Heavy Duty 4x4 Transfer Case Guide, KTC.3000
How to Choose a Heavy Duty 4x4 Transfer Case
Quick answer: A heavy duty 4x4 transfer case takes the rotation from the transmission and sends it to the front and rear axles. For a heavy duty truck, mining vehicle or fire fighting truck on an extra heavy duty 4x4 chassis, choose a unit rated above the torque that reaches it from the engine and gearbox, check the speed rating and ratio, match the flanges and mounting, and make sure it switches between 4x4 and 4x2 driving. The Kozmaksan KTC.3000 is a split shaft, pneumatically controlled unit rated at 19,000 to 21,000 Nm. This guide explains how to size, specify and replace one.
In this guide
- What a heavy duty 4x4 transfer case does
- Who needs one
- How to size a transfer case: torque, speed and ratio
- 4x4 and 4x2 driving, pneumatic control and sensors
- Flanges, connections and dimensions
- Replacing a unit that is hard to source
- How the KTC.3000 compares with other heavy duty units
- Which Kozmaksan transfer case fits your vehicle?
- Common mistakes
- Frequently asked questions
1. What a heavy duty 4x4 transfer case does
On a 4x4 truck the transmission has one output, but the vehicle needs power at two axles. The transfer case passes the rotation from the transmission side to the differential side. On extra heavy duty trucks it carries a very large share of the drivetrain load, so its torque rating, gears, shafts and seals decide how long the truck keeps working. The KTC.3000 uses split shaft mounting and is built with extra-powerful gears, shafts, rotary parts and sealing equipment for any condition.
2. Who needs one
- Heavy duty truck builders, converters and fleet owners who need a custom transfer case for an extra heavy duty 4x4 truck.
- Mining fleets and mining vehicle builders that run extra heavy duty 4x4 vehicles and need a new or replacement transfer case.
- Fire fighting truck builders and municipal fire services working on extra heavy duty 4x4 chassis.
- Fleet and workshop managers looking for a unit that is hard to source.
3. How to size a transfer case: torque, speed and ratio
- Find the maximum torque and speed that reach the transfer case from the engine and gearbox.
- Compare them with the data sheet ratings below. Check torque and speed together, because the two limits apply to different ports.
- Check the ratio. The data sheet lists a ratio of 1.1 for outputs 2 and 3.
- Leave a safety margin for heavy duty and peak loads.
| KTC.3000 data sheet | Max. torque | Max. speed | Ratio |
|---|---|---|---|
| Port 1 (main input) | 19,000 Nm | 3,100 rpm | - |
| Ports 2 and 3 (main outputs) | 21,000 Nm | 2,800 rpm | 1.1 |
| Other KTC.3000 data | Value |
|---|---|
| Vehicle type | Extra heavy duty 4x4 vehicles |
| Mounting type | Split shaft |
| Control type | Pneumatic |
| Weight | 250 kg |
| Data sheet revision | Rev. 00, 01.11.2021 |
4. 4x4 and 4x2 driving, pneumatic control and sensors
The KTC.3000 lets the vehicle switch between 4x4 and 4x2 driving, so the driver can choose the drive mode that suits the ground and the load. Control is pneumatic. The data sheet shows a 4x4 drive sensor, an oil indicator, a temperature sensor (R1/2"-14), an air vent plug and an oiling pump.
5. Flanges, connections and dimensions
- Main input and main outputs: ISO 7647, ISO 7646 and ISO 8667, 8.5c yoke standard flange.
- Pump housing option: SAE B, 13T.
- Dimensions from the drawing: about 1008 mm high, 531 mm long (transmission side to differential side) and 460 mm wide.
- Check the clearance on your chassis before you order.
6. Replacing a unit that is hard to source
To confirm that a replacement fits, send us:
- The nameplate or a photo of the old unit
- Flange types and mounting dimensions
- Transmission and axle details
- Engine torque and the speed at the transfer case
- Your delivery country
Replacing a Marmon-Herrington T60? Our product page lists the KTC.3000 as equivalent to the T60. Marmon-Herrington's T-60 service manual describes the unit as an as-needed all-wheel-drive transfer case for off-road use and does not publish a torque rating, so a number-for-number comparison is not possible. Send us the nameplate, flange sizes and mounting dimensions of your T60 and we will check the fit with you.
