[cmitchell17]

I would like to see the tune file for a 2019, I'm curious if they did throttle map changes or changes to the torque based control to improve driveability. My 17 SS with an 8L90 has horrendous drivability. Especially in low gears, if you are in stop and go traffic you have to extremely carefully apply the throttle and very slowly let off, if not you will get jerked back into the seat and when you let off get jerked forward. Along with a huge clunk and bang from the driveline slop and movement up and down. Its really embarrassing when you have a passenger and they thing your car is broken because its so jerky and violent with so much clunk and slop. I really want to drive a 2019 to see if they attempted to address any of this. I take it they probably didn't since GM thinks no one cares about this kind of stuff and they only care about stupid stuff like wind noise and completely ignore major drivability and refinement problems.

[weatherman71]

Originally Posted by Elvis66

So I just got the A10 transmission in my new SS ..I also have 19 mustang GT with the A10 ...they do not feel the same at all ..the A10 is more jerky in low gears in the mustang and the Camaro seems more smoother . Just my first impressions so far.

you are correct... i had a 18 gt with the A10 and the camaro one is years better.

[arpad_m]

Originally Posted by cmitchell17

I would like to see the tune file for a 2019, I'm curious if they did throttle map changes or changes to the torque based control to improve driveability. My 17 SS with an 8L90 has horrendous drivability. Especially in low gears, if you are in stop and go traffic you have to extremely carefully apply the throttle and very slowly let off, if not you will get jerked back into the seat and when you let off get jerked forward. Along with a huge clunk and bang from the driveline slop and movement up and down. Its really embarrassing when you have a passenger and they thing your car is broken because its so jerky and violent with so much clunk and slop. I really want to drive a 2019 to see if they attempted to address any of this. I take it they probably didn't since GM thinks no one cares about this kind of stuff and they only care about stupid stuff like wind noise and completely ignore major drivability and refinement problems.

This is absolutely not normal, my 8L90 works like a dream with a tune and wasn't bad to begin with. Do you already have a TCM tune, or only ECM?

[18LTLoveIt]

No problems with shudder yet on my 8 speed, low miles. 3300. No doubt A10 is smoother but I couldn't trade in my V6 Hyper Blue RS. Riverside blue is okay on the 2019/2020's



I don't need a V8 2020 or want a LT model. I don't like the sloping grill with flat black plastic by the headlights on the LTs. I'm mad for the Rally Green color though. The thought of getting a SS just to get a better face front is too much, price & HP. So I'll keep the 2018 indefinitely.

[cmitchell17]

Originally Posted by arpad_m

This is absolutely not normal, my 8L90 works like a dream with a tune and wasn't bad to begin with. Do you already have a TCM tune, or only ECM?

I have both ECM and TCM, there's not much you can do with the TCM besides disable TCC lockup at zero throttle this let's the torque converter absorb the sloppy coasting downshifts disabling TCC lockup dosent help much with the upshift quality and I would rather have it locked.

I would bet that a lot of the poor driveability is due to the drivetrain slack/slop and the movement in the driveshaft carrier bearing/support.

The 8L90 can shift good in some situations but it's biggest problem is it's inconsistentcy. I think my car is probably normal but I'm much more OCD and demanding than the average customer.

[Joshinator99]

Originally Posted by arpad_m

This is absolutely not normal, my 8L90 works like a dream with a tune and wasn't bad to begin with. Do you already have a TCM tune, or only ECM?

Agree 100%. My A8 has been flawless.

[KMPrenger]

Originally Posted by arpad_m

This is absolutely not normal, my 8L90 works like a dream with a tune and wasn't bad to begin with. Do you already have a TCM tune, or only ECM?

Yep, same here. While the A8 does have wide spread TC issues, my 8 drives pretty well. I only get a little jerk when it's initially cold, but after that first shift it's fine. What hes describing is in no way the normal function of the A8.

