[Spaceme1117]

Originally Posted by Fiyero88

My 2018 Camaro has 40,000 miles on it. In the morning when the engines cold. It will literally almost throw me out of my seat leaving the driveway when it shifts between 1st and second. The dealer said that's normal, I said I've never driven a car that does that. They also did nothing because they said the tech couldn't recreate it. Well no duh they didn't let it sit overnight ��so they wouldn't be able to recreate it.

Not sure if it would apply to your car since it is a 2018, but there is a TSB for 2017 cars with the A8 to do a software update.

I know this because my 2017 has always had a harsh 1 to 2 shift every now and then. And my car threw a CEL, P0797. It also shifted from 1st to 2nd and would not shift until I pulled over, turned the car off and then back on.

TSB describes everything my car has been doing. I have an appointment on Tuesday of next week at a stealership. Going to print out the TSB and hope they don’t dick around and waste my time. I think I am out of warranty so hopefully I’ll only have to pay for the time it takes to do the software update.

[Spaceme1117]

Originally Posted by Fiyero88

Just left the dealership. They said it's completely normal and the masterechanic came out and said" Chevy designed the A8 poorly, they didn't put a release valve on the A8 so the hydraulic fluid builds up in the mornings and eventually releases causing the car to lunge forward or hard shift. I asked him if it would bother anything and he said Chevy says no it won't ruin the engine. Then he said they designed the A10 to eliminate that problem. But the guy said he's already had headaches with customers complaining about the A10 and he said the A10 will have loads of problems down the line. So basically he's saying that these torque converters are trash. I actually trust him because he works on them all day and really explained to me why the A8 is no good.

So doing a bit of searching, I cam across a TSB that includes 2018 Camaros with the 8L90.

It is 16-NA-361. "Information on Transmission Harsh 1-2 Shift Upon First Start Up/Shift of the Day Under Light Throttle".

Unfortunately, it says exactly what they told you and specifically says to do nothing.

I have attached the TSB.

My 2017 fits the symptoms of the 16-NA-404 TSB.

[KingLT1]

A lot of the A8's quirks are in the tuning. Properly tuned it's right up there with a A10 other then the paddle shift response time isn't as fast. GM did a better job with the tuning on the A10.

One thing I would do is reset the shift adapts on the A8 and let it relearn. Especially if you bought the car used and/or had the fluids and/or converter changed. Dealership can do it by request...so can HPtuners if you have it or know somebody that does.

[arpad_m]

I come here to answer and lo, the King of the LT1 has already weighed in, so I'll just add one data point: I have the same "trash" 8L90 with the latest 2019 fluid, and it's perfect, no clunks or lurches or shudder. Yes, it is tuned.

[len_eng]

I started having a problem with the shudder at 58,000 miles on my 2018 2SS A8. I asked the dealer to do the fluid flush and they told me they could not duplicate the issue. Took it for a test drive at 63,000 miles and they told me I had to pay for the flush ($300+ at the time), they would not cover it under the extended warranty. It did resolve the problem, however it should have been done under warranty and I should not have had to pay for it. When I purchased my 2021, I found another dealer with a better ratings even though I had to drive a ways. So far they have really been awesome.

[Fiyero88]

Not the king of anything and also didn't weigh in on anything just telling you what the master mechanic said �� your crummy attitude is what makes this forum kinda crummy tbh. Also why weigh in on a recall post if there's nothing wrong with yours?

Originally Posted by arpad_m

I come here to
answer and lo, the King of the LT1 has already weighed in, so I'll just add one data point: I have the same "trash" 8L90 with the latest 2019 fluid, and it's perfect, no clunks or lurches or shudder. Yes, it is tuned.

[Fiyero88]

How do I do that? Would it void the warranty? They didn't offer to do anything because like he said that's just what they do. I don't know anymore than what he's saying and I'd assume he works on them all day because there were three camaro on the bay lifts.

Originally Posted by KingLT1

A lot of the A8's quirks are in the tuning. Properly tuned it's right up there with a A10 other then the paddle shift response time isn't as fast. GM did a better job with the tuning on the A10.

One thing I would do is reset the shift adapts on the A8 and let it relearn. Especially if you bought the car used and/or had the fluids and/or converter changed. Dealership can do it by request...so can HPtuners if you have it or know somebody that does.

[arpad_m]

Originally Posted by Fiyero88

Not the king of anything and also didn't weigh in on anything just telling you what the master mechanic said �� your crummy attitude is what makes this forum kinda crummy tbh. Also why weigh in on a recall post if there's nothing wrong with yours?

Hmm, my attitude is crummy, interesting... he gave specific advice on tuning, trying relearn, and alluded to fluid and/or torque converter replacement.

Not reacting to a recall post either, it was a "do nothing" TSB post in this lawsuit thread. I also mentioned the relearn earlier, but of course you're free not to try and just go with what the master mechanic said (...but how will that help you exactly?)

[Fiyero88]

This is from GM Authority:

Numerous class-action suits have been filed against GM over its 8L45E and 8L90 eight-speed automatic transmissions in recent years. The automaker sought to have one of these suits thrown out last August, claiming the transmission problems are related to a design defect and not a manufacturing defect. GM’s vehicle warranties only cover manufacturing defects with parts and components and not design defects. Most of these suits claim all vehicles with these eight-speed transmissions are defective, which would imply a design defect and not a manufacturing defect.

This latest class-action suit calls on GM to reform its warranties to address these transmission problems and also issue a recall for affected vehicles.

The full list of affected vehicles in this class-action suit includes:

2015-2019 Cadillac Escalade/Cadillac Escalade ESV
2016-2019 Cadillac ATS
2016-2019 Cadillac ATS-V
2016-2019 Cadillac CTS
2016-2019 Cadillac CTS-V
2016-2019 Cadillac CT6
2015-2019 Chevrolet Silverado
2017-2019 Chevrolet Colorado
2015-2019 Chevrolet Corvette
2016-2019 Chevrolet Camaro
2017-2019 GMC Canyon
2015-2019 GMC Sierra
2015-2019 GMC Yukon/Yukon XL

[PnCRedJwl2SS]

Originally Posted by Fiyero88

Just left the dealership. They said it's completely normal and the masterechanic came out and said" Chevy designed the A8 poorly, they didn't put a release valve on the A8 so the hydraulic fluid builds up in the mornings and eventually releases causing the car to lunge forward or hard shift. I asked him if it would bother anything and he said Chevy says no it won't ruin the engine. Then he said they designed the A10 to eliminate that problem. But the guy said he's already had headaches with customers complaining about the A10 and he said the A10 will have loads of problems down the line. So basically he's saying that these torque converters are trash. I actually trust him because he works on them all day and really explained to me why the A8 is no good.

This doesn't ring true to me. I have the A8. I had the shudder and eventually got the TC replaced under warranty and new fluid. This all happened between roughly 20k-30k miles (if I recall correctly).

This fixed my issue completely and I have had no recurrence. I'm now over 72k miles. No tuning on my car and I have no hard shifts at all. The transmission has been great since and is truly a beast. I would not hesitate to buy another A8 vehicle if I were i in the market.

The concerns about this transmission are, in my opinion, overblown. Once the fluid is replaced and (in cases where it was damaged) the TC is replaced, it's rock-solid.