
Weight: ~80 pounds
Length: ~8.5 inches (mount face-to-flange face)
Commonly found in: '71-and-earlier Jeep, Willys vehicles, Ford GPW, IH Scouts

Dana 20
Manufacturer: Dana-Spicer
Number of speeds: Two
High: 1:1
Low: 2.03:1 or 2.34:1 or 2.46:1
Case (or housing) material: Cast iron
Front output drive type: Gear (driver side drop)
Availability or aftermarket parts and support: High - Tera Low 3.15:1 low-range, twin stick with old Dana 18 or aftermarket parts, 32-spline Advance Adapters rear output
Input spline count: 6 or 10
Rear yoke: Fixed
Planetary gear: No
PTO output: Yes
Available U-joint sizes for yokes: 1310
Output shaft spline count: 10 or 26
Shifter type: Mechanical
Weight: ~80 pounds
Length: ~10.5 inches (mount face-to-yoke center)
Commonly found in: '72-to-'79 CJs, '67-to-'73 Jeepsters, '63-to-'70 Wagoneer/Gladiator/J-Trucks (and '71-to-'79 with manual transmissions), '66-to-'77 Ford Broncos, '65-to-'79 IH Scouts (known as TC-145), some GM 1/2 ton trucks and Blazers/Jimmys

Dana 300
Manufacturer: Dana-Spicer
Number of speeds: Two
High: 1:1
Low: 2.62:1
Case (or housing) material: Cast iron
Front output drive type: Gear (driver side drop)
Availability or aftermarket parts and support: High - Twin stick setup, JB Conversions Lo-Max 4.0:1 low-range for the increase in strength where needed, and heavy-duty 32-spline front and rear outputs
Input spline count: 23
Rear yoke: Fixed
Planetary gear: No
Available U-joint sizes for yokes: 1310
Output shaft spline count: 26
Shifter type: Mechanical
Weight: ~86 pounds
Length: ~10.5 inches or 11.625 inches (mount face-to-yoke center)
Commonly found in: '80-to-'86 Jeep CJs, 1980 IH Scout

Nissan TX10A
Number of speeds: Two
High: 1:1
Low: 2.02:1
Case (or housing) material: Aluminum
Front output drive type: Gear (driver side drop)
Availability or aftermarket parts and support: Medium - Calmini 3.92:1 gearset, Automotive Customizers 3.6:1 gearset
Input spline count: 24 (I-4) or 30 (V-6)
Rear yoke: Slip
Planetary gear: No
Flange or slip yoke eliminator available: Yes
Output shaft spline count: 30
Shifter type: Mechanical
Length: ~18 inches (mount face-to-seal)
Commonly found in: Mid '86-to-'04 Truck, pre '96 Pathfinders, Xterras, Frontiers

NP203
Manufacturer: New Process Gear
Number of speeds: Two
High: 1:1
Low: 1.96:1
Case (or housing) material: Cast iron
Front output drive type: Chain (driver or passenger side drop)
Availability or aftermarket parts and support: High - part-time conversion kits
Input spline count: 10, 27, or 32
Rear yoke: Fixed
Planetary gear: No
Available U-joint sizes for yokes: 1310, 1310-CV (front), CV flange (front)
Output shaft spline count: 32
Shifter type: Mechanical
Weight: 165 pounds
Length: ~21.5 inches (mount face-to-yoke center)
Commonly found in: '71-to-'80 fullsize Ford, Chevy and Dodge 4WDs

NP208 (pictured) / 209 / 228 / 229
Manufacturer: New Process Gear
Number of speeds: Two
High: 1:1
Low: 2.69:1
Case (or housing) material: Aluminum
Front output drive type: Chain (driver and passenger side drop)
Availability or aftermarket parts and support: Low
Input spline count: 23, 27, 31 or 32
Rear yoke: Fixed or Slip
Planetary gear: Yes (six-pinion)
Available U-joint sizes for yokes: 1310, 1330
Flange or slip yoke eliminator available: Yes
Shifter type: Mechanical
Weight: ~79 pounds
Length: ~18 inches (mount face-to-yoke center)
Commonly found in: '80s fullsize Jeep Cherokee & fullsize domestic trucks

