Allison transmission problems

In this brief guide, we are going to provide you with the common Allison transmission problems and what are the solutions to these problems.

Allison Transmissions are heavy-duty automatic transmissions and have a global reputation for quality, reliability and durability. However, there are many problems with Allison  transmissions and we’ll tell you  how you can solve them.

What are the common problems with Allison transmission?

Most of the common problems with Allison transmission are:

  • Torque Converter stator failure
  • Shift Valve Body breakage
  • Oil Pump inefficiency
  • Poor longevity of Bushings 
  • Solenoid failure 
  • Differential gear failure

Why is torque converter stator failure a problem with Allison transmissions?

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

What signs are shown by this Allison transmission problem?

There will be specific error codes shown from the diagnostic tool if the torque converter stator has been broken or completely failed. 

What is the solution to this Allison transmission problem?

If the clutch of the torque converter is worn out then you need to replace it or else the stator 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.

Why is shift valve body breakage a problem with Allison transmissions?

Allison shift valves are notorious to seizure or breaking and they will cause problems during shifting speed while driving.

What signs are shown by this Allison transmission problem?

Signs of a bad valve body present as sloppier shifts than when the truck was new, or you could notice being quick to downshift under load.

What is the solution to this Allison transmission problem?

The valve bodies which are seized should be replaced with the new one and you will instantly notice the shifting to be improved.

Why is oil pump inefficiency a problem with Allison transmissions?

The Allison 1000 Transmission Oil Pump is generally reliable, but begins to lose efficiency very early in life and it’s struggle to produce pressure quickly begins to deteriorate as it ages. This will mainly affect the shifting performance of the vehicle.

What signs are shown by this Allison transmission problem?

While driving you will surely notice the shifting difficulty and in worst case complete failure for this problem. As this is a shifting failure, only while driving at the set speed and rpm you will notice this problem.

What is the solution to this Allison transmission problem?

Usually the transmission oil pump is worn out and needs to be replaced to solve this problem. Also in other cases it has been seen that oil pump can be removed and rebuilt to solve this issue. 

Why is poor longevity of bushings a problem with Allison transmissions?

 The Allison 1000’s bushings are made from a weak babbitt material from the OEM. The babbitt material used is notoriously of poor longevity. The bushing failure also can cause shifting difficulty with the transmission.

What signs are shown by this Allison transmission problem?

You will hear noises while driving and will be very unpleasant to your ears which can be taken as a sign that the transmission is having some bushing related problem.

What is the solution to this Allison transmission problem?

Normally this sound means that the bushings with the transmission need to be replaced as it might be fractured. The entire assembly must be removed and rebuilt to fix this problem.

Why is solenoid failure a problem with Allison transmissions?

You would want a seamless and smooth shift even at low throttle input, so if your Allison transmission is harshly shifting from one gear to another even at high throttle then there is definitely a problem.

What signs are shown by this Allison transmission problem?

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.

What is the solution to this Allison transmission problem?

The solenoids of the 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 differential gear failure a problem with Allison transmissions?

A differential gear failure would lead to turning problems especially in the drive. That is why this problem is significant and if not tended would lead to much bigger problems later on.

What signs are shown by this Allison transmission problem?

Usual signs of this problem would be difficulty in driving on the turn. Also, if you plug a diagnostic tool to the transmission control unit, you would get a specific error related to the differential assembly.

What is the solution to this Allison transmission problem?

To fix this problem permanently you would need to replace the gear within the differential so that the same problem will not arise later. 

How to diagnose these common problems with Allison transmission precisely?

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 Allison 1000 fully electronically controlled heavy duty transmission. 

How to prevent getting these problems in the first place?

To prevent these problems you need to change the Allison 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: Allison transmission problems

How do I know if my Allison transmission is going out?

Some of the most common signs are:

  • Slow response time while accelerating
  • Oil Leaks on the bottom side
  • Warning lights on the dashboard
  • Clunking or grinding from the transmission 

How do I reset my Allison Transmission?

To reset your Allison transmission do the following:

  1. Reset the service indicator light.
  2. Turn the key on, do not start the engine.
  3. Move the shift selector to N-D-N-D-N-R-N, pausing briefly (less than 3 seconds) between each selector movement.

Conclusion

In this brief guide, we have provided you with the common Allison transmission problems and what are the solutions to these problems. 

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

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