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Discussion Starter #1
When your driving in manual setting, do you experience weird shifts?

such as:

- hesitation
- when letting off the gas it has a 1 second engine stall feeling shake (at high rpm)
- when down shifting, the car jerks instead of shifting smoothly, it's a feeling like i pressed the break for a split second)
- 1-2 second lagg between shifting
- the other day i was in sport mode and i gave it a lot of gas, and it was a lagg into lower gear, like it took 2 seconds or 3 seconds to react to me giving it a lot of gas. like it very slowly down shifted.
- to be honest feels like my horsepower isn't constant when i drive the car harder and faster

this isn't all the time, i can make it drive smooth if i drive and accelerate slower. But when i want to accelerate faster the shifting seems very off.

In normal automatic mode, i am also starting to notice sometimes it shifts are off, it pushes the car very soft forward when shifting gears. I can't make it do it in normal automatic mode on demand, but i can do this on demand in manual mode.

i am due for a transmission flush. But i am not sure if it is that.

Does the 2009 G8 3.6 (V6) have a clutch or torque converter? could be that, there does seem to be lagg in the accelerating. I'm not sure.

any advice? When i bring car to shop for transmission flush i want to tell mechanic to check it out, so i will save little money on labor. might need spark plugs, but recently a GM certified dealer said it's not misfiring.

Really not sure what it is
 

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When your driving in manual setting, do you experience weird shifts?

such as:

- hesitation
- when letting off the gas it has a 1 second engine stall feeling shake (at high rpm)
- when down shifting, the car jerks instead of shifting smoothly, it's a feeling like i pressed the break for a split second)
- 1-2 second lagg between shifting
- the other day i was in sport mode and i gave it a lot of gas, and it was a lagg into lower gear, like it took 2 seconds or 3 seconds to react to me giving it a lot of gas. like it very slowly down shifted.
- to be honest feels like my horsepower isn't constant when i drive the car harder and faster

this isn't all the time, i can make it drive smooth if i drive and accelerate slower. But when i want to accelerate faster the shifting seems very off.

In normal automatic mode, i am also starting to notice sometimes it shifts are off, it pushes the car very soft forward when shifting gears. I can't make it do it in normal automatic mode on demand, but i can do this on demand in manual mode.

i am due for a transmission flush. But i am not sure if it is that.

Does the 2009 G8 3.6 (V6) have a clutch or torque converter? could be that, there does seem to be lagg in the accelerating. I'm not sure.

any advice? When i bring car to shop for transmission flush i want to tell mechanic to check it out, so i will save little money on labor. might need spark plugs, but recently a GM certified dealer said it's not misfiring.

Really not sure what it is
Iwas having trouble with mine and then it started to make noise so i took mine in and low and behold the trans had to be rebuilt
And if if its automatic its got a torque converter PM me if you wish and i can give you more details on the problems i was having with my V6.
 

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I know this is in the v6 section so I won't share my experiences with the v8, but I believe this is Torque Management built into your 5-speed to help wear characteristics of the transmission.

This is a similar TSB, but it applies to V8's in the document. I think it can be similar to the V6 as I've driven a V6 as well (considered one as a winter beater one time, lol) and noticed the lag in comparison to my v8 car.

These cars have 100k powertrain warrantees, and although the Bosche ECM of the V6 G8 is a whole different animal as compared to the Delco E38 ECM in the L76 cars, the transmissions of both are factory calibrated to pause upon "thrashy driving" to prevent driveline lash, shock to powertrain components, and overall aid in the handling of the car for those who are not exactly "enthusiasts". That last sentance means no insult, but if your 60 year old mother was driving the G8 v6 and had to perform a crash avoidance maneuver (or possibly floor it to avoid getting hit) then the delays would help to maintain vehicle control and return her to safety as best as possible, with the help of ESC and ABS and TC subsystems.

I am not aware if there are any 5L80e "TCM tunes" like there are for the 6L80e v8 bretheren.

Hope this helps.

--zepcom
 

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I have a few of these symptoms every now and then. It's the torque management doing its thing and yes, I hate it.
 

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Oh by the way up here in Canada the warranty is 5yr/ 160,000 kms at least I just had my tranny rebuilt at 117,000 kms under warranty.
 

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Mine would do some what like yours, as far as down shifting in manual. There will be a hesatation on down shift,My Base i had pretty much did that from the getgo. My biggest problum was the dreaded flair, but mine was from 1-2 instead of 3-4 like most others had.Mine also had a slight hesitation when I floored it with the RPM's a littleblow. She ran best in manual mode with the RPM's above about 2k, it pulled harder as the RPM's were going up.
 

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My biggest problum was the dreaded flair, but mine was from 1-2 instead of 3-4 .
Me too. I find with the right throttle input (not WOT, but close to it) at around 4000 RPM gives a nice drop into 2nd.
 

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+1^ hey King miss the SBM but the white looks good and I'm sure the extra HP has a perma grin on your face...:)
 

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Spot on Rich.:thumbup:eek:
 

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I fixed this on mine by removing torque management and turning up the EPC Solonoid to increase line pressure. But I wouldn't recommend doing either unless you've put 5L50 parts in it as it could cause some breakage of the cheesy 5L40 parts. But at least we know that the operation you describe is normal. GM released the 6L50 in 2007 and had no reason to put 5L40s in this car.
 

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I fixed this on mine by removing torque management and turning up the EPC Solonoid to increase line pressure. But I wouldn't recommend doing either unless you've put 5L50 parts in it as it could cause some breakage of the cheesy 5L40 parts. But at least we know that the operation you describe is normal. GM released the 6L50 in 2007 and had no reason to put 5L40s in this car.
They had to get rid of the 5L40s's on hand I bet..
 
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