NP205
Manufacturer: New Process Gear
Number of speeds: Two
High: 1:1
Low: 1.96:1
Case (or housing) material: Cast iron
Front output drive type: Gear (driver or passenger side drop)
Availability or aftermarket parts and support: High - twin stick conversion, underdrive, JB Conversions LoMax 3:1 gearset, doubler setups
Input spline count: 10, 23, 27, 29, 31 or 32
Rear yoke: Slip ('80-and-newer) or fixed ('79-or-older)
Planetary gear: No
PTO output: Yes
Available U-joint sizes for yokes: 1310, 1330, 1350, 1410 or 1310 CV
Flange or slip yoke eliminator available: Yes (flange)
Output shaft spline count: 32
Shifter type: Mechanical
Weight: ~138 pounds
Length: ~13 inches or 16 inches (mount face-to-yoke center)
Commonly found in: '71-to-'80 fullsize Ford, Chevy and Dodge 4WDs, IH trucks

NP205 Divorced
Manufacturer: New Process Gear
Number of speeds: Two
High: 1:1
Low: 1.96:1
Case (or housing) material: Cast Iron
Front output drive type: Gear (driver or passenger side drop)
Availability or aftermarket parts and support: High - twin stick conversion, underdrive, JB Conversions LoMax 3:1 gearset, doubler setups
Input spline count: N/A (input yoke)
Rear yoke: Fixed
Planetary gear: No
PTO output: Yes
Available U-joint sizes for yokes: 1310, 1330, 1350, 1410 or 1310 CV
Output shaft spline count: 32
Shifter type: Mechanical
Weight: ~140 pounds
Commonly found in: '70s fullsize Ford, Chevy and Dodge 4WDs

NP231 / NP231HD
Manufacturer: New Process Gear
Number of speeds: Two
High: 1:1
Low: 2.72:1
Case (or housing) material: Aluminum
Front output drive type: Chain (driver or passenger side drop)
Availability or aftermarket parts and support: Medium - heavy-duty slip yoke eliminator kits, Novak mechanical shifter
Input spline count: 21, 23, 26 or 27
Rear yoke: Slip
Planetary gear: Yes (three-pinion)
Available U-joint sizes for yokes: 1310
Flange or slip yoke eliminator available: Yes
Output shaft spline count: 27
Shifter type: Vacuum
Weight: ~70 pounds (~80 pounds for HD version)
Commonly found in: '88-to-'97 Jeep XJ, YJ, '86-and-up Jeep TJ, '88-and-up Dodge Dakota, '88-to-'97 GM T-Series

NP241 / NP241D / NP241HD
Manufacturer: New Process Gear
Number of speeds: Two
High: 1:1
Low: 2.72:1
Case (or housing) material: Aluminum
Front output drive type: Chain (driver or passenger side drop)
Availability or aftermarket parts and support: Medium
Input spline count: 23, 27, 29, 31 and 32
Rear yoke: Slip
Planetary gear: Yes (six-pinion)
Flange or slip yoke eliminator available: Yes
Shifter type: Mechanical
Commonly found in: '89-and-newer GM 1/2 & 3/4 ton trucks & SUVs, '88-and-newer Dodge 1/2-&-3/4-ton trucks, Jeep Rubicon

NP241OR (Rock-Trac)
Manufacturer: New Process Gear
Number of speeds: Two
High: 1:1
Low: 4:1
Case (or housing) material: Aluminum
Front output drive type: Chain (driver side drop)
Availability or aftermarket parts and support: Medium - 2 low shift kit, Novak shifter assembly
Input spline count: 23
Rear yoke: Fixed
Planetary gear: Yes
Shifter type: Mechanical
Weight: ~90 pounds
Commonly found in: '03-and-newer Wranglers (some)

NP261 / NP263
Manufacturer: New Process Gear
Number of speeds: Two
High: 1:1
Low: 2.76:1
Case (or housing) material: Magnesium
Front output drive type: Chain (driver side drop)
Availability or aftermarket parts and support: Low
Input spline count: 27 or 32
Rear yoke: Slip
Planetary gear: Yes (six-pinion)
Flange or slip yoke eliminator available: Yes
Shifter type: Mechanical (NP261), Electrical (NP263)
Commonly found in: '99-to-current GM 1/2- and 3/4-ton trucks, Suburban, Sierra, Silverado

NP271 / NP273
Manufacturer: New Process Gear
Number of speeds: Two
High: 1:1
Low: 2.72:1
Case (or housing) material: Aluminum
Front output drive type: Chain (driver or passenger side drop)
Availability or aftermarket parts and support: Low
Input spline count: 24, 31, or 34
Rear yoke: Fixed
Planetary gear: Yes (six-pinion)
Shifter type: Mechanical (NP271), Electrical (NP273)
Commonly found in: '98-and-up Ford F-250 and heavier Super Duty, Dodge trucks '03-and-newer

