Car and Truck 8 speed temperature differances

[TheEnder]

Honestly that sounds like TOO much of a temperature drop.

Sent from my Pixel 3 XL using Tapatalk

The lower the fluid temperature the longer the transmission lasts.


Sent from my iPhone using Tapatalk

 

[chrisbh17]

The lower the fluid temperature the longer the transmission lasts.


Sent from my iPhone using Tapatalk

ZF published an ideal temperature range, I trust them for the fluid change process, so I trust them for their own specs.

I dont remember the exact numbers (will dig it up shortly and edit this post) but 185 minus 50 is too low.

 

[Riccochet]

Mine is normally 185F and usually sees 190-195 while towing heavy.

 

[TheEnder]

ZF published an ideal temperature range, I trust them for the fluid change process, so I trust them for their own specs.

I dont remember the exact numbers (will dig it up shortly and edit this post) but 185 minus 50 is too low.

ZFs ideal temperature range is strictly for fuel economy numbers, and nothing else but fuel economy numbers.

Yes, the 8 speed will last forever running at 200F, but, it’ll last even longer at a lower temperature. Kinda like with the RFE, running them at Chrysler’s “operating temp” of 180F is okay, but it’ll die quicker than if it runs at 120.


Sent from my iPhone using Tapatalk

 

[Travelin Ram]

Perhaps the 6.4 has a difference in cooling. My truck consistently runs 16x-17x even in temps well over 100 or towing large trailers.

 

[TheEnder]

Perhaps the 6.4 has a difference in cooling. My truck consistently runs 16x-17x even in temps well over 100 or towing large trailers.

i’m not aware of any differences in the truck cooler for the 8 speed, but i know that the cars don’t have fluid heaters but the trucks do. Ive heard of other users having 8sp transmissions that run cooler, so not too far off.


Sent from my iPhone using Tapatalk

 

[TheEnder]

I dont think my trucks ever ran over 185 or so even pulling my trailer
I think my oil takes all the heat from everything else...lol

Do you think the thermostat or what ever its called on the transmission is set on a lower temp on the cars ?

Cars don’t have a thermostat, and i can verify this with my 300.


Sent from my iPhone using Tapatalk

 

[ScLeCo]

Honestly that sounds like TOO much of a temperature drop.

Sent from my Pixel 3 XL using Tapatalk

I have a higher stall converter.

 

[69GWC]

.

 

[Narg]

Are you 100% sure the temp probe in the car was working correctly? Just a thought....

 

[Tracy in IL]

I think your cooler air temps and the lighter weight/better aerodynamics of the Challenger has a lot to do with it.

 

[joesstripclub]

https://revmaxconverters.com/produc...-8hp75-transmission-cooler-thermostat-bypass/

Link for the Thermosat bypass posted earlier. I'm pretty tempted to get this but would but curious to see some other people have it installed and give some feedback. Would you get some sort of CEL on a stock truck?

 

[Rampad]

View attachment 226244
Putting this on my new transmission.

Says : "Option Three (Most Common): Install the warmer blocking plate and brass end plug upgrade and remove the thermostat. This will eliminate the rapid heating from the warming unit and then by also removing the thermostat you can expect up to a 50-70 degree drop in operating temperature. You will also have a 87% increase in cooler flow by using this option as the restrictive thermostat is now removed and the maximum amount of cooler flow is now flowing."

We'll see.

I just purchased mine also, hopefully I get it soon.

 

[Rampad]

https://revmaxconverters.com/produc...-8hp75-transmission-cooler-thermostat-bypass/

Link for the Thermosat bypass posted earlier. I'm pretty tempted to get this but would but curious to see some other people have it installed and give some feedback. Would you get some sort of CEL on a stock truck?

 

[Rampad]

I removed the thermostat valve, I wanted to see what would happen before I installed the revmax retrofit. I have driven about 100 miles since removed and haven't gotten a CEL yet.

 

[Wild one]

Are you 100% sure the temp probe in the car was working correctly? Just a thought....

Yup as this is the 2nd Challenger she's owned with an 8 speed and her old one ran at the same temps as this one does.

 

[chrisbh17]

https://revmaxconverters.com/produc...-8hp75-transmission-cooler-thermostat-bypass/

Link for the Thermosat bypass posted earlier. I'm pretty tempted to get this but would but curious to see some other people have it installed and give some feedback. Would you get some sort of CEL on a stock truck?

If you read the install instructions, they reference 2 other options...one of which "only" drops 20 degrees of temp.

20 degrees would make me feel better....while I get that some of the suggestions are strictly for mpg, I still think there is something to warmer fluid being better than colder. Just like why I go easy on my engine until the oil gets above 130 or 140.

 

[Arth]

I noticed in my 2018 1500 with the Ecodiesel my trans temps would run 190-195 on the highway. On really hot days it would climb to 200. The transmission in that truck would heat up quick. Unloaded 85 mile round trip. I usually run about 80 or so.

On my 2021 Ecodiesel I am seeing 185 max. It takes a while before transmission temps start to rise too. Haven't towed with it yet.

 

[Rampad]

If you read the install instructions, they reference 2 other options...one of which "only" drops 20 degrees of temp.

20 degrees would make me feel better....while I get that some of the suggestions are strictly for mpg, I still think there is something to warmer fluid being better than colder. Just like why I go easy on my engine until the oil gets above 130 or 140.

I couldn't decide which option I wanted, so that's why i removed the thermostatic spring valve behind the plastic end plug. This is an observation since the removal.

The valve controls the flow from both the heater and the cooler. When removed the transmission gets FULL flow heat and FULL flow cooling.When the vehicle is under a light load(driving down the highway) the cooling effect will overcome the heater and you will have lower than normal temps. But! The effect can be reversed if the vehicle is under load (towing or driving aggressively). The heat from the engine will combine with the heat created by the transmission and over come the cold flow from the trans cooler. Your transmission temps will continue to go up as the engine temp goes up.

That's why Revmax gives you options, it depends on how much load you will put on the transmission. If you drive the **** out of the truck then you want it to cool, but if you drive alot of highway and want efficiency then you want the higher temps.

Now the gamechanger is the blocking plate, because this takes the heater out of the equation. No more unwanted heat from the engine coolant

 

[ZookaTx]

2019 Power Wagon, towing TT and cargo trailers thru the Rockies in Colorado and Wyoming, on I-80 doing 80 MPH, and in Texas summer temps. Never over 180.