r/Cadillac • u/jhoke1017 • 2d ago

How has GM not fixed the 10-speed?

I genuinely don’t understand how this transmission is so bad? I had the dreaded valve body issue, and instead of waiting on a list 3500 deep, I got a full OEM transmission swap as I am still under warranty.

The new one still occasionally lurches when downshifting, and consistently hunts for gears.

How has GM stayed competitive when their transmissions are just….bad? Even my Ford with the same 10 speed is significantly better.

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u/OldheadBoomer 2d ago

Mine's acting up, 2023 CT4-V. A few days ago, I was driving under 40, let off the gas, and felt it hesitate like I touched the brakes. A few seconds later, it spit out a check engine light and "Reduced acceleration mode" and stayed in 5th gear.

I got home and parked; it was very clunky going into reverse. An hour later, I went out and started it, and took it for a test drive. The check engine light was still on, but it drove normally. I pulled the codes using an OBD II scanner and got a P0700 and P0747.

I have an appointment on the 17th. It's still doing okay, hopefully it will stay that way for a couple more weeks.

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u/MyEasyLemon 1d ago

Hunt-and-lurch plus P0747 almost always means a sticking pressure-control solenoid in the valve body; it’s the same root issue that killed the earlier units, so don’t let the dealer brush it off. Print GM TSB 22-NA-167 and 23-NA-043, drop the car off cold, and ask them to log clutch pressures-heat usually masks the fault. Make sure they pull the pan: if the fluid’s glittery or smells burnt, insist on a new valve body (or complete trans) and the latest TCM flash. Keep a phone video of every flare or slam and note mileage; it gives you leverage with GM Customer Care and, if you’ve got a CarShield policy, it speeds approval. If they still can’t nail it, Easy Lemon 310-361-8647 can start a lemon claim under the 2023 warranty. Stay on them until it shifts clean again.

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u/Particular_Apple_652 1d ago

You seem knowledgeable so let me ask you this…I just got a full trans replacement…what did they replace it with? The same exact thing?