10 speed Transmission Hot - Please help

ArthurW · May 28

On 5/26/2024 at 11:43 PM, Grover67 said:

Thought about trying a bypass to see or you just going to let the GM network do its thing? Its a easy swap.

I may be mistaken, but I believe the bypass is part of the valve body on the 5.3 variation of the 10 speed.

Also - follow up question: does anyone notice a whining or whirring sound coming from the transmission? My best explanation is the kind of sound a bad idler pulley would make where it's a grindy/growly/whine. (Mostly whine) It's not super loud, but I can hear it at idle and light throttle when in park/drive, etc. I can't hear it as much on the road but that's likely because the road noise covers it up. I have heard it could be normal, or maybe not. I think a guy at work has a 24 5.3 with the 10 so I may see if I can take his for a run to compare.

Edited May 28 by ArthurW

Ejl923 · May 30

On 5/25/2024 at 11:19 AM, ArthurW said:

On 5/23/2024 at 10:04 AM, Ejl923 said:

I read this whole thread as I just purchased a Silverado 5.3 and certainly has me interested, maybe I missed it does this truck have the max trailering package?

It does not have that package, no.

Good to know, mine does not have max trailering either, would love to help with comparisons anyway i can. Im a decent wrencher, but very new to GM trucks so still getting familiar, only had a month. Just took my maiden tow as a first test, about 30 miles, 3500 lbs travel trailer, mostly rolling hills, avg 50 mph, last 10 miles had 5 decent climbs grade wise about 1 minute each so not exactly taxing but seeing as how they were at the end i expected the trans temp to climb a little. During the entire trip my trans temp stayed around 162 F. not much for you to go on, but im planning to get another longer tow in before my first real trip in july to make sure all is up to snuff.

Edited May 30 by Ejl923

ArthurW · May 30

9 hours ago, Ejl923 said:

Good to know, mine does not have max trailering either, would love to help with comparisons anyway i can. Im a decent wrencher, but very new to GM trucks so still getting familiar, only had a month. Just took my maiden tow as a first test, about 30 miles, 3500 lbs travel trailer, mostly rolling hills, avg 50 mph, last 10 miles had 5 decent climbs grade wise about 1 minute each so not exactly taxing but seeing as how they were at the end i expected the trans temp to climb a little. During the entire trip my trans temp stayed around 162 F. not much for you to go on, but im planning to get another longer tow in before my first real trip in july to make sure all is up to snuff.

Thank you for this, anything helps! Is yours a 5.3 with 10 speed as well?

Mine would've gone well above 162 in 30 miles lol

Ejl923 · May 30

12 minutes ago, ArthurW said:

Thank you for this, anything helps! Is yours a 5.3 with 10 speed as well?

Mine would've gone well above 162 in 30 miles lol

Yes, 5.3, 10 speed, std trailering package, 4x4. Oh and it was 67F outside so not too hot. My Tacoma pulled this trailer in 95F weather for 90 minutes and I think topped at 205F. That had a 5 speed trans with puny atf cooler.
Sorry this is happening and GM should be doing more, doesn’t give me a good feeling about dealing with possible future issues. Anything I can do to help let me know. What is your trans temp just daily driving on a warm day? Mine is around 150-153F

ArthurW · May 30

1 minute ago, Ejl923 said:

Yes, 5.3, 10 speed, std trailering package, 4x4. Oh and it was 67F outside so not too hot. My Tacoma pulled this trailer in 95F weather for 90 minutes and I think topped at 205F. That had a 5 speed trans with puny atf cooler.
Sorry this is happening and GM should be doing more, doesn’t give me a good feeling about dealing with possible future issues. Anything I can do to help let me know. What is your trans temp just daily driving on a warm day? Mine is around 150-153F

Really depends on the length of drive, the longer I drive the hotter it gets, but the rate of increase is a lot slower when I'm not hauling VS when I'm hauling. It just never cools (no fluid coming to the cooler by the looks of things), and just continuously raises the longer I drive/haul.

Generally, probably anywhere from 160-190F just normal driving. I've actually never had this truck on a multi-hour road trip, so I have no idea how hot it'd get just cruising down the highway for an extended period of time. The longest I usually drive uninterrupted in this truck is probably an hour or so down the road (and even then, that is only once in a while) most times its 15-20 minute trips.

