Chevy Silverado and GMC Sierra Forum banner
21 - 40 of 57 Posts

·
Registered
2021 GMC Sierra Denali CC 4WD Ultimate 6.2L
Joined
·
5,077 Posts
Friend is a GMC tech and he told me its not uncommon for the temp to read less than 190 on these trucks. Some tests he has to perform call for the temp to be a normal operating temp of 190 before he can do something so he ends up torque braking it so the trans temp comes up. According to him the digital readout on the new trucks in right on the money with his testing equipment.
 

·
Registered
2021 GMC Sierra Denali CC 4WD Ultimate 6.2L
Joined
·
5,077 Posts
In the 1500's at least the trans temp is accessed thru the Driver Information Center (DIC). You can scroll thru varies items and leave the Tran temp on display.

The info is displayed in the window in the tach
note-Today trans temp 77, temp inside my garage is 81. Truck has been sitting since sat.

This is the window that tells you when in AFM mode, V8 changes to V4 and gives a mpg estimated reading.
 

·
Registered
Joined
·
526 Posts
Stop and go really heats it up with all the shifting and the torque converter locking. Especially if you're not really moving much which decreases the trans cooler's ability to cool down. How hot was it outside?
 

·
Premium Member
Joined
·
6,959 Posts
I've noticed the highest temps I see are always when I'm backing up my trailer, up a hill, into my garage. The lowest temps are when I'm cruising down the freeway.
 

·
Registered
Joined
·
51 Posts
straight out of the service manual~> To get the right reading, the fluid should be at normal
operating temperature, which is 180°F to 200°F (82°C to 93°C). wheel/tire size has a lot of influence on the temp also...i see 212ish when summer towing fully loded and gassed.
 

·
Registered
Joined
·
526 Posts
I'm on a fairly heavy wheel/tire combo (33x12.5 on 20s) and I'm also running a 34 gallon tank. Full tank and driving hard (with a custom tune with very firm shifts) on a 90 degree day and I see no higher than 195 degrees. I'm abusing my tranny quite a bit and still haven't seen 200 degrees yet. Maybe it's the tranny cooler that's keeping me cool.
 

·
Registered
Joined
·
8,439 Posts
I wonder if my cooler temps are related to the fact that I use Amsoil's Coolant Boost in the cooling system? It's supposed to be more effective at dissapating heat. I bought it for the engine, but it may be helping the tranny too. Maybe?
 

·
Premium Member
Joined
·
6,959 Posts
^Could be, but we've got to remember, that most of us are running different tranny\engine setups. It sounds like the 1\2 ton 6-speeds run cooler than the 480LE transmissions.
 

·
Registered
Joined
·
526 Posts
starspangled6.0 said:
^Could be, but we've got to remember, that most of us are running different tranny\engine setups. It sounds like the 1\2 ton 6-speeds run cooler than the 480LE transmissions.
Would make sense. I'm running a tranny from 03 while you guys are running 07+. Also, could be due to the fact that my shifts are much much firmer and more frequent than stock as well as the fact that I'm running b&m trick shift fluid so that could play a huge factor in it. Still, I'm not seeing anything above 195 tho.
 

·
Registered
Joined
·
3 Posts
New truck, 1500 miles so far, just pulled a 6500lbs trailer, from MA down to PA, 95 outside temp. DIC reads between 180 as high as 207 for a short while. did use tow/hual mode.
 

·
Premium Member
Joined
·
6,959 Posts
I recently changed out my rear diff fluid- it was overfilled, and who knows how long it's been since it was changed last. I put Amsoil in, and now, the trans temps are running 5-10 degrees lower. It's hard to get a good reading with the little stubby trans temp needle, but I can certainly say that it's running cooler. Hooray!
 

·
Registered
Joined
·
2,258 Posts
EKinMN said:
I wonder if my cooler temps are related to the fact that I use Amsoil's Coolant Boost in the cooling system? It's supposed to be more effective at dissapating heat. I bought it for the engine, but it may be helping the tranny too. Maybe?
The opposite should be true since your engine's radiator is now more efficient and thus dissapates more of its heat through the radiator. This heat would be dissapating right next to the tranny's heat exchanger and thus make it harder to dissapate its heat.

This is all theory of course... :ugeek:
 

·
Registered
Joined
·
8,439 Posts
Theory's of heat transfer is like Physics....and physics give me a headache! :)
 
21 - 40 of 57 Posts
Top