7. How the KTC.3000 compares with other heavy duty units
Buyers who need a heavy duty transfer case usually compare published torque ratings, speed limits, housing material, weight and mounting. The table shows published figures for single-ratio (1:1) heavy duty units from other manufacturers, with the KTC.3000 for reference. Manufacturers state ratings under their own conditions (continuous, input or momentary), so use the table as a guide and confirm every detail for your vehicle.
| Unit | Torque as published | Speed as published | Ratio | Other published details |
|---|---|---|---|---|
| Kozmaksan KTC.3000 | 19,000 Nm (port 1); 21,000 Nm (ports 2 and 3) | 3,100 rpm (port 1); 2,800 rpm (ports 2 and 3) | 1.1 (ports 2 and 3) | Split shaft, pneumatic control, 250 kg, SAE B pump housing option |
| Meritor MTC3112 | 12,000 lb-ft (16,270 N·m) | 3,700 rpm input | 1:1 | Aluminum housing |
| Meritor MTC3116 | 15,600 lb-ft (21,150 N·m) | 2,850 rpm input | 1:1 | Cast iron housing |
| Cotta TR2226 | 17,000 lb-ft (about 23,050 N·m) maximum input torque | 2,800 rpm maximum, short duration only | 1:1 | Three-gear unit with precision-ground helical gears; direct mount to Allison 4000 series; SAE C, D and E pump pads; 1,400 lbs |
The KTC.3000 rating of 19,000 to 21,000 Nm sits in the same band as the Meritor MTC3116 (21,150 N·m) and above the MTC3112 (16,270 N·m). The Cotta TR2226 is a different design, with a higher maximum input rating and a much higher weight, so the units suit different installations. A rating alone does not decide the choice: speed, ratio, housing, mounting, flanges and duty cycle matter just as much. Send us your engine torque, gearbox model, flange details and duty cycle and we will tell you whether the KTC.3000 suits your vehicle.
Need a low range as well? If your vehicle needs a two-ratio transfer case, see the Kozmaksan KTC.900 for 8 to 12 ton vehicles, or tell us your requirement.
8. Which Kozmaksan transfer case fits your vehicle?
| Model | Vehicle class and use | Max torque | Key points |
|---|---|---|---|
| KTC.3000 | Extra heavy duty 4x4 vehicles; heavy duty trucks, mining vehicles, fire fighting trucks | 19,000-21,000 Nm | Split shaft, pneumatic control, switches between 4x4 and 4x2, ISO yoke flanges |
| KTC.900 | 8-12 ton medium-duty 4x4; ARFF, fire fighting, military vehicles | 6000 Nm continuous (main drive) | Two ratios, idle gear, neutral gear, differential lock, direct coupling to Allison 1000-2000 series |
| KTC.302 | Off-road vehicles and railway line maintenance vehicles | 1700 Nm | Differential lock, PTO output, split shaft mounting, pneumatic control, aluminium body, 80 kg |
| KTC.301 | Off-road vehicles and railway line maintenance vehicles | 1700 Nm | Differential lock, split shaft mounting, pneumatic control, aluminium body, 68 kg |
Need power at three axles? See our 6x6 transfer cases: KTC.6000 for ARFF trucks and KTC.6001 for heavy duty trucks. You can also browse the full Kozmaksan transfer case range.
9. Common mistakes
- Choosing by vehicle name instead of by the torque and speed that reach the transfer case
- Checking torque but not the speed limit of the port
- Skipping the flange, mounting and clearance check on a replacement
- Forgetting the sensors and pneumatic control connections at the order stage
- Not sending the nameplate when replacing a hard-to-source unit
10. Frequently asked questions
What vehicle class is the KTC.3000 made for?
Extra heavy duty 4x4 vehicles. The data sheet and product page list heavy duty trucks, mining vehicles and fire fighting trucks as the designed applications.
What is its maximum torque?
19,000 Nm at port 1 and 21,000 Nm at ports 2 and 3, according to the data sheet.
How is it mounted and controlled?
Split shaft mounting with pneumatic control.
Can the vehicle switch between 4x4 and 4x2?
Yes. A 4x4 drive sensor is available.
Which flanges does it use?
ISO 7647, ISO 7646 and ISO 8667, 8.5c yoke standard flange on the main input and outputs. An SAE B 13T pump housing is an option.
What does it weigh?
250 kg according to the data sheet.
What if my vehicle is lighter?
See the KTC.900 for 8 to 12 ton medium-duty vehicles, or tell us your vehicle and we will recommend a model.
Do you make 6x6 transfer cases?
Yes. See the KTC.6000 for ARFF trucks and the KTC.6001 for heavy duty trucks.
Do you ship worldwide?
Yes. Send your truck details and delivery country for a quote.
About the manufacturer
Kozanoğlu Kozmaksan Ltd. Şti. has manufactured power take-offs, transfer cases, pumps and hydraulic equipment since 1972 and ships to customers worldwide. The KTC.3000 product page also shows a product video, assembly pictures and a mining application photo.
Next step
See the product page, download the KTC.3000 catalogue and request a quote: Heavy Duty 4x4 Transfer Case KTC.3000. Looking for another vehicle class? Browse the full Kozmaksan transfer case range.
Technical figures for the KTC.3000 are from the Kozmaksan KTC.3000 data sheet (Rev. 00, 01.11.2021). Meritor, MTC, Marmon-Herrington and Cotta are trademarks of their owners; their figures come from the manufacturers' published information (Cummins for Meritor, the Cotta TR2226 data sheet, and the Marmon-Herrington T-60 service manual) and are shown for comparison only.
