[DarkFangz1100]

All,

If you have the A8 I4...if it starts stuttering take it to the dealer and/or have it towed....Just destroyed my transmission from driving it a few miles with a stutter. Hopefully will be covered under warranty hoping they can get me pictures of the damage too! Will post if I do.

[Evil-Bee-NH]

Torque Converter.... did the whole transmission burst to pieces or just stop working?

[HCI2000SS]

Wow I'm surprised it destroyed the trans so quickly like that.

[DarkFangz1100]

Originally Posted by Evil-Bee-NH

Torque Converter.... did the whole transmission burst to pieces or just stop working?

The car doesn't budge....input shaft spins and holds RPMs ...output shaft gets about 500 rpms at most but 90% of the time sits at 0

Doesn't register Reverse on HPT
RPMs spike and hold when you try to throttle in any gear

Originally Posted by HCI2000SS

Wow I'm surprised it destroyed the trans so quickly like that.

As am I figured I'd be okay for a few miles of LIGHT driving but guess not lol

[Evil-Bee-NH]

Originally Posted by DarkFangz1100

The car doesn't budge....input shaft spins and holds RPMs ...output shaft gets about 500 rpms at most but 90% of the time sits at 0

Doesn't register Reverse on HPT
RPMs spike and hold when you try to throttle in any gear



As am I figured I'd be okay for a few miles of LIGHT driving but guess not lol

Damn. Sorry this shit happened to you. I hope GM warranties everything the 8speed issues are finally getting more publicity.

[dekes1]

Originally Posted by DarkFangz1100

All,

If you have the A8 I4...if it starts stuttering take it to the dealer and/or have it towed....Just destroyed my transmission from driving it a few miles with a stutter. Hopefully will be covered under warranty hoping they can get me pictures of the damage too! Will post if I do.

The stuttering issue that affected the 8L90 was related to the lockup of the TCC and although it could cause damage to the clutches, there's no way it could cause the trans to destrroy itself and lock up solid. I'm very curious what the root cause is in this case since it sounds like something very different than what affected the 8L45's bigger brother.

Edit: you mention HPT so I assume your trans was tuned; were you running over 862kpa main pressure? Any changes to the desired slip tables?

[cooper1965]

Originally Posted by dekes1

The stuttering issue that affected the 8L90 was related to the lockup of the TCC and although it could cause damage to the clutches, there's no way it could cause the trans to destrroy itself and lock up solid. I'm very curious what the root cause is in this case since it sounds like something very different than what affected the 8L45's bigger brother.

Edit: you mention HPT so I assume your trans was tuned; were you running over 862kpa main pressure? Any changes to the desired slip tables?

862kpa would only be about 125 PSI. They are 115psi in stock form. 125PSI would barely give any room for shift speed increases, much less other things. Most guys are staying around 145-150psi on full tunes with no issues when done correctly. I have seen much higher than that even, but time will tell on those.

[dekes1]

Originally Posted by cooper1965

862kpa would only be about 125 PSI. They are 115psi in stock form. 125PSI would barely give any room for shift speed increases, much less other things. Most guys are staying around 145-150psi on full tunes with no issues when done correctly. I have seen much higher than that even, but time will tell on those.

Agreed: but with the caveat that you're not adding in additional pressure via any of the modifiers.
But in the end, that's what I was hinting at by asking the question on whether his tune was running more than 125psi or not. It would help those of us running higher base pressure to see if there is a reliability concern.

[DarkFangz1100]

Originally Posted by dekes1

Agreed: but with the caveat that you're not adding in additional pressure via any of the modifiers.
But in the end, that's what I was hinting at by asking the question on whether his tune was running more than 125psi or not. It would help those of us running higher base pressure to see if there is a reliability concern.

I'm running 129 psi in the last tune I had at the time of the incident I was doing 37 MPH I don't think pressure wise it's an issue.

In my personal opinion(I'm not 100% on these transmissions) with the TCC Locking up it causes the output shaft to lockup and just shred the teeth on it in a violent stutter. So if the car isn't getting any power to the rear wheels with my limited knowledge I'd connect my destruction to the TC locking at times.

Which the person doing my tune is apart of Camaro6 if he can shine any more light on it he can only if he wants to make it public.

[Evil-Bee-NH]

Did you adjust slip% tables when you tuned your TCM? I'm not certain what my pressure is I'd need to look but i know it's high af according to cooper. I've been driving with the TCM adjustments since last spring so if it was gonna fail I'd think it would have by now or show signs of any issues

[DarkFangz1100]

Originally Posted by Evil-Bee-NH

Did you adjust slip% tables when you tuned your TCM? I'm not certain what my pressure is I'd need to look but i know it's high af according to cooper. I've been driving with the TCM adjustments since last spring so if it was gonna fail I'd think it would have by now or show signs of any issues

Everything was adjusted to my best knowledge. However, if yours is a lot higher than mine and I'm sure Allen's car is also ALOT higher than mine... I'd rule that out as a factor.

[Austin_504]

Hey guys, I just recently started getting the shudder. It’s mostly on the interstate when giving around 10% throttle. What course of action should I take with this? Call my local dealer and schedule an appointment?

[Evil-Bee-NH]

Originally Posted by Austin_504

Hey guys, I just recently started getting the shudder. It’s mostly on the interstate when giving around 10% throttle. What course of action should I take with this? Call my local dealer and schedule an appointment?

Can't hurt. Sounds like low line pressure.

[Austin_504]

Originally Posted by Evil-Bee-NH

Can't hurt. Sounds like low line pressure.

Thanks, I’ve been driving exclusively in manual mode ever since I got my cat back, but last week I noticed it when I drove in auto. Is there a fix yet or is it still that triple-flush “band-aid” fix?