TFL Silverado Overheats

[f8l vnm]

This is interesting with only towing about 7k for it to over heat.  I remember a little while back on these forums there was a discussion about the trans cooler ( and lack there of)  any longer on the Trucks. In your opinion is this all due to the Trans cooler ?

( FYI for some of you homers , the Ford overheated too but at least that was a little closer to the rated towing capacity. 

I also think This hot weather is baking some of the US . MY personal 6.2 2019 Sierra has been pretty darn good when i have hauled big loads up hills ( but not towing , rather payload hauling) 

 

 

 

Edited July 20, 2021 by f8l vnm

[Greyhound6.2]

I took my buddies and my SXS's from St louis to Moab Utah last year at the end of august the weather was hot A.F. but did not have any issues with heating up. Mine is a 6.2 max tow and hauling 7K+ lbs. 2 sxs on the trailer plus a bed full of luggage, spare parts and tools. we went through colorado springs / monarch pass ( i think) on the way there as 70 was closed due to fires, took 70 back through denver on the way home and didn't have any temperature or power problems either way. 

Edited July 20, 2021 by Greyhound6.2

[Silverado4x4]

I would pretty much expect it to get hot due to the steep uphill at 25mph in 90+ degree heat trans shifting alot and very little air blowing through the cooler.

[Chebby]

I thought I read that it got up to 300°F. Crazy. It seems everyone is going to higher transmission operating temps, around 200°F. I don’t understand not having an external air cooler up front in addition to the oil heat exchanger on the transmission itself. 
 

Do they think we all just use our half tons for gettin groceries? 

Edited July 21, 2021 by Chebby

[luke1333]

How many miles did it have when they started towing? Owners manual says do not tow for the first 500 miles. Odometer shows 519 miles in video curious if that has something to do with it

[Amcguy1970]

11 hours ago, Chebby said:

I thought I read that it got up to 300°F. Crazy. It seems everyone is going to higher transmission operating temps, around 200°F. I don’t understand not having an external air cooler up front in addition to the oil heat exchanger on the transmission itself. 
 

Do they think we all just use our half tons for gettin groceries? 

 

Unfortunately most do, hence the massaging seats and 22" wheels and leveled stances; it is an image purchase by many...

 

Tyler

Edited July 21, 2021 by Amcguy1970

[KARNUT]

I remember after buying my 01 GMC 1/2 ton. I dueled  it. When home loaded up wife and luggage, hooked up to a uhaul car carrier. I loaded with a replacement part that  was 3 thousand lbs. My break in and trip started. The trip was from the Houston area over the Colorado passes to north California. Dropped off part. South California to pick up broken part. Interstate 10 home. The only difference between this and other trips I didn’t have time to install my tool box and tools. I never had an over heat problem. This 01 wasn’t anything special. Didn’t have a towing package or gear.   I would think they’d be tougher now. Guess not.

[f8l vnm]

I still think this is a random isolated case as i have never had any issues with over hearing on any of my own personal GM trucks and then 50+ GM Trucks we have in our farm fleet. 

One thing i don't know is , did they really take the trans cooler out ?

[calgator73]

I would venture a guess that on steep grades and very low speeds like they were driving they would be better served in four low to keep engine RPM up. This keeps the hydraulic pump in the transmission spinning faster and pushing more fluid.

From owners manual:
4-low
This setting engages the front axle and delivers extra torque. Choose 4 low when driving off-road in deep sand, deep mud, or deep snow, and while climbing or descending steep hills. While driving in 4 low, keep vehicle speed below 72 km/h (45 mph).

[Dirk13]

1 hour ago, calgator73 said:

I would venture a guess that on steep grades and very low speeds like they were driving they would be better served in four low to keep engine RPM up. This keeps the hydraulic pump in the transmission spinning faster and pushing more fluid.

From owners manual:
4-low
This setting engages the front axle and delivers extra torque. Choose 4 low when driving off-road in deep sand, deep mud, or deep snow, and while climbing or descending steep hills. While driving in 4 low, keep vehicle speed below 72 km/h (45 mph).

Why use 4 low just to keep engine rpm up?? Couldn’t you just do that by manually selecting gears?

 

Whats the manual say about driving in 4 low on dry pavement?

[BigDog88]

I’ve got a Max tow 2020 6.2 and pull a heavier travel trailer 8500# with more drag because of surface area and have pulled the Ike gauntlet and other step pulls in Colorado last summer and never had that problem.  In fact I was so impressed with how cool the trans stayed. It pulls

the trailer around 150 degrees and never got over 200 on the toughest pulls.  Something wrong with that truck on TFL.  

[f8l vnm]

On 7/21/2021 at 7:25 AM, Amcguy1970 said:

 

Unfortunately most do, hence the massaging seats and 22" wheels and leveled stances; it is an image purchase by many...

 

Tyler

While I agree the half ton has become a family car but at same time these are also GMs money makers. 

[Gangly]

14 hours ago, Dirk13 said:

Why use 4 low just to keep engine rpm up?? Couldn’t you just do that by manually selecting gears?

 

Whats the manual say about driving in 4 low on dry pavement?

4 Low allows your transmission to pump a larger volume of fluid over a given set of time, resulting in more fluid passing through the transmission oil cooler.  If you are traveling in a straight line up a hill, 4 low would be perfectly fine, but like mentioned above you would need to worry about 4 low if driving on a winding concrete road.

[calgator73]

1 hour ago, Gangly said:

4 Low allows your transmission to pump a larger volume of fluid over a given set of time, resulting in more fluid passing through the transmission oil cooler.  If you are traveling in a straight line up a hill, 4 low would be perfectly fine, but like mentioned above you would need to worry about 4 low if driving on a winding concrete road.

I think on sunshine canyon drive it's gravel all the way to the top.  Engine wasn't overheating...just the tranny.   I would have hit 4 low.

[calgator73]

16 hours ago, Dirk13 said:

Why use 4 low just to keep engine rpm up?? Couldn’t you just do that by manually selecting gears?

 

Whats the manual say about driving in 4 low on dry pavement?

See gangly's post....in general yes a lower gear will bring rpms up.  Andre says he was running 25-30 mph on sunshine canyon drive which according to google street view is all gravel to the top.  Maintaining low speeds with a high load, high temp and high altitude would tell me to either speed up and lock in a gear so i'm not lugging or...I'm going into 4-low to allow the whole drivetrain to experience a lower perceived load due to torque multiplication and hope for the best.  I bet that tranny was constantly shifting from 1st to 3rd and back.