10L80 - filled transmission at wrong temp???

jyi786 said:

Thanks guys. I've scheduled an appointment with my dealer for Monday of next week. Thankfully, they're not THAT bad, and have taken care of me on a few occasions, so I trust them.

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Seamus said:

They figure it out???

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Seamus said:

I was just at the dealer regarding a coolant leak. I happened to speak with the tech who did my friends 2020 10 speed. His is a 3.0 Duramax. His exact words: There are two gears in front of the pump that go bad, subsequently takes out the TC and contaminates the valve body. Said it sounds like marbles when this happens. Said if caught early, replace gears, replace TC, replace valve body, filter, and flush when taken apart. Said if there is any crap in there the TC must be replaced as it cannot be flushed out. ---I asked about my 2018 Escalade and should i be concerned? His response: Never had a bad one here only the 10 speed behind the 3.0 Duramax has issues. They have been a great trans he said. FYI

Side note: They had about 7 2021+ yukons and silverados in there for cams, lifters and bottom ends. Said anything past 2020 is a nightmare motor don't ever consider it. Said thats all they do, its worse than the internet ! LOL When do you ever hear a tech say that??
He owns a 2018 and said delete it and call it a day

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jyi786 said:

Finally an update.

The dealership had my truck since Monday morning. On Tuesday evening, I called them asking for a status update. They said they'd have an update for me later that evening. I never got that update. So I waited until Thursday morning, and called. What do you expect: I got the same old line. They assigned it to a tech, who "could not replicate the issue". So they assigned it to the shop foreman, who also "could not replicate the issue".

Incredulously, I said to them that it is 10000000% easily replicated, each and every time, and offered to come to the dealership again to show them. They agreed, and the shop foreman came along for the ride. Within 30 seconds of me getting into the driver's seat, I reliably replicated the issue, and made sure the tech actually felt the shudder at least 3 times. I asked him if he wanted to bring the scanner so that we can do it again, and he said no need, he had all that he needed to proceed.

Fast forward to this evening, I called them for a status update, and the service advisor reported to me that the shop foreman tech finally indeed did find "codes on the TCM" and on the output graphs which indicate clear TCC slippage. The reasoning they gave for "not believing" what I was telling them is that they have never seen a 10 speed transmission fail, and so were completely caught by surprise that it was indeed the case.

They said based on the diagnosis that it was one of three things:

1. Solenoid/s
2. Valve body
3. Torque converter

They said since it was narrowed down to those 3, they would start doing a more in-depth diagnosis in that order (which is also in order of ascending cost) to determine which of the 3 are the problem, and then provide me with an estimate on repairs early next week.

In hindsight, if they would have just done what I asked them to do, they could have saved me a wasted week, because I literally told them what to do, and expected that it was TCC shudder. Whatever. That is behind me now, and I need to focus on getting this fixed.

@NickTransmissions, what are your thoughts on which of the three it might be? I'm really hoping it's either the solenoid or the valve body, because I know from experience that these two are much less expensive than the actual torque converter.

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NickTransmissions said:

It's hard to say what the root cause is/was but generally speaking, any shuddering is the converter clutch, regardless and once that starts, it is generally not advisable to keep the converter installed...So the only real question is whether the failure started in the converter or was caused by wear in the valve body (TCC priority and/or regulator valve circuits) or TCC solenoid.

Basically what I'm saying is you could be looking at replacing the TC and valve body/TCC solenoid not just one or the other...Shop will pull the valve body down, throw it on the Sonnax vacuum test machine and determine if there's sealing integrity issues with those two valves which are responsible for torque converter clutch function...If weakness is observed, they will want to replace either just the TCC priority valve w/a Sonnax valve or perhaps the entire assembly which will come with a new TCC solenoid. I would be surprised if they only recommend solenoid replacement but what they may do is offer to try that first as it would be the least expensive solution, do a test drive and assess from there whether anything more is necessary.

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jyi786 said:

Ok thank you.

So what do you recommend I do? Sounds like I have 3 options:

1. Let them continue to diagnose and go in order of repair for those 3 components.
2. Ask them to replace the TC/valve body.
3. Ask them to install a completely brand new (or remanufactured) transmission.

I also reached out to another transmission building company and am asking for their quotes on those 3 components.

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