RevMax 8 speed thermostat bypass

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.

crazykid1994

Senior Member
Joined
Sep 21, 2013
Posts
5,040
Reaction score
4,963
Location
Florida
Ram Year
2017
Engine
Hemi 5.7
Had weather down in the upper 40s here (cold for south Florida…) and the trans would barely get to 100° and wouldn’t maintain anything over 100° unless I was driving on the highway. So decided to try something and parts have started to arrive. I will be installing a 145° inline thermostat. Need to get a proper caliper to measure the OD on the trans fluid lines. Seem to be 1/2” which is recommended to use -8an tube sleeves and nuts. Parts should be here sometime in February but the thermostat has already arrived. Comes with -10orb to -8an fittings. I will be flaring the hard line on the trans to connect to the thermostat directly to try to reduce any chances of leaking.
 

Attachments

  • 0BE28A36-B26C-4776-93C9-6A4BD404EB52.jpeg
    0BE28A36-B26C-4776-93C9-6A4BD404EB52.jpeg
    214 KB · Views: 11
OP
OP
W

Wild one

Senior Member
Joined
Jan 17, 2016
Posts
13,723
Reaction score
23,391
Ram Year
14 Sport
Engine
5.7
Had weather down in the upper 40s here (cold for south Florida…) and the trans would barely get to 100° and wouldn’t maintain anything over 100° unless I was driving on the highway. So decided to try something and parts have started to arrive. I will be installing a 145° inline thermostat. Need to get a proper caliper to measure the OD on the trans fluid lines. Seem to be 1/2” which is recommended to use -8an tube sleeves and nuts. Parts should be here sometime in February but the thermostat has already arrived. Comes with -10orb to -8an fittings. I will be flaring the hard line on the trans to connect to the thermostat directly to try to reduce any chances of leaking.
I'd use a ferrule compression fitting on the cooler lines Kris,then make up short flexible lines to connect everything together.
These are overkill,but should never give you any issues with leaking.


 

crazykid1994

Senior Member
Joined
Sep 21, 2013
Posts
5,040
Reaction score
4,963
Location
Florida
Ram Year
2017
Engine
Hemi 5.7
I'd use a ferrule compression fitting on the cooler lines Kris,then make up short flexible lines to connect everything together.
These are overkill,but should never give you any issues with leaking.


As nice as those may be I’ll be flaring the lines for a hard connection instead of a compression fitting. May still end up using short sections of hose depending on where I finalize my decision to mount the thermostat.
 

joesstripclub

Senior Member
Joined
Dec 13, 2019
Posts
428
Reaction score
521
Location
Lees Summit, MO
Ram Year
2021 2500 PW
Engine
Hemi 6.4
Had weather down in the upper 40s here (cold for south Florida…) and the trans would barely get to 100° and wouldn’t maintain anything over 100° unless I was driving on the highway. So decided to try something and parts have started to arrive. I will be installing a 145° inline thermostat. Need to get a proper caliper to measure the OD on the trans fluid lines. Seem to be 1/2” which is recommended to use -8an tube sleeves and nuts. Parts should be here sometime in February but the thermostat has already arrived. Comes with -10orb to -8an fittings. I will be flaring the hard line on the trans to connect to the thermostat directly to try to reduce any chances of leaking.
I forget do you have grill shudders deleted? Even at below freezing temps I still get close to 100 degrees on my less than 10 mile drive to work but i have full shudders.
 

joesstripclub

Senior Member
Joined
Dec 13, 2019
Posts
428
Reaction score
521
Location
Lees Summit, MO
Ram Year
2021 2500 PW
Engine
Hemi 6.4
I did a decent test a couple weeks ago. Rented 4 powder sleds and took them up to Vail Pass. Basically ran the Ike Gauntlet on the way back if you are familiar with TFL's towing test. Was running about 65 up I70 toward the tunnel and looked down at temps, Oil was cooking at 265 but Trans held nicely in the 140s. Only in the mid-40s for ambient temps so it wasnt too crazy out, definitely slowed down a bit to keep the oil temps down though.
20220110_163433.jpg
 

