Automated manual transmission
Used PACCAR Automated Transmissions (TX-12)
The PACCAR Automated Transmission, known as the TX-12, is a 12-speed automated manual used in Kenworth and Peterbilt trucks with PACCAR MX engines. Send us your label and VIN details and we search supplier sources for a matching used unit.
PACCAR Automated Transmission at a glance
- Type
- Automated manual (AMT), two-pedal
- Forward speeds
- 12
- Versions
- Direct drive and overdrive
- Typical applications
- Kenworth T680 and Peterbilt 579 and similar models, usually paired with PACCAR MX-13 or MX-11 engines
Identification tag
How to identify your PACCAR TX-12
The transmission has an identification label on the housing with the model designation, serial number and part number. Note whether it is a direct-drive or overdrive version.
Kenworth and Peterbilt build records tied to the VIN show the original transmission, engine and axle specification, so include the full VIN with your request.
01Automated manual, not automatic
The TX-12 is a gearbox with an automated clutch and computer-controlled shifting. It has no torque converter. Do not confuse it with torque-converter automatics such as an Allison.
02TX-12 vs. TX-8 and other PACCAR units
PACCAR also offers the TX-8 for lighter trucks. These are different transmissions and are not interchangeable. This page covers the TX-12; if your truck has a TX-8, tell us and we will search for that unit instead.
03Control unit, software and harness
The TX-12 relies on a transmission control unit that communicates with the PACCAR engine and truck electronics. A replacement may need software or parameter setup using dealer-level tools. Make sure the connectors and harness versions match your truck.
04Ratios, PTO and clutch
Match the direct-drive or overdrive version to keep cruise RPM and axle ratio aligned. If your truck uses a PTO, confirm the replacement supports it, and note whether you need the clutch or actuator.
05Core and exchange
Core charges or exchange terms may apply depending on the supplier. If they do, they are confirmed on your quote before you commit, along with availability and freight.
Configuration
What we'll ask to match your unit
- What model designation, serial number and part number are on the label?
- Is it direct drive or overdrive?
- What is the truck make, model, year and VIN?
- Is it paired with an MX-13 or MX-11?
- Does the truck use a PTO?
- Do you need the clutch, actuator or control unit too?
FAQ
PACCAR Automated Transmission questions
Is the PACCAR TX-12 an automatic?
No. It is an automated manual transmission. It uses a clutch and gears with automated shifting rather than a torque converter.
Which trucks use the PACCAR TX-12?
It is found in Kenworth and Peterbilt trucks, typically with PACCAR MX-13 or MX-11 engines. Your VIN confirms what your truck was built with.
Is the TX-12 related to the Eaton Endurant?
PACCAR developed its automated transmission with Eaton's involvement, and it shares design elements with the Endurant. It is still identified and sourced as its own unit, so we search by the PACCAR part number.
Will a used TX-12 need programming?
Often some setup is needed so the transmission and engine communicate correctly. A Kenworth or Peterbilt dealer or equipped shop can handle it.
Do you stock PACCAR transmissions?
We are an independent sourcing company. We search supplier sources nationwide and confirm availability and freight on your quote.
Ready when you are
Need a PACCAR Automated Transmission? Send the tag number.
Have your engine serial number or transmission tag and VIN handy. If you don't, we'll help you find them.
Commercial-Engines.com is an independent supplier of used commercial truck engines and transmissions. Manufacturer names, model names and part numbers are used for identification only and do not imply affiliation with, or endorsement by, any manufacturer. Read the full disclaimer.