[Silverwing]

I've been doing a lot of reading on the shudder and possible fixes, I've seen a lot of posts claiming that tunning the transmission to remove the slip that it's programmed to do will fix the dreaded shudder, and that makes sense.

My question is, has anyone who had the shudder got a tune on the TCM and is completely free of the shudder?
I'm looking for actual people who did this and got any sort of result whether it went away or didn't.

I'm looking to tune my TCM to get rid of the shudder but only want to lose my warranty if it actually works and is permanent.
Thanks guys.

[mlee]

You can get a brand new TC with your current warranty.

Not sure why you would want to take the chance by tuning. Even if someone does come in here and say it's a fix, then why wouldn't GM just flash the tune for a fix.

[parish8]

Originally Posted by mlee

You can get a brand new TC with your current warranty.

Not sure why you would want to take the chance by tuning. Even if someone does come in here and say it's a fix, then why wouldn't GM just flash the tune for a fix.

For those of us tuning for mods already it might make sense. My car developed the shudder after I had done a few minor mods. I choose to just fix it myself rather than risk getting flagged as modified. I would have loved to have had a tuning solution back then.

[Silverwing]

Originally Posted by mlee

You can get a brand new TC with your current warranty.

Not sure why you would want to take the chance by tuning. Even if someone does come in here and say it's a fix, then why wouldn't GM just flash the tune for a fix.

From my understanding, even with a new TC the problem will come back. As the issue isn't the TC as much as it is the programming of slip in 7-8 gear.

Did I get that wrong?

Also I've been using a range device to keep my car out of v4 mode, in an effort to reduce as much wear on the transmission/TC as possible. It definitely helped but it still happens, albeit less often.

[KingLT1]

Originally Posted by mlee

You can get a brand new TC with your current warranty.

Not sure why you would want to take the chance by tuning. Even if someone does come in here and say it's a fix, then why wouldn't GM just flash the tune for a fix.

A brand new torque converter doesn't fix the issue. GM is no longer replacing torque converters. The new fix is supposedly to be released on Q1 2019. For now they are just continuing the band-aid fluid flush.

My guess is if the EPA found out the GM was reprogramming these SS A8 cars so AFM and the slip tables were disabled, there might be some hefty fines because this reduces fuel mileage a bit by 1-2mpg.

[parish8]

the tuning fix I am aware of just reduces tcc slip to 0. it has nothing to do with 4cyl mode and shouldn't effect mpg.

[KingLT1]

I know what the tuning fix is...I did mine a while ago. You are correct setting the slip tables to 0 doesn't effect mpg, but turning off AFM does. AFM should also be turned off from what I was told that is why I tied it in with my last post. Anyhow, my tcm is tuned, afm is off and I have no converter shudder.

[mlee]

Originally Posted by parish8

For those of us tuning for mods already it might make sense. My car developed the shudder after I had done a few minor mods. I choose to just fix it myself rather than risk getting flagged as modified. I would have loved to have had a tuning solution back then.

Different situation than the OP described and I would do the same as you.

Originally Posted by Silverwing

From my understanding, even with a new TC the problem will come back. As the issue isn't the TC as much as it is the programming of slip in 7-8 gear.

Did I get that wrong?

Also I've been using a range device to keep my car out of v4 mode, in an effort to reduce as much wear on the transmission/TC as possible. It definitely helped but it still happens, albeit less often.

Of the ones I've seen get replaced personally I haven't heard of any further issues but will check back in on this subject since I sort of stopped paying attention after Al gave his response. KingLT1 seems to be on top of it right now, but if you are worried about warranty then be careful with tuning. Turning off AFM is as simple as flipping a switch but it constitutes a tune flash.

Originally Posted by KingLT1

A brand new torque converter doesn't fix the issue. GM is no longer replacing torque converters. The new fix is supposedly to be released on Q1 2019. For now they are just continuing the band-aid fluid flush.

Thanks for the info and not discounting anything you've said but is there any bulletin or something that has this in writing? I see I need to do some digging around to get current on this one.

[KingLT1]

https://www.camaro6.com/forums/showthread.php?t=540478

https://www.camaro6.com/forums/showp...3&postcount=92

https://www.camaro6.com/forums/showp...&postcount=154

[TJay74]

Originally Posted by parish8

the tuning fix I am aware of just reduces tcc slip to 0. it has nothing to do with 4cyl mode and shouldn't effect mpg.

Hey Parish what all slip tables are you all turning off in the TCM via HPT? I just had the flush done on my 2016 Sierra 6.2/A8. I have tuned the truck but havent messed with the TCC slip tables yet.

Used to be we found if the tables were zero'd out we got a slight increase in gas mileage but at the cost of feeling the converter lock up.

That is the only reason I see GM allows the slip now, it is like they dont want you to feel any of the shifts or the converter locking up at all.

[parish8]

Originally Posted by TJay74

Hey Parish what all slip tables are you all turning off in the TCM via HPT? I just had the flush done on my 2016 Sierra 6.2/A8. I have tuned the truck but havent messed with the TCC slip tables yet.

Used to be we found if the tables were zero'd out we got a slight increase in gas mileage but at the cost of feeling the converter lock up.

That is the only reason I see GM allows the slip now, it is like they dont want you to feel any of the shifts or the converter locking up at all.

I never tried fixing the tcc issue with tuning. we didn't have access to those tables when I had a converter issue. now I have an aftermarket tq converter and ended up zeroing out all the slip tables. it has a noticeable engagement, like another gear. I had a hard time getting tuning that I was happy with and ended up just shutting off the lock up until light throttle above 50mph.

[KingLT1]

Originally Posted by TJay74

Hey Parish what all slip tables are you all turning off in the TCM via HPT? I just had the flush done on my 2016 Sierra 6.2/A8. I have tuned the truck but havent messed with the TCC slip tables yet.

Used to be we found if the tables were zero'd out we got a slight increase in gas mileage but at the cost of feeling the converter lock up.

That is the only reason I see GM allows the slip now, it is like they dont want you to feel any of the shifts or the converter locking up at all.

TCC Desired Slip under the Torque Converter tab. From what I have experienced it has nothing to do with the feel of shifts or the converter locking up. I can feel both just fine with TCC slip tables Zero'd out.

Originally Posted by parish8

I never tried fixing the tcc issue with tuning. we didn't have access to those tables when I had a converter issue. now I have an aftermarket tq converter and ended up zeroing out all the slip tables. it has a noticeable engagement, like another gear. I had a hard time getting tuning that I was happy with and ended up just shutting off the lock up until light throttle above 50mph.

I too have part throttle lock up disabled until 8th gear 55 mph. Cost some MPG, but the A8 is much nicer to drive this way. I also have noticed that it helps to reset the the TCM under VCM controls any time you make a significant change to the TCM tuning and let it relearn.

[mlee]

Originally Posted by KingLT1

...

[TJay74]

Originally Posted by KingLT1

TCC Desired Slip under the Torque Converter tab. From what I have experienced it has nothing to do with the feel of shifts or the converter locking up. I can feel both just fine with TCC slip tables Zero'd out.



I too have part throttle lock up disabled until 8th gear 55 mph. Cost some MPG, but the A8 is much nicer to drive this way. I also have noticed that it helps to reset the the TCM under VCM controls any time you make a significant change to the TCM tuning and let it relearn.

Thanks King, I am going to play with this tables later this week on my truck then. Have either of you played around with the pressure offset tables and in increasing the pressure? I saw that we just got access to those tables with the most recent HPT update.