How to Fix Common DT12 Transmission Problems? (5+ Warning Signs)

In this brief guide, we are going to provide you with common problems with DT12  transmission and what you can do to rectify these problems before they worsen.

DT12 has automated manual transmission and does not require any manual input to shift gears while driving. Various sensors and mechatronic systems work in coordination to shift gears automatically. 

Automated manual transmissions have a global reputation for quality, reliability and durability. However, there are many problems with automated manual transmissions and we’ll tell you why and how you can solve them

What are the common problems with DT12 transmission?

Some of the most common problems with DT12  transmission are:

  • Difficulty shifting
  • Transmission slippage
  • Incorrect gear ratio
  • Shift solenoid malfunction
  • Torque Converter Clutch Malfunction

Why is Difficulty shifting a problem with DT12 transmissions?

You would want a seamless and easy shift even at low throttle input, so if your DT12 transmission is shifting harshly or with difficulty even at low speed then there is definitely a problem.

What are the signs of this problem with the DT12  transmission?

You would immediately notice and sense if the DT12 transmission is shifting with difficulty from one gear to another as this is one of most important issues with D12.

How to solve this DT12  transmission problem?

Firstly try replacing the transmission pressure sensor, if that doesn’t work then check for an oil leak in the servo assembly of the particular gear. These are primarily two fixes for this problem.

Why is Transmission slippage a problem with DT12   transmissions?

The DT12 transmission system is not designed to slip and if you are experiencing slippage then it could cause slow response or further damage to the transmission system. So, it is definitely a sign of a problem with the mechanical components of the transmission.

What are the signs of this problem with the DT12  transmission?

You will be able to hear the gear slip while driving and this would be a good sign if there is slipping. Also, an error code will be displayed if you use a diagnostic tool.

How to solve this DT12  transmission problem?

The solenoids of the two gears might be worn out and need to be replaced. Also, there is a chance that these solenoids might also be broken. Rarely, complete mechanical failure occurs with these transmissions.

Why is Incorrect gear ratio a problem with DT12 transmissions?

If the DT12 transmission is with an incorrect gear ratio then it can cause anything from shift solenoid problems to transmission fluid problems.

What are the signs of this problem with the DT12 transmission?

P0730 is the code that will be shown if there is an incorrect gear ratio with the DT12 transmissions. This is a generic code which you will get using OBD-II for your transmission.

How to solve this DT12 transmission problem?

Wires connecting sensors to the transmission control module and other electrical connections should be inspected and any damaged or corroded wires in and near the transmission control module should be repaired or replaced to fix this issue.

Why is Shift solenoid malfunction a problem with DT12  transmissions?

Shift solenoid malfunction means there is a problem with the gear shifting. A DT12 transmission changes gear by directing pressurized transmission fluid to move clutches and bands around. The computer controls all of this with little spring-loaded devices called solenoids.

What are the signs of this problem with the DT12 transmission?

P0750 is the code that will be shown if there is a shift solenoid malfunction with the DT12 transmissions. This is a generic code which you will get using OBD-II for your transmission.

How to solve this DT12   transmission problem?

Some common solutions are changing the transmission fluid and filter or replacing faulty solenoids. Also you can repair or replace a faulty transmission pump.

Why is Torque Converter Clutch Malfunction a problem with DT12 transmissions?

If your torque converter or if you are not getting the desired response when you release the brake and press the throttle pedal then you are most definitely experiencing torque converter engagement or disengagement problems.

What are the signs of this problem with the DT12  transmission?

First sign would be that you are unable to stop the car when releasing the throttle pedal for disengagement problem and secondly for engagement from even if you press too much throttle the car will not move forward.

How to solve this DT12  transmission problem?

If the clutch of the torque converter is worn out then you need to replace it or else the solenoid might be broken which also might need replacing. In the worst case the entire assembly needs to be replaced if the state of the torque converter is beyond repair.

How to precisely diagnose these common problems in DT12  transmission?

If you need to precisely diagnose these common problems then you need to use a diagnostic tool which is software based and can be connected to the vehicle electronic system as DT12  transmission fully electronically controlled automatic transmission.

How to prevent getting these problems in the first place?

To prevent these problems, you need to change the DT12  transmission oil as per the manual or when it is too dirty. This is the easiest and most effective way to take care of your vehicle transmission and also drive your vehicle in a recommended way. 

FAQs: DT12 transmission problems

What is a DT12 transmission?

The DT12 is a 12-speed non-synchronized automated manual transmission with pneumatic X-Y shift and clutch actuators. It features a single countershaft and an aluminum housing to minimize weight. It will be available in two input-torque ratings: 2,050 pounds-feet (789 pounds dry weight) and 1,650 pounds-feet (646 pounds).

Can you put a PTO on a DT12 transmission?

Yes, both the Direct Drive and OverDrive DT12 transmissions are available for order with a proprietary rear mounted PTO on original Freightliner Cascadia models with or without the Evolution aerodynamic package, and Western Star 5700XE models.

Conclusion

In this brief guide, we have provided you with common problems with DT12 transmission and what you can do to rectify these problems before they worsen.

If you have any questions or comments please let us know.

Citations:

https://www.thetruckersreport.com/truckingindustryforum/threads/cascadia-dt12-transmission-problem.1261488/