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Brand new 2016 2500HD Allison Extremely hard shifts


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Okay, folks please stick with me, this might be a long post, but I want to provide all the information I can so I can get some advice. Last night I signed the paper work on purchasing a brand new Chevy Silverado 2500HD Duramax. To give you a little bit of back ground information, the day started with taking my 2016 1500 5.3 8 speed in for transmission issues. While I was in the dealer I entertained the idea of trading the 1500 in on a 2500HD Duramax. Well, one thing led to another and I decided to trade the 1500 in on a 2500 HD.

 

I am no stranger to diesel pickup trucks or pulling heavy loads with them. I've owned an F250 Super Duty 7.3, F250 6.0 and an F350 6.0. To make a long story short I pulled travel trailers and fifth wheels until we decided to go to a Motor home. BTY, my motor home has a Cummins with an Allison transmission that is flawless. So, back to the brand new 2500HD I just traded up to. While on the test drive, (and I drove this truck for half a day and put approximately 50 miles on it.) I drove it around pretty easy most of the time. This brand new 2500HD did have 200 miles on it.

 

Well, on the way back to the dealer, I decided to go WOT from a dead stop and see what it could do. When I did this the truck slammed into second gear very very very harshly. I mean to tell you the entire truck shook violently and it felt like the rear-end came out of it. In fact, I thought the engine and transmission was going to come out from under it. That is how bad it was. So, when I got back to the dealer I had one of the techs go on a ride with me. We were able to reproduce the condition again. The problem mostly exhibits itself from a dead stop and WOT.

 

We got back to the dealer and they assured me this issue could be resolved with a re-program and it would be good to go. Fast forward a day and the truck has been in the shop all day and mind you I have not took possession of it yet. I talked to the service manager this afternoon and he claims this is normal.

 

Okay, so here I am, I don't know what to think. I know this is not right. I searched all over the net to see if this was a common problem and I really can't come up with anything. I read about harsh downshifts but not this violent 1 - 2 upshift under WOT. So, my question is this, is that normal behavior for these brand new Allisons or should I figure out a way to get out of this to be lemon?

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Over 200 views and no comments. WOW! My suspensions were correct. No comments to this confirmed to me that there was a problem with this truck. Dealer performed software updates and TSB updates on Allison transmission and Duramax. Truck shifts firm but not harsh anymore. This has to be the first time I think in the past 15 years I solely relied on the the manufacturer and the dealer as my 1 source of information for a problem I knew myself they needed to fix. Thanks GM! :D

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  • 2 weeks later...

I just picked up my new 2016 Duramax last Friday. Mine shifted extremely hard when I punched getting on the freeway during a test drive. It almost sounded like a backfire. Well It did it again yesterday when I punched it at a light heading uphill on a passing stretch. This time isn't wasn't as pronounced as the first time.

 

The 2500 is going in for the airbag recall on Wednesday morning. The service tech and I will go for a little test drive when I take it in. This failure is not a option with my 2500. Since I tow I need to be able to punch it if I am climbing a hill with a 5 ton trailer. Also, our driveway in the mountains is on a blind curve. The only way for me to pull out of there is get my nose out there, listen, and then punch it. There has been several times when a car came around the curve just as I pulled out. Definitely an E ticket ride.

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Well, we are just a message board.. the folks who work on the trucks see them day in and day out.. they know more about em then we do.. right? I mean.. umm. When I got my 2008 2500 Dmax (used with 9000 miles on it) I punched it on a test drive as well. It made a sudden jerk and shudder, but that was because the back end broke loose and the G80 diff kicked in. My first time experiencing that on dry pavement since my previous GM trucks could never break traction on dry pavement.

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The combination of a transmission reprogram, relearning, disabling ABS (when I feel like WOT starts) solved the issue. I've talked to a few other Duramax owners and they all said that the Allison will shift very hard first to second under WOT. I've had no other issues since day 1.

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  • 3 weeks later...

The combination of a transmission reprogram, relearning, disabling ABS (when I feel like WOT starts) solved the issue. I've talked to a few other Duramax owners and they all said that the Allison will shift very hard first to second under WOT. I've had no other issues since day 1.

It's the torque management system. Mine had hard 1st and 2nd shifts too. Mine also makes a clunk/loud shift going into 4th
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Well, on the way back to the dealer, I decided to go WOT from a dead stop and see what it could do. When I did this the truck slammed into second gear very very very harshly. I mean to tell you the entire truck shook violently and it felt like the rear-end came out of it. In fact, I thought the engine and transmission was going to come out from under it. That is how bad it was. So, when I got back to the dealer I had one of the techs go on a ride with me. We were able to reproduce the condition again. The problem mostly exhibits itself from a dead stop and WOT.

