Replaced my transmission thermostat with a lower temp thermostat

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

BlaineBug

Full Access Member
Joined
Dec 29, 2019
Posts
1,129
Reaction score
628
Just my opinion but I believe most of the companies added them as a way to squeeze out every fraction of mpg they could get to appease the epa. Same with all of this cylinder deactivation stuff. Even an extra .10 mpg doesn't seem like a lot to one person(one vehicle), but add that up over the millions of vehicles that company produces it looks a lot better to the epa.

Transmissions went years and years without thermostats in them and at least for me I've never heard of one failing because of too cold of fluid. I have heard of a lot of them "burning up" from too hot of fluid though.
That is precisely it. Every single "emissions reducing" or "efficiency improving" component added to engines has reduced reliability.
 

15burban

Member
Joined
Dec 8, 2023
Posts
71
Reaction score
115
Location
Wisconsin
That is precisely it. Every single "emissions reducing" or "efficiency improving" component added to engines has reduced reliability.
All while making the vehicle itself more expensive to purchase. Someone had to spend time to engineer, design, and manufacture all of these parts or systems and there's no way gm, Ford, dodge, etc are footing the bill for it.
 

BlaineBug

Full Access Member
Joined
Dec 29, 2019
Posts
1,129
Reaction score
628
All while making the vehicle itself more expensive to purchase. Someone had to spend time to engineer, design, and manufacture all of these parts or systems and there's no way gm, Ford, dodge, etc are footing the bill for it.
You will own nothing and be happy. The "transition" to electric vehicles is a transition towards the elimination of private modes of transportation. See the recent Euroscum Union proposal to ban the repair of vehicles 15 or more years in age. As they say, "transitory."
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
23,729
Reaction score
34,705
Location
Stockton, Ca.
Has anyone tried replacing the plunger rod inside the valve with a slightly different length rod to reduce the regulating temperature? (Assuming you have a valve not too corroded to work with). It appears to me that would be an easy and free solution to reducing the opening temperature.
I am thinking of replacing the rod with a slightly longer rod fabricated from a drill bit shank of the correct diameter. I might start at about 1/16" longer to see how much that would change the minimum temperature.
The consensus I have read about transmission temperature seems to indicate about 160 degrees is ideal. That correlates with the 158 degree opening temperature of the newer GM part.
For us that live in colder winter climates, we want the fluid to warm up to operating temperature quickly and not remain too cold. That is something that won't happen if we just bypass the thermostat. After all, GM wouldn't have gone to the expense of adding a thermostat unless there was an advantage to it. Simply bypassing the thermostat doesn't make sense to me.
on my 18 it gets plenty hot without a thermostat, unless you live in -00 or less degree weather 24/7 then it won't ever be a problem
mine has no thermostat, additional 40k cooler, deeper trans pan with 3 extra qt's and it still hit's 190 if I push it
typical temps on mine is around 145-165 but I can make it go higher.
stock it was hitting 210-220 driving normal (for me) which would be like you are 30 minutes late to your own funeral for others.

my 2012 has the same setup, winter time it will sit at the same temps 145-165, but in the summer even just idiling it will sit at 180 and will flucuate up/down a bit depending on how I drive anywhere from 165-190, I did have it hit 225 once up at high elevation and slow traffic around 6000-8000ft and 85deg ambient
I did have to move the trans cooler from in front of the radiator because it was making the engine run hot

all of the above probably does not apply to all of you that drive normal or like gramma with no where to go and no place to be in the gazillion hours and persist to drive the speed limit with no care in the world and could care less about all the traffic behind you.
 

15burban

Member
Joined
Dec 8, 2023
Posts
71
Reaction score
115
Location
Wisconsin
proposal to ban the repair of vehicles 15 or more years in age.
Must be made up by a bunch of angry wives whose husband's spend too much time out in the garage/shop "fixing" things that aren't broken. My wife might be the leader in that push.
 

BlaineBug

Full Access Member
Joined
Dec 29, 2019
Posts
1,129
Reaction score
628
on my 18 it gets plenty hot without a thermostat, unless you live in -00 or less degree weather 24/7 then it won't ever be a problem
mine has no thermostat, additional 40k cooler, deeper trans pan with 3 extra qt's and it still hit's 190 if I push it
typical temps on mine is around 145-165 but I can make it go higher.
stock it was hitting 210-220 driving normal (for me) which would be like you are 30 minutes late to your own funeral for others.

my 2012 has the same setup, winter time it will sit at the same temps 145-165, but in the summer even just idiling it will sit at 180 and will flucuate up/down a bit depending on how I drive anywhere from 165-190, I did have it hit 225 once up at high elevation and slow traffic around 6000-8000ft and 85deg ambient
I did have to move the trans cooler from in front of the radiator because it was making the engine run hot

all of the above probably does not apply to all of you that drive normal or like gramma with no where to go and no place to be in the gazillion hours and persist to drive the speed limit with no care in the world and could care less about all the traffic behind you.
What brand pan are you using on the 2018? Is it the 6 speed? I'd love to have a pan with a drain plug.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
23,729
Reaction score
34,705
Location
Stockton, Ca.
What brand pan are you using on the 2018? Is it the 6 speed? I'd love to have a pan with a drain plug.
Yes 6spd B&M 70392
surprised they are in stock, 1st one I had to wait 3 months for it, 2nd one was a little faster almost 2 months
add's 2qt extra capacity, I keep getting these mixed up with a different model for the 8sp


 
Last edited:

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
23,729
Reaction score
34,705
Location
Stockton, Ca.
Thank you. That's pretty damn pricey for a pan.
I
Thank you. That's pretty damn pricey for a pan.
man, I still had the wrong part number it is a 70392
and thanks to Jo yes the price has gone up, my invoice was $297 delivered from Holley (they own several big brands)
amazon has it for $354 if you have a business account, otherwise +tax
this place has it for a slightly less $323

70392.JPG
 

Forum statistics

Threads
129,253
Posts
1,812,883
Members
92,355
Latest member
Laurents10
Top