10 speed Transmission Hot - Please help

TrueBlue · January 24

Any updates on your issue Arthur?

ArthurW · February 2

On 1/24/2024 at 11:31 AM, TrueBlue said:

Any updates on your issue Arthur?

Hi, sorry for not checking in.

The other dealer replaced the shutters, but I haven't noticed any noticeable difference yet. It's been consistently -5 and colder (20s in f and colder) and I haven't towed anything so I haven't had an overheat condition since. I have noticed a few rough shifts here and there, and a little bit of a 'hum' coming from the truck in the last few weeks but I credited that to it being cold outside.

Transmission temperature wise it's still been floating in the 150-170 range, but I haven't really worked the truck. Sadly I probably really won't know if it's fixed until I have the opportunity to tow again.

This new dealership seems a lot better to deal with, but I really do still think I have something going on with the truck but I'm not going to burden them with fixes unless I can reproduce the problem.

TrueBlue · February 2

Thanks for the update Arthur. I sure hope you are able to get this ironed out.

ArthurW · April 22

Just as an update - still an ongoing issue. Loaded trailer yesterday with some gravel (4500lbs worth) and within 20 minutes (14 miles) of driving back home from the pit my transmission temperature went from 50C (122F) to 110C (230F). (Only reason it stopped going up was because I got to my destination)

So I'm certain once again it's a lemon, back to the dealer I go.

Edited April 22 by ArthurW

newdude · April 22

4 hours ago, ArthurW said:

Just as an update - still an ongoing issue. Loaded trailer yesterday with some gravel (4500lbs worth) and within 20 minutes (14 miles) of driving back home from the pit my transmission temperature went from 50C (122F) to 110C (230F). (Only reason it stopped going up was because I got to my destination)

So I'm certain once again it's a lemon, back to the dealer I go.

It should get "hot" but if its functioning properly, it shouldn't keep climbing. My 2.7 Turbo HO for example while towing yesterday didn't break past 199-205F. When I hooked up it was like 179F.

What are your temps empty, say after driving around for 30-60 minutes?

Did either dealer actually replace the valve body yet?

Edited April 22 by newdude

ArthurW · April 23

5 hours ago, newdude said:

It should get "hot" but if its functioning properly, it shouldn't keep climbing. My 2.7 Turbo HO for example while towing yesterday didn't break past 199-205F. When I hooked up it was like 179F.

What are your temps empty, say after driving around for 30-60 minutes?

Did either dealer actually replace the valve body yet?

No they haven't yet, one dealer claimed to replace the shutters, but had no effect. It's starting to shift strange too at times. Kinda "mushy" if that makes any sense. I believe this will be my 10th visit for the same issue with zero fixes lol.

The other day I hauled a little tractor (about 3000lbs) about 25KM (15 miles) and the transmission was at 100C (212F) by the time I got home.

Usually with just normal driving I'd probably say in the range of 155-195. I normally only drive to and from work (about 20km (13 miles)) and it's usually about 65-70C (158F) when I get there. (Driving in temperatures around 5-10C (40-50F). Tomorrow I'll actually watch it a little better, it's still pretty cool up in my part of Canada so it takes a little longer for it to heat up it seems. I'll report back tomorrow driving to and from work.

Edited April 23 by ArthurW

ArthurW · May 18

Today after towing my landscape trailer around for a while came home with the transmission around 105C (220ish F) and I took a heat gun and checked the temps at both transmission cooler lines (at the cooler, one on each side), both were about 35C (about 95F) I'm thinking they should be a similar temperature to the actual transmission temperature.

The bottom of the transmission pan was about 90C (averaged out, some spots were over 100, some were around 80) and the cooler lines close to the transmission were about 70C.

Can anyone who is has a infrared gun check the temperature of the lines going out of both sides of the transmission cooler when they get back from a drive where the vehicle gets up to normal operating temperature?

Edited May 19 by ArthurW

TrueBlue · May 22

I must say Arthur, you seem to have the patience of Job...

Ejl923 · May 23

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?

newdude · May 23

On 5/18/2024 at 5:54 PM, ArthurW said:

Today after towing my landscape trailer around for a while came home with the transmission around 105C (220ish F) and I took a heat gun and checked the temps at both transmission cooler lines (at the cooler, one on each side), both were about 35C (about 95F) I'm thinking they should be a similar temperature to the actual transmission temperature.

The bottom of the transmission pan was about 90C (averaged out, some spots were over 100, some were around 80) and the cooler lines close to the transmission were about 70C.

Can anyone who is has a infrared gun check the temperature of the lines going out of both sides of the transmission cooler when they get back from a drive where the vehicle gets up to normal operating temperature?

I'll see what I can do.

At 220F gauge temp (temp is measured in the transmission), those cooler lines at the aux shouldn't be 95F. Good that you are on to something but shame you've had to do the legwork instead of the dealers.

ArthurW · May 25

On 5/22/2024 at 2:06 PM, TrueBlue said:

I must say Arthur, you seem to have the patience of Job...

I don't have a lot of choice at this point, I'm being stone-walled by my local dealer and "GM Support Canada" is about as useless as can be. With this other dealer about 45 minutes away (one way) it's a royal pain to have any kind of service done because I need to have my wife pick me up. That said, I'm going camping this weekend so I expect the truck to go nuclear again and see if they can help me this time.

On 5/23/2024 at 11:04 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.

On 5/23/2024 at 4:59 PM, newdude said:

I'll see what I can do.

At 220F gauge temp (temp is measured in the transmission), those cooler lines at the aux shouldn't be 95F. Good that you are on to something but shame you've had to do the legwork instead of the dealers.

I agree. If you can get me any of those temperatures I'd be super thankful, maybe something to beat the dealer with over the head.

I'll know a little more today as I'm towing my camper about 100ish KM (65ish miles) and I fully expect it to get up to 120C+ (250+F).

I'll check cooler lines when I arrive or on side of the highway if it overheats.

@GMCustomerService

Edited May 25 by ArthurW

Grover67 · May 25

Sounds like the bypass could be hanging up and not allowing it to open to allow fluid to go to cooler coil.

ArthurW · May 26

On 5/25/2024 at 1:08 PM, Grover67 said:

Sounds like the bypass could be hanging up and not allowing it to open to allow fluid to go to cooler coil.

Exactly my thoughts.

After hauling the camper yesterday, transmission was up to 120C after about an hour (around 250F). I checked the cooler lines up front with an infrared and they were at 30C (around 85f) so I think that should be adequate evidence to help the technicians to diagnose and fix this. I have pictures and videos to show them, pray that they listen to me lol.

I also have clunking in the rear end which I assume is something to do with the Leafs that it absolutely driving me crazy so hopefully they can deal with that too. I told the other dealership about it last year as well and they told me they couldn't recreate it. My blood boils just thinking about their incompetence lol.

Pray for me al! Hope that this is resolved soon(ish).

ArthurW · May 26

Just now, ArthurW said:

Exactly my thoughts.

After hauling the camper yesterday, transmission was up to 120C after about an hour (around 250F). I checked the cooler lines up front with an infrared and they were at 30C (around 85f) so I think that should be adequate evidence to help the technicians to diagnose and fix this. I have pictures and videos to show them, pray that they listen to me lol.

I also have clunking in the rear end which I assume is something to do with the Leafs that it absolutely driving me crazy so hopefully they can deal with that too. I told the other dealership about it last year as well and they told me they couldn't recreate it. My blood boils just thinking about their incompetence lol.

Pray for me al! Hope that this is resolved soon(ish).