ArthurW · June 6

As an update - the second dealer has opted to not touch the truck as they don't have a transmission technician. I guess I'll have to try another dealer. GM support hasn't really been all that helpful with getting an answer.

TrueBlue · June 9

All I can say is that I hope this issue, and this thread costs GM ten times what they would have paid to do the right thing by you Arthur. Keep posting here please. At the very least you're opening the eyes of some who would otherwise have no way of knowing about potential pitfalls of this gen's shortcomings.

ArthurW · June 9

On 6/6/2024 at 5:14 PM, ArthurW said:

As an update - the second dealer has opted to not touch the truck as they don't have a transmission technician. I guess I'll have to try another dealer. GM support hasn't really been all that helpful with getting an answer.

Putting it in perspective, I spent an hour on the phone with GM Support who could help me "find a dealer", and then after quite a bit of discussion "maybe" get me a managerial discount to buy a new truck.

That said, I would still lose 10K on the deal likely because of the fact that I've only owned the truck for about 9 months now.

Man, General Motors really has really dropped the ball on this one. Shame. I'll update as I continue with this process.

ArthurW · June 10

On 6/9/2024 at 3:32 PM, ArthurW said:

Putting it in perspective, I spent an hour on the phone with GM Support who could help me "find a dealer", and then after quite a bit of discussion "maybe" get me a managerial discount to buy a new truck.

That said, I would still lose 10K on the deal likely because of the fact that I've only owned the truck for about 9 months now.

Man, General Motors really has really dropped the ball on this one. Shame. I'll update as I continue with this process.

And another update - spoke with the General Manager from the local dealership, he's going to look into things. I'm not super optimistic, but let's hope.

Steve-2019 · June 10

2 hours ago, ArthurW said:

And another update - spoke with the General Manager from the local dealership, he's going to look into things. I'm not super optimistic, but let's hope.

He has the means to do something for you, "if" he wants to. (Have you bought from this dealership before?)

ArthurW · June 10

13 minutes ago, Steve-2019 said:

He has the means to do something for you, "if" he wants to. (Have you bought from this dealership before?)

I haven't, but if he was to rectify this issue with me I'd likely rescind some of my words and anti-recommendations from them. I have some buying power influence at my employer and I can assure you there is a reason our last two service vehicles were Fords lol.

Ejl923 · June 11

On 6/9/2024 at 11:20 AM, TrueBlue said:

All I can say is that I hope this issue, and this thread costs GM ten times what they would have paid to do the right thing by you Arthur. Keep posting here please. At the very least you're opening the eyes of some who would otherwise have no way of knowing about potential pitfalls of this gen's shortcomings.

as someone who has owned a GM truck for two months and still has 0 brand loyalty to GM, this thread was one of my biggest worries "upgrading" from a Tacoma. Luckily for GM, the Tundra has its own issues and wimpy payloads and decided on a Silverado. But when needing another truck comes around, this will factor for sure.

ArthurW · June 27

Is there any technicians on here? I'm trying to figure out if the thermal bypass valve is something that can be replaced in the valvebody on the transmission (10l80). I know on the 10r80 you can, but curious about GM's.

SFLTruck · June 30

On my 10L80 the bypass is external and on the passenger side of the trans. I'm thinking yours should be the same as the 3.0 because the trans is exactly the same. If you crawl under and take a look you will see the lines (3 of them) on the TBV. Can you take a look ans see?

newdude · June 30

47 minutes ago, SFLTruck said:

On my 10L80 the bypass is external and on the passenger side of the trans. I'm thinking yours should be the same as the 3.0 because the trans is exactly the same. If you crawl under and take a look you will see the lines (3 of them) on the TBV. Can you take a look ans see?

The 10L80 with the 3.0 has this, the gas applications (5.3 and 6.2) with the 10L80 do NOT use this. They have the internal TBV only.

Transmission cooler lines are a whole different animal on the 3.0. Directly on the transmission it has an oil to water heat exchanger, which from there flows to the TBV. When the TBV is closed, it flows back to the transmission until it opens. Once it opens, its transmission to exchanger, exchanger through the open TBV to the aux cooler, then back to the transmission.

So transmission temp is regulated like 3 or 4 ways on the 3.0 diesels. TBV, the cooler at the front of the truck and the heat exchanger which is tied into the cooling system on the truck which is regulated by that active thermal management water valve.

Gas 10 speeds don't use the oil to water heat exchanger either.

Edited June 30 by newdude