BlownGP

Senior Member
Joined
Feb 10, 2013
Posts
6,079
Reaction score
1,571
Location
Houston/Baton Rouge
Ram Year
2018 RAM Harvest New Holland Blue
Engine
5.7
Had weather down in the upper 40s here (cold for south Florida…) and the trans would barely get to 100° and wouldn’t maintain anything over 100° unless I was driving on the highway. So decided to try something and parts have started to arrive. I will be installing a 145° inline thermostat. Need to get a proper caliper to measure the OD on the trans fluid lines. Seem to be 1/2” which is recommended to use -8an tube sleeves and nuts. Parts should be here sometime in February but the thermostat has already arrived. Comes with -10orb to -8an fittings. I will be flaring the hard line on the trans to connect to the thermostat directly to try to reduce any chances of leaking.

You have no heater at all right? You took it all off.

Are you worried your temps are too low?
 

crazykid1994

Senior Member
Joined
Sep 21, 2013
Posts
5,040
Reaction score
4,963
Location
Florida
Ram Year
2017
Engine
Hemi 5.7
You have no heater at all right? You took it all off.

Are you worried your temps are too low?
Yes. No heater whatsoever. And yes. I’m worried that it’s to low when the temps drop. Hence the 145° thermostat. Says temps should regulate to about 150°. I was fine with the 135-140° temps during summer which is why I chose that temp thermostat. On cold days the trans shifting does feel slightly blocky until around 90° then it smooths out. But in stop and go traffic I can’t hold heat. Does anyone know the stock fitting size at the top of the thermostat housing assembly on the side of the trans? Trying to see if I can just pull the lines back to that point straight from the trans.
 

turkeybird56

Military Vet 1976-1996 Retired US Army
Military
Joined
Aug 2, 2018
Posts
18,758
Reaction score
42,954
Location
Central Texas
Ram Year
2019 Bighorn, 4 X 4, 3.21 rear, Bright Flame Red Pearl Coat, Mopar tonneau cover,Westin Bed rug
Engine
Hemi 5.7
Mustang guys.... They always crying about something.

Sent from my SM-G981W using Tapatalk
BRANDON, did U ever get the clutch lock switch developed for the 5th Gen 5.7's?
 
OP
OP
W

Wild one

Senior Member
Joined
Jan 17, 2016
Posts
13,723
Reaction score
23,391
Ram Year
14 Sport
Engine
5.7
BRANDON, did U ever get the clutch lock switch developed for the 5th Gen 5.7's?
He's been having a bit of trouble with the forum lately,so he might miss this,but you can track him down on his facebook page.


 

HEMIMANN

Senior Member
Supporting Member
Military
Joined
Dec 7, 2020
Posts
6,804
Reaction score
17,090
Location
Minneapolis, MN
Ram Year
2017 2500 Laramie Crew Cab
Engine
6.4L HEMI
Yes. No heater whatsoever. And yes. I’m worried that it’s to low when the temps drop. Hence the 145° thermostat. Says temps should regulate to about 150°. I was fine with the 135-140° temps during summer which is why I chose that temp thermostat. On cold days the trans shifting does feel slightly blocky until around 90° then it smooths out. But in stop and go traffic I can’t hold heat. Does anyone know the stock fitting size at the top of the thermostat housing assembly on the side of the trans? Trying to see if I can just pull the lines back to that point straight from the trans.

So? What happened before they started adding these stupid thermostats? Nothing. Transmission shifts stiffer in cold climates until the oil warms, then it's fine. Add a thermostat just warms it up faster, nothing more. Big deal.