Rockwell T221N
Manufacturer: Rockwell-Standard Corporation
Number of speeds: Two
High: 1:1
Low: 1.94:1
Case (or housing) material: Cast iron
Front output drive type: Gear (passenger side drop)
Availability or aftermarket parts and support: Low
Input spline count: 10
Rear yoke: Fixed
Planetary gear: No
Output shaft spline count: 10
Shifter type: Mechanical
Commonly found in: Some '69-and-older Chevy trucks

Suzuki Samurai
Number of speeds: Two
High: 1:1
Low: 2.268:1
Case (or housing) material: Aluminum
Front output drive type: Gear (passenger side drop)
Availability or aftermarket parts and support: High - Multiple available low gear sets
Input spline count: 26
Rear yoke: Fixed flange (passenger side drop)
Planetary gear: No
Shifter type: Mechanical
Length: ~9 inches mount face-to-flange
Commonly found in: '86-to-'95 Suzuki Samurai

Toyota RF1A
Manufacturer: Aisin Seiki
Number of speeds: Two
High: 1:1
Low: 2.28:1
Case (or housing) material: Aluminum
Front output drive type: Gear (passenger side drop)
Availability or aftermarket parts and support: High - Dual/triple case kits, low gears sets, twin stick kits, rear disconnect kits, chromoly output shaft
Input spline count: 21 or 23
Rear yoke: Fixed flange
Planetary gear: No
Output shaft spline count: 27
Shifter type: Mechanical and electrical
Length: ~12.75 inches (mount face-to-flange)
Commonly found in: Various '79-to-'95 Toyota Truck and '84-to-'85 4Runner

Toyota VF1A/VF2A
Manufacturer: Aisin Seiki
Number of speeds: Two
High: 1:1
Low: 2.57:1
Case (or housing) material: Aluminum
Front output drive type: Gear (passenger side drop)
Availability or aftermarket parts and support: Medium - Dual case kits, adapters
Input spline count: 23 or 26
Rear yoke: Fixed flange
Planetary gear: Yes
Output shaft spline count: 27
Shifter type: Mechanical or electrical
Length: ~12.5 inches (mount face-to-flange)
Commonly found in: Various '84-to-'95 Toyota Truck/4Runner/T-100

Toyota Land Cruiser
Number of speeds: Two
High: 1:1Low: 2.31:1 (pre '74), 1.99:1 (1974), 1.96:1
('75-'80), 2.28:1 ('80 -'83/'84), 1.96:1 ('83 and up)
Case (or housing) material: Aluminum
Front output drive type: Gear
Availability or aftermarket parts and support: Medium (AA case replacement)
Input spline count: 10 (early models) or 16
Rear yoke: Fixed flange
Planetary gear: No
PTO output: Yes
Output shaft spline count: 27
Shifter type: Mechanical
Length: ~9 5/8 inches (mount face-to-flange)
Commonly found in: '63-to-'80s Toyota Land Cruisers

Toyota VF2AM/VF2BM
Manufacturer: Aisin Seiki
Number of speeds: Two
High: 1:1
Low: 2.57:1
Case (or housing) material: Aluminum
Front output drive type: Chain (driver side drop)
Availability or aftermarket parts and support: Medium - Dual case kits, adapters
Input spline count: 23 or 26
Rear yoke: Fixed flange
Planetary gear: Yes
Output shaft spline count: 27
Shifter type: Mechanical or electrical
Commonly found in: '95-and-newer Toyota Tacoma/4Runner/Tundra

Aftermarket Complete Transfer Cases Or Kits

Atlas II
Manufacturer: Advance Adapters
Number of speeds: Two
High: 1:1
Low: 2.0:1, 3.0:1, 3.8:1, 4.3:1, 5.0:1, or 6.0:1
Case (or housing) material: 356-T6 Heat Treated Aluminum
Front output drive type: Gear (driver or passenger side drop)
Input spline count: Multiple choices
Rear yoke: Fixed
Planetary gear: No
Available U-joint sizes for yokes: 1310, 1310-CV, A1330-CV, 1350, 1350-CV, 1410
Flange available: Yes (1300, 1400 or JK Flange)
Output shaft spline count: 32 spline
Shifter type: Mechanical or cable
Weight: 110 pounds
Length: 11.8 inches (short tail) or 13.8 inches (long tail)

