[money_man]

Last week when I drove 4 hours away and I was coming off the highway I noticed a firm downshift. It was firm enough that my passenger who knows nothing about cars asked if something just broke. I've experienced it probably 3 more times since but that was mostly on the way home after about 2 hours of driving.

Is this normal? Haven't noticed it since and never noticed it before but I've never done a drive that long.

2014 cruze diesel
48k km
All maintenance up to date.

 

[pandrad61]

mine after it warms up will down shift a tiny bit rough untill very hot. have you flushed the trans yet?

 

[money_man]

No I haven't. Actually email a local amsoil distributor to see how much for a case of signature series atf.

 

[pandrad61]

im not sure ok Km to miles conversion but sever manual recommends 45k miles. im at 17 and i may just do it at 25k... i drive mine quite hard

 

[money_man]

I drive mine easy but it's almost 100% city

 

[pandrad61]

Same here 90% city and its very very hot here in florida. At least once a day i do a wide open throttle pull

 

[pandrad61]

Gm should have done a better job with trans shift software. It still fells like it was taken for a gasser and hap haphazardly tuned for a diesel. Especially first 2nd and 2nd converter lock up. The down shifts are horribly slow and i hate that shift denied bs

 

[money_man]

Shift denied makes me furious so I don't use manual shifting at all. Trifecta tune is supposed to smooth out the shifting but it's currently like $750 with Exchange rates to Canada.

 

[pandrad61]

shift denied makes me furious so i don't use manual shifting at all. Trifecta tune is supposed to smooth out the shifting but it's currently like $750 with exchange rates to canada.

just go with fleece 100% emmisions delete ( for off road vehicles only) and fix that while problem

 

[money_man]

Still have 2.5 years of power train left and 4.5 years of extended warranty.

 

[Snipesy]

No one can actaully tune the TCM except for Aisin itself.... Shame really, there's nothing inherently bad about the transmission itself.

 

[jblackburn]

Don't worry, the gas programming is terrible too. One of the worst I've ever driven.

They seem to have done a much better job with the transmission in 2nd gen/2016 Cruze.

 

[money_man]

The af40 is actually described as a smooth shifting transmission on other vehicles. Wonder why ours is so firm.

 

[jblackburn]

The af40 is actually described as a smooth shifting transmission on other vehicles. Wonder why ours is so firm.

So is the 6T40 on other GM vehicles, but it is terrible in the Cruze. I've got to wonder if they favor lock-up scenarios with the programming as much as possible and "quick" changes rather than slurring shifts with the torque converter on these cars for max. fuel economy.

 

[money_man]

Not sure. Would love to smooth out that harsh downshift.

 

[CruzeDan]

So is the 6T40 on other GM vehicles, but it is terrible in the Cruze. I've got to wonder if they favor lock-up scenarios with the programming as much as possible and "quick" changes rather than slurring shifts with the torque converter on these cars for max. fuel economy.

BINGO. Its all about the MPGs. The way these cars shift they are in lockup much more than cars in the past, and other vehicles in the lineup, for maximum power transfer without loss. I don't find my 6 speed in the diesel offensive, but I wouldn't call it smooth. And it isn't any better than the gassers, they have their own quirks as well.

 

[money_man]

I don't mine city driving my diesel but I do find coming to a stop after a long drive to have a weird firm downshift, not sure which shift it is though.

 

[DslGate]

No one can actaully tune the TCM except for Aisin itself.... Shame really, there's nothing inherently bad about the transmission itself.

Weve tuned MB AMG cars transmissions very successfully. There's several tuners who do both ECM and trans as a package with much success. Eurocharged is one such tuner.

 

[spacedout]

I know its not he same transmission, but with my 2012 1LT gas cruze the 5th to 4th downshift at 28mph was strange. If you were completely off the gas the shift was drawn out, slowing the car from compression braking considerably while it shifted. On the gas very lightly but loosing speed though the shift point was abrupt but not harsh at all. Now if you were on the gas anything more than lightly and you slowed through that speed it would clunk harshly into the lower gear. The 5th/6th shift at 40mph would also sometimes behave the same, I just learned to use very light throttle inputs when driving near those speeds.

Only car I've ever owned where my throttle inputs seemed to have any effect on the shift quality. Interestingly the same exact transmission in my 2015 sonic doesn't seem to have this issue or its much less pronounced.

 

[money_man]

Kind of curious if there's any transmission software updates yet for the diesel