 

We got back to the dealer and they assured me this issue could be resolved with a re-program and it would be good to go. Fast forward a day and the truck has been in the shop all day and mind you I have not took possession of it yet. I talked to the service manager this afternoon and he claims this is normal.

 

Okay, so here I am, I don't know what to think. I know this is not right. I searched all over the net to see if this was a common problem and I really can't come up with anything. I read about harsh downshifts but not this violent 1 - 2 upshift under WOT. So, my question is this, is that normal behavior for these brand new Allisons or should I figure out a way to get out of this to be lemon?

I am not 100 % sure what WOT stands for, but I am assuming that you are giving it full throttle and seeing what it can do from a full stop. I did the same thing and had the same result. I backed off and stated, "That didn't sound good". The salesman agreed with me that it didn't sound good. I asked him if that was normal and he said NO.

 

So I headed up the hill to our property about 2 weeks ago. I was at one of the stoplights and had a bunch of slow pokes in the high speed lane. The road was going back down to one lane, so I punched it to get in front them, same result. So my husband took my truck in for the airbag recall since I was sick that day. I asked him to have them look at it with the sound it was making when you punched it. He did not even mention it to them. He told me that it was a fluke and that it was fine. GRRRR. Never let a man do a women's job.

 

It did it again a few days ago, getting on to the freeway. So I will be taking it in for them to fix it. I agree it sounds terrible when it does it. I thought that it backfired. But it causes the truck to lurch when it is happening. I need to be able to punch it when I am pulling a trailer and heading up a steep hill. We have several places, like pulling out of our mountain property place onto a highway, with high speeds and lots of traffic where we need to be able to punch it and not worry that the transmission is going to be left in the roadway.

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I've put about 1500 miles on the truck so far. After the first transmission reset to relearn, I am the only one who has drove my truck. I have performed a mix of easy accelerations, and really mostly easy accelerations and some very hard accelerations. I have only done a WOT maybe twice, yes twice. The Allison, for the most part shifts like butter now. Under hard acceleration, the shifts become very firm, which is to be expected with the Allison 1000. Under the few WOT accelerations I have performed, the transmission still shifted from 1 to 2 very hard, but now like the first time before purchase and re-learn.

 

I have done quite a bit of research on the Allison transmissions. The way the clutches clamp down and hold the carrier gears and the how the planetary gears transfer power to the output shaft from the input shaft just amazes me. The Allison will constantly monitor shifts to make them better each time. Good stuff.

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Do you have to reset with a tech 2 or is there a way to initiate it outside of a dealer/programmer?

 

 

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Good question. I have no Idea. One day, when I get a programmer, I'd hope it has that functionality. I have not had the chance to research it. Maybe someone will chime in. It kinda bums me out the 2017 has a 90% redesigned Duramax with 445HP and 910Ff lbs of torque. But that shouldn't be anything a programmer couldn't fix for me on my 2016. :D

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Good question. I have no Idea. One day, when I get a programmer, I'd hope it has that functionality. I have not had the chance to research it. Maybe someone will chime in. It kinda bums me out the 2017 has a 90% redesigned Duramax with 445HP and 910Ff lbs of torque. But that shouldn't be anything a programmer couldn't fix for me on my 2016. :D

Just be glad your not a guinea pig on the new engine. I did that once, never again... I bought the LML because it's a proven engine and is more than capable of pulling just about anything. I can care less about the gains on the new engine. Hope your tranny issues get resolved quickly
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In models in the past you could kind of reset things by unhooking the battery cables for about 30 min, touch the cables together to discharge any additional power in the system, then re-connect. That would put things back into learning mode. Just make sure you pull off BOTH sets of cables first if you have dual batteries!

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  • 2 weeks later...

Good question. I have no Idea. One day, when I get a programmer, I'd hope it has that functionality. I have not had the chance to research it. Maybe someone will chime in. It kinda bums me out the 2017 has a 90% redesigned Duramax with 445HP and 910Ff lbs of torque. But that shouldn't be anything a programmer couldn't fix for me on my 2016. :D

Except the 17 will have a warranty at the near 20% higher torque level.

 

The program/tuner supplier likely won't warranty the drivetrain they help you revise... :(

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Except the 17 will have a warranty at the near 20% higher torque level.

 

The program/tuner supplier likely won't warranty the drivetrain they help you revise... :(

Does that really need to be stated? Do you honestly think those who purchase a programmer expect GM to fix their blown head gaskets and blown turbos and screwed up Catalysts DEF systems when they soup one up? Really? Come on.

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