Atlas 4-Speed
Manufacturer: Advance Adapters
Number of speeds: Four
High: 1:1
Low: 2.0:1, 2.72:1, & 5.44:1 or 2.72:1, 3.8:1, &10.34:1
Case (or housing) material: 356-T6 Heat Treated Aluminum
Front output drive type: Gear (driver or passenger side drop)
Input spline count: Multiple choices
Rear yoke: Fixed
Planetary gear: Yes, six-pinion helical (for secondary reduction)
Available U-joint sizes for yokes: 1310, 1310-CV, A1330-CV, 1350, 1350-CV, 1410
Flange available: Yes (1300, 1400 or JK Flange) Output shaft spline count: 32 spline
Shifter type: Mechanical or cable
Weight: 125 pounds
Length: 15 inches (short tail) or 17 inches (long tail)

Orion
(Replacement housing/gears for Land Cruisers built between 1963 and July 1980)
Distributor: Advance Adapters
Number of speeds: Two
High: 1:1
Low: 3:1 or 4:1
Case (or housing) material: Cast Iron
Front output drive type: Gear (passenger side drop)
Input spline count: 10 or 16
Rear yoke: Fixed
Planetary gear: No
PTO output: Yes
Output shaft spline count: Stock
Shifter type: Mechanical
Length: Stock

Mini Monster
Manufacturer: STaK Up Marketing
Number of speeds: Two or three
High: 1:1
2-Speed Low: 3.78:1, 4.29:1 or 5.22:1
3-Speed Low: 2.10:1 & 3.75:1 or 2.43:1 & 4.33:1 or 3.05:1 & 5.44:1
Case (or housing) material: Cast 356 Alloy Aluminum
Front output drive type: Gear (driver or passenger side drop)
Input spline count: Multiple choices
Rear yoke: Fixed
Planetary gear: No
Available U-joint sizes for yokes: 1310, 1310-CV, 1350, 1350-CV, 1410
Flange available: Yes
Output shaft spline count: 32
Shifter type: Mechanical
Weight: 110 pounds (two-speed), 130 pounds (three-speed)
Length: ~13 inches (mount surface to yoke center - depends on yoke)

Monster B-Box 3-Speed
Manufacturer: STaK Up Marketing
Number of speeds: Three
High: 1:1
Low: 2.05:1 & 3.75:1 or 2.43:1 & 4.33:1 or 3.05:1 & 5.44:1
Case (or housing) material: Cast 356 Alloy Aluminum
Front output drive type: Gear (driver or passenger side drop)
Input spline count: Multiple choices
Rear yoke: Fixed
Planetary gear: No
Available U-joint sizes for yokes: 1310, 1310-CV, 1350, 1350-CV, 1410
Flange available: Yes
Output shaft spline count: 32
Shifter type: Mechanical
Weight: ~160 pounds
Length: ~13 inches (mount surface to yoke center - depends on yoke)

Monster Box
Manufacturer: STaK Up Marketing
Number of speeds: Two or three
High: 1:1
2-Speed Low: 3.75:1, 4.33:1 or 5.44:1
3-Speed Low: 2.15:1 & 3.78:1 or 2.44:1 & 4.29:1 or 2.97:1 & 5.22:1
Case (or housing) material: Cast 356 Alloy Aluminum
Front output drive type: Gear (driver or passenger side drop)
Input spline count: Multiple choices
Rear yoke: Fixed
Planetary gear: No
Available U-joint sizes for yokes: 1310, 1310-CV, 1350, 1350-CV, 1410
Flange available: Yes
Output shaft spline count: 32
Shifter type: Mechanical
Weight: 127 pounds (two-speed), 155 pounds (three-speed)
Length: ~13 inches (mount surface to yoke center - depends on yoke)

D300
Manufacturer: STaK Up Marketing
Number of speeds: Two
High: 1:1
Low: 4:1 (JB Conversions LoMax gears)
Case (or housing) material: Cast 356 Alloy Aluminum
Front output drive type: Gear (driver or passenger side drop)
Input spline count: Multiple choices
Rear yoke: Fixed
Planetary gear: No
Available U-joint sizes for yokes: 1310, 1310-CV, 1350, 1350-CV, 1410
Flange available: Yes
Output shaft spline count: 32
Shifter type: Mechanical
Weight: ~86 pounds
Length: ~10.5-12 inches (mount surface to yoke center - depends on yoke)

Comments

Connect With Us

Newsletter Sign Up

Subscribe to the Magazine

Sponsored Links