[HCGxKaLiBeR]

A8 jerk yes. However after the 3rd (newest fluid) flush, it smoothed out alot. Also no more shudder issue since.

[arpad_m]

Originally Posted by cmitchell17

I have both ECM and TCM, there's not much you can do with the TCM besides disable TCC lockup at zero throttle this let's the torque converter absorb the sloppy coasting downshifts disabling TCC lockup dosent help much with the upshift quality and I would rather have it locked.

I would bet that a lot of the poor driveability is due to the drivetrain slack/slop and the movement in the driveshaft carrier bearing/support.

The 8L90 can shift good in some situations but it's biggest problem is it's inconsistentcy. I think my car is probably normal but I'm much more OCD and demanding than the average customer.

You are probably much more sensitive to drivetrain inconsistencies than the majority of us, but I swear there are no obvious issues with my A8 and you probably have a hardware or a tune problem with your specific unit.

To rule out any potential "rose tinted glasses" perspective on my part, I asked around and no adult who ever rode shotgun with me (not too many people in total, heh) observed any trans issues either, be it WOT or part throttle upshifts, 3-1 downshifts on entering an incline, downshifts during decel, coasting, manual up/downshifts etc. The trans has near perfect consistency in basically any scenario.

Using the paddles is somewhat anticlimactic due to the suboptimal response time, but that is really all there is to the "problems" bin.

I do make sure I engage the parking brake in N, then release the brake for a moment before shifting to P when parking the car. Can also check anything in the tune for you if interested.

[MakCamaro]

My A8 is 100% flawless.

[cmitchell17]

Originally Posted by arpad_m

You are probably much more sensitive to drivetrain inconsistencies than the majority of us, but I swear there are no obvious issues with my A8 and you probably have a hardware or a tune problem with your specific unit.

To rule out any potential "rose tinted glasses" perspective on my part, I asked around and no adult who ever rode shotgun with me (not too many people in total, heh) observed any trans issues either, be it WOT or part throttle upshifts, 3-1 downshifts on entering an incline, downshifts during decel, coasting, manual up/downshifts etc. The trans has near perfect consistency in basically any scenario.

Using the paddles is somewhat anticlimactic due to the suboptimal response time, but that is really all there is to the "problems" bin.

I do make sure I engage the parking brake in N, then release the brake for a moment before shifting to P when parking the car. Can also check anything in the tune for you if interested.

What specifically have you found in the tune to make the 8L90 shift better?
I've been messing with shift times, but since we don't have the correct PIDs to monitor the actual shift times its kind of just adjusting blind. I feel like I may have somewhat fixed the inconsistent (vs other shifts) 3-4 shift that is unnecessarily hard. You can see in the tune file the 3-4 shift times are faster than the other shifts. I still firmly believe if we could stabilize the driveshaft better (or get an aftermarket one piece driveshaft which is expensive) it would help a lot and get rid of the horrible random clunking and clanging and noise you hear when coasting and downshifting and letting off the gas and on the gas. I drove a CTS 2.0T rental and while the same driveshaft movement/clunk/slop was present it didn't feel nearly as bad as my SS.

[DrkPhx]

I would get the a10 and never look back. I rented a 2019 SS with the a10 and a v6 with the a8. Big difference in overall feel. The a10 doesn't hunt like the a8 driving around town and wot shifting is awesome. The blind spot detection on the aide mirrors is nice as well.

[Yanniz]

My 2017 w/A8 and 35K miles, built on May 2017 (I thought they had the new fluid by then) is going to the dealer today for shudder issues.

Just all of a sudden started acting up on the freeway on July 5th. Sucks.

[arpad_m]

Originally Posted by Yanniz

My 2017 w/A8 and 35K miles, built on May 2017 (I thought they had the new fluid by then) is going to the dealer today for shudder issues.

Just all of a sudden started acting up on the freeway on July 5th. Sucks.

There is an even newer fluid as of Jan 2019, plus some specialized additional equipment to perform "more thorough" flushes. Your dealer hopefully used the new fluid.