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Allison transmission won't shift - Cars & Trucks

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SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

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Posted on Jan 02, 2017

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SOURCE: My 2001 GMC duramax with

Thanks for choosing FixYa and welcome to the site. The first thing you need to do is check your transmission fluid. Make sure it is at the correct level. You may need to change the fluid and change the filter. If you haven't did this, I would advise you to do it. You would be surprised to see the difference, if that is the cause. It is very hard to diagnose a transmission problem because there is no way to find out other then taking it apart. It could be damged teeth, seal, ect. It is possible that you have a bad torque converter. But the only way to know for sure is looking at it or having a mechanic look at it. Now, the transmission should throw a fault code. If your check engine light is on, this may be the reason why. If so, you need to take it to Autozone or Advanced and have the codes read. It may tell what is wrong. If there is no check engine light, it is possible that you may just need a fluid change. I would change the filter and fluid first. Transmission maintenance can be very expensive. Shifting can become hard if there is low fluid or you need a new filter. Pay attention to the housing and see if it is leaking any fluid. This could be a sign of a bad seal. The transmission also has sensors that can fail. If the fluid change doesn't help, your only option is taking it off yourself or haing a mechanic do it for you. This is just one of those things that you need a hands on experience to know the exact cause of your problem.

Posted on Jul 25, 2011


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Stops shifting after i start driving

Allison transmissions are fairly reliable. don't really burn up unless you run them dry to many times. First you need to have the codes read. Even some engine codes will make transmission not run right. Then I would be checking the wires to the transmission for the ECM/TCM (Ohm test them). Along with the plugs for corrosion.

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Transmission solenoids are usually installed in a transmission valve body, Transmission Control Unit, or transmission control module. If you have a question about a specific Allison Transmission model, you should call Allison Transmission Here is the number for the Texas Distribution office 214-631-5370-----------------------------------------------------------------------------
vas 5054a

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Shift solenoids on the valve body inside the transmission or the transmission control module will cause that if it's electrical. Clutch packs if it turns out to be mechanical.

Sep 23, 2012 | Cars & Trucks

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Will a transmission from 2003 duramax fit in a 2004 duramax?

They will deefinitely providing the 2 are the same model. In 2004 the Allison tranny was available in a 5 or a 6 speed. Before 2004 only the 5 speed was used. If one is changed for the other there will be shifting issues and codes set in both the ECM (engine control computer) and TCM (transmission control computer). Make sure you are putting in a 5 speed Allison tranny.

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No, have you changed the spin-on filter om the transmission yet? This may be the only trouble. I hope this helps. Good luck.

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Having a problem with my allison md 3060 transmission

Hi mate I had the same problem with a camper once and the only way that you will ever stop it from shifting hard into gears down shifting or up is to take it into a Detroit Allison work shop and ask them to reset the throttle position and reset Un-adaptive shifts then to do an Fast-adaptive shift with the electronic tool called Allison Doc.

Ask them also to do a clutch report on the electronic tool, that will tell you straight away the condition of the box on the inside.

Thats the problem with these new electronic transmissions they force you to go back to the suppliers. If I had my book here I could have helped you with the fault code but you would have had to take it in any way to get all the parameters reset.

What happens is that when you buy this trans new they set it to UN-adaptive shifts then to fast adaptive then it learns how long the solinoids should be open and how quick to open them to have a good shift, but over a few ignition cycles the fast-adaptive changes to normal over a year or two the clutch plates wears with a few 001 and the computer cant keep up have to be reseted which is normal to them, expect to take it back every year or two to be reseted.

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