But it is a big deal when it restricts oil flow in hot climates, or fails altogether!
 

crazykid1994

Senior Member
Joined
Sep 21, 2013
Posts
5,040
Reaction score
4,963
Location
Florida
Ram Year
2017
Engine
Hemi 5.7
So? What happened before they started adding these stupid thermostats? Nothing. Transmission shifts stiffer in cold climates until the oil warms, then it's fine. Add a thermostat just warms it up faster, nothing more. Big deal.

But it is a big deal when it restricts oil flow in hot climates, or fails altogether!
This is not able to fail completely hence why I chose this one. If it fails it closes the bypass. There is no restriction on this thermostat. Take a look.
https://www.improvedracing.com/compact-high-flow-engine-transmission-oil-cooler-thermostat.html
 

Attachments

  • A637F4FB-A5DB-4999-A434-CFB57BC5AE1B.png
    A637F4FB-A5DB-4999-A434-CFB57BC5AE1B.png
    288.9 KB · Views: 21

18GSMRam

Senior Member
Joined
Mar 1, 2021
Posts
115
Reaction score
80
Location
FL
Ram Year
2018
Engine
5.7
Had weather down in the upper 40s here (cold for south Florida…) and the trans would barely get to 100° and wouldn’t maintain anything over 100° unless I was driving on the highway. So decided to try something and parts have started to arrive. I will be installing a 145° inline thermostat. Need to get a proper caliper to measure the OD on the trans fluid lines. Seem to be 1/2” which is recommended to use -8an tube sleeves and nuts. Parts should be here sometime in February but the thermostat has already arrived. Comes with -10orb to -8an fittings. I will be flaring the hard line on the trans to connect to the thermostat directly to try to reduce any chances of leaking.
I wish I drove my truck more, been just as cold in Tampa area the last few days to see what mine does. I left the heater, used the block plate and the few times I drove (stop and go traffic, US19 in Pinellas is miserable) it when it was mid/high 50s last week I had no problems getting the trans temps into the 120s (if I remember correctly) but I also tend to drive that thing like a bat out of hell, too much fun not to :shrugs shoulders:

I'll pay more attention these next few weeks cause the temps are supposed to stay down "low" for awhile and I'll drive normal and see what they do. Maybe with the heater still attached it's enough heat to transfer when really cold to get temps up more than with it completely gone?
 
Last edited:

BlownGP

Senior Member
Joined
Feb 10, 2013
Posts
6,079
Reaction score
1,571
Location
Houston/Baton Rouge
Ram Year
2018 RAM Harvest New Holland Blue
Engine
5.7
Yes. No heater whatsoever. And yes. I’m worried that it’s to low when the temps drop. Hence the 145° thermostat. Says temps should regulate to about 150°. I was fine with the 135-140° temps during summer which is why I chose that temp thermostat. On cold days the trans shifting does feel slightly blocky until around 90° then it smooths out. But in stop and go traffic I can’t hold heat. Does anyone know the stock fitting size at the top of the thermostat housing assembly on the side of the trans? Trying to see if I can just pull the lines back to that point straight from the trans.

I see having the heater even with the bypass does proivde some heat to the fluid.

It was 35* this morning and it got into the 130s are so after a 30 minute drive.

I still don't like how jerky the trans is it when it's in 4th or 5th. You let off the gas and coast for a little bit. Then get back on the gas. Definitely not smooth.
 

BlownGP

Senior Member
Joined
Feb 10, 2013
Posts
6,079
Reaction score
1,571
Location
Houston/Baton Rouge
Ram Year
2018 RAM Harvest New Holland Blue
Engine
5.7
So? What happened before they started adding these stupid thermostats? Nothing. Transmission shifts stiffer in cold climates until the oil warms, then it's fine. Add a thermostat just warms it up faster, nothing more. Big deal.

But it is a big deal when it restricts oil flow in hot climates, or fails altogether!
It's a good point because my 09 ofcourse didn't have a heater. If I can remember, the trans still got into the 120s-140s on very cold days.
 
Top