Brand new 2016 2500HD Allison Extremely hard shifts

[redwngr]

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.

Lots seem to think when they have a problem they should be able to remove the tune, and then gm should pay.

 

My spent 10 or so years running GM diesels and following several forums based around them for about the same amount of time. I'm always amazed how many think GM should pay. (in fairness, they are often/usually new to the tuned duramax world).

Edited October 31, 2016 by redwngr

[BellMob]

My truck has about 200 miles and I also noticed the very hard shifts in the lower gears during hard acceleration. I am hopeful that the transmission and truck are still learning and shifting performance will continue to improve over time.

[Debra in Cali]

So here is an update on my situation. I took it in for the trans issues, and we had them to an oil change. My truck now has 1500 miles on it. So the mechanic dove it and couldn't find the problem. When I came to pick it up I went for a test drive with one of the senior mechanics. It wouldn't do it the first couple of tries, but then it finally showed its true colors. Then on the return trip it did it a second time with me even trying to punch it. The mechanic came back in with me and told my rep that it has a definite problem and that he is going to need to do a reflash on the trans computer. But that he is going to need to call Chevy before doing that. Then he stated that he now has two that have the same issue, so he will take deal with them both at the same time.

 

In the mean time I was told that it is not hurting anything and that I can drive it and even tow the new ginormous trailer. I will bring it back in after I get back from picking up my new 5th wheel.

[pm26]

If I am not mistaken, your owner manual states that WOT driving and hard acceleration should be avoided during the break-in period, which I believe should be around 1000 miles, or so. You should not pull any trailers with a new truck for about 1000 miles to allow the differential gears and bearings to wear in properly without placing extra load on them.

 

That does not mean the transmission should slam hard into 2nd gear when driving aggressively during the break-in period, but if the transmission is actually 'learning" your driving habits, drive conservatively during the break-in period. It is always the best way.

[Debra in Cali]

If I am not mistaken, your owner manual states that WOT driving and hard acceleration should be avoided during the break-in period, which I believe should be around 1000 miles, or so. You should not pull any trailers with a new truck for about 1000 miles to allow the differential gears and bearings to wear in properly without placing extra load on them.

 

That does not mean the transmission should slam hard into 2nd gear when driving aggressively during the break-in period, but if the transmission is actually 'learning" your driving habits, drive conservatively during the break-in period. It is always the best way.

I only do that kind of acceleration when absolutely necessary. I did wait until I had over the 1,000 mile before towing my old trailer. I also did the 50 mph for the first 500 miles of towing. Made me crazy, but we took back roads all the way to and from one of our favorite campgrounds. We now have the new 5th wheel and it tows it beautifully. After we got back with the new trailer, I took it back for the trans reflash. The tech worked on it all day, and even called corporate about another issue that he found. It was all great when I picked it up.

[Nick17]

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?

go to dealer if you havent already there is probably a trans update

[Mightyjoe4]

 I just bought a 2019 3500 HD Duelly and just got to 1212 miles on it. Today I pulled my 38’ toy hauler up to discount tire  to get the tire pressure checked on all the tires and when I left the  tire store I gave it a lot of gas maybe even wide open and Had the exact same thing happened to me, very hard shift from 1st to 2nd gear. It scared the crap out of me and my uncle. We thought that the trailer head popped off the fifth wheel hitch or Something.