Jump to content

Transmission temperature

Ahmad Alfilchawi
 Share

Recommended Posts

Kevin Sayer New Member

Kevin Sayer

Posted
Posted

Does anyone know if there is a difference in the V8 vs. The V6 transmission cooling system? I have a v6 and installed the tru-cool thermostat and still saw temps reach 200°f. I recently swapped that out with the "updated" 158° one from GM and that seems to be not much different from the tru-cool one. Am i missing something? Thanks 

newdude Senior Enthusiast

newdude

Posted
Posted (edited)
1 hour ago, Kevin Sayer said:

Does anyone know if there is a difference in the V8 vs. The V6 transmission cooling system? I have a v6 and installed the tru-cool thermostat and still saw temps reach 200°f. I recently swapped that out with the "updated" 158° one from GM and that seems to be not much different from the tru-cool one. Am i missing something? Thanks 

 

 

V6 doesn't have an auxiliary cooler.  Its transmission to the cooler inside the radiator and then back.  

 

V8s have an aux cooler out at the front, its the top 1/4 of the AC condenser.  Also, 14-earl6 16 V8 the lines go transmission to radiator, radiator to aux and then aux to transmission, where late 16-19 don't go through the radiator at all, so the early trucks run warmer like the V6 do and the later trucks run cooler than both.  My 19 old body with the Surecool on a hot day would barely crack 140F, and with the GM updated TBV installed it would hit like 160F max on a hot day.  

Edited by newdude
Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted (edited)
2 hours ago, Kevin Sayer said:

Does anyone know if there is a difference in the V8 vs. The V6 transmission cooling system? I have a v6 and installed the tru-cool thermostat and still saw temps reach 200°f. I recently swapped that out with the "updated" 158° one from GM and that seems to be not much different from the tru-cool one. Am i missing something? Thanks 

 

1 hour ago, newdude said:

V6 doesn't have an auxiliary cooler.  Its transmission to the cooler inside the radiator and then back. 

 

The water temperature of the cold side radiator tank is the limit. With a factory 207 F water thermostat throttling at perhaps 210 F the cold side temperature will depend on the ambient air temperature and air flow. Air flow is typically at its peak between 50 and 55 mph. (Second chart below).  On a hot day let's say you get a 30 degree drop hot side to cold. If you are starting at 210 F the cold tank is 180 F. 

 

The cold side and the ATF flow in counter current directions. This means the ATF can never get as cold as the cold-water side. This is the 'approach temperature'. Typically, and roughly 20 degrees so now you ATF can get cooler than 200 F. 

 

Won't matter what temperature the ATF thermostat is set at if that temperature is below this number. Wide open is wide open. 

 

Okay so you have two options. Colder water, which you get with a colder water thermostat and/or a larger radiator OR a secondary air to air ancillary cooler in series and after the cold tank OR a really large air to air and remove the cold side from the loop. 

 

That last option has a small problem. It blocks air flow from both the radiator and the AC condenser. Fans run more and AC efficiency suffers. 

 

Katech has a 174 F water thermostat that is a five-minute drop fit into the factory housing. That alone will cool the ATF about 30 degrees on a 85-degree day. You will still run out of cooling on hotter days, driving faster than 55 or towing/hauling at the limit and worse the more of these you stack. It is, after all, a load based system. 

 

This is the temperatures my V6 runs at 55 mph with a 170 F Reisch Racing thermostat and the 158 F TBV. Not a drop in but for your edification. You see where it runs out of throttling range of the thermal bypass valve (TBV). 

 

image.thumb.png.9d7c1ba48840a686b4ff7aad40cbf406.png

 

If you drive faster or slower than the target window the temperatures will rise (below chart) requiring yet again additional cooler. 

 

image.png.aacd1d05eee8741dd2fe83773180bfcc.png

 

I'm going to take advantage of a small radiator leak and replace it with the slightly larger GM-21902 NHT unit. Should increase the temperature drop over the radiator which should be of benefit on hotter days. My aim is to keep the TBV throttling on the hottest days I may drive in. That may mean I add a secondary cooler as well. But one step and check at a time. 

 

 

Edited by Grumpy Bear
  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • kr477
      Forward collision and lane keep assist still a problem on 2022 refresh?

      By kr477 · Posted

      I am sorry if this was misleading. That was a document attached to our most recent work order number (Doc# 7105804) that summarized all the current updates. These programs were ‘redone’ in the past but these versions dated 4/1/2016 were the ones that actually made all of the problems disappear. These programs were relayed to the dealer from the technical services group at GM. Here is the exact wording on the last work order:   “Front view camera reprogramming with SPS. A new version of FCM software was released to the service dept. In addition to providing general robustness and stability enhancements, this update includes all enhancements from previous software version releases. SPS camera and calibrate camera. OLH to perform extended camera relearn procedure after camera calibration. Would not take with first GDS learn. Front camera SPS – BDYZ333157450 GDS2 – camera road calibration performed 2810835 Front view camera reprogramming with SPS LT 0.6 OLH – extended camera relearn procedure OLH LT 1.5”   I got the truck back on 4/8 – since that time it has been great no problems whatsoever. The lane keep assist, active cruise control and AEB all work very well around town and at highway speeds up to 80mph. During this time I had been away for a week and purposely let the battery sit without a batter tender. Even with the battery a bit lower there were no problems exhibited. I really think this one has it fixed after dealing with these issues over a couple of years. These new programs and relearn process when completed seem to make all the parts (and newer replacement parts) ‘talk’ to each other without any glitches. Hope this helps
    • mysery1
      Navigating senior years.

      By mysery1 · Posted

      I turned 72 today. My day began with a trip to the pharmacy to pickup meds for me and the dog and then a stop at my chiropractor before heading home. Once home I started the job of replacing the rear brake pads and one rotor on our 2018 Silverado which will probably end up taking me 3 days to finish, gotta pace myself you know. Sometimes I question myself on why I still do most of my own repairs but if I wasn't then it's more than likely I would be sitting in front of the TV all day. It seems like the list of things I need to do gets longer no matter what I accomplish. I'm not complaining but being retired was so much easier when I was 62.   Peace
    • davester
      2021 with Intermittent AC Cooling Issues

      By davester · Posted

      google "bathub failure curve". Basically, any part of the vehicle can fail at any time.  It starts off as being more likely (early failure), then the failure rate goes down (but does not go to zero), then it goes up over time because it wears/ages out.
    • Grumpy Bear
      Winter Returned

      By Grumpy Bear · Posted

      I went from every other day to about once in five since the rain abated. I'm not unhappy about that. Took most of the month for the ditches to dry enough to mow. 
    • txab
      Navigating senior years.

      By txab · Posted

      Good for you and her!   Lots of brushing and grooming to be done

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...