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
5,063
Reaction score
5,064
Location
Florida
Ram Year
2017
Engine
Hemi 5.7
I thought about pulling the coolant lines,but i was thinking of trying to keep them in decent shape.Your way definitely is easier though,lol. I kind of want to keep the hoses intact,thinking somebody might need a set down the road
Couldn’t pull them without cutting. Looks like they are installed to the engine transmission assembly prior to install in the frame. It wraps the engine mount.
 
OP
OP
W

Wild one

Senior Member
Joined
Jan 17, 2016
Posts
23,826
Reaction score
54,856
Ram Year
14 Sport
Engine
5.7
Couldn’t pull them without cutting. Looks like they are installed to the engine transmission assembly prior to install in the frame. It wraps the engine mount.

There's a bolt on the top of the bellhousing that holds them in,That's the one that's a bit tougher to get to,but it wasn't bad with a couple long extensions and an impact gun.I had the lines out once when i replaced the tranny ,but that doesn't mean i'm looking forward to removing them again. I actually should have deleted them at that time,but back then i was still worried about the 3 year warrenty on the new tranny,so like a dumb-ass i hooked everything back up,aarrgghh,lol
 

crazykid1994

Senior Member
Joined
Sep 21, 2013
Posts
5,063
Reaction score
5,064
Location
Florida
Ram Year
2017
Engine
Hemi 5.7
There's a bolt on the top of the bellhousing that holds them in,That's the one that's a bit tougher to get to,but it wasn't bad with a couple long extensions and an impact gun.I had the lines out once when i replaced the tranny ,but that doesn't mean i'm looking forward to removing them again. I actually should have deleted them at that time,but back then i was still worried about the 3 year warrenty on the new tranny,so like a dumb-ass i hooked everything back up,aarrgghh,lol
Yea I got that out no issue but the hoses were hitting the motor mount and the frame at the same time. Without the trans in place would have been easier to remove them. Hopefully my refill goes well tomorrow. Trucks sitting back together. Just have to do the fill process. Should be easy with no heater block and no thermostat.
 
OP
OP
W

Wild one

Senior Member
Joined
Jan 17, 2016
Posts
23,826
Reaction score
54,856
Ram Year
14 Sport
Engine
5.7
Here's the level checking procedure if you need it. I think i'd still do all the steps,but with-out the thermostat,you shouldn't have to double check it again after driving it long enough to get the tranny warm enough to open the thermostat.Plus the tranny won't warm up 122F as fast,which should give a guy a little more breathing room,on running it through the gears and still getting the fill plug out,before the tranny hits 122F.

IMG_3383 (2).JPG
 

crazykid1994

Senior Member
Joined
Sep 21, 2013
Posts
5,063
Reaction score
5,064
Location
Florida
Ram Year
2017
Engine
Hemi 5.7
Here's the level checking procedure if you need it. I think i'd still do all the steps,but with-out the thermostat,you shouldn't have to double check it again after driving it long enough to get the tranny warm enough to open the thermostat.Plus the tranny won't warm up 122F as fast,which should give a guy a little more breathing room,on running it through the gears and still getting the fill plug out,before the tranny hits 122F.

View attachment 235311
Yes. Thank you. I was going to ask for that.
 

grizzstang

Senior Member
Joined
Apr 26, 2017
Posts
1,856
Reaction score
2,914
Location
Calgary, Alberta Canada
Ram Year
2017
Engine
Hemi 5.7
You have to block both holes. The plate is way easier,but you have to make sure you scrape the silicone off the heat exchanger,then apply a good bead of RTV silicone to the O-rings or the plate,when you install the block-off plate,or else it could leak.I don't think Khristopher applied any RTV to the O-rings or plate when he installed it the first time around,which might be a contributing factor to his leaking.The downside to doing it the way Khristopher and i are doing it,is there's no reversing the procedure Shaun,with the block off plate,you can easily go back to stock if you don't like it

It looks like there are 3 holes in the thermostat bore from the pics and if the thermostat expands when it is hot wouldn’t you just need to block the very bottom hole in the bore?


Sent from my iPhone using Tapatalk
 
OP
OP
W

Wild one

Senior Member
Joined
Jan 17, 2016
Posts
23,826
Reaction score
54,856
Ram Year
14 Sport
Engine
5.7
It looks like there are 3 holes in the thermostat bore from the pics and if the thermostat expands when it is hot wouldn’t you just need to block the very bottom hole in the bore?


Sent from my iPhone using Tapatalk

You don't have to block the bore itself,all you need to block are the 2 holes in the side of the fluid router ,if you look close at the holes that we've blocked ,they become external holes with the heat exchanger removed,they are the actual bypass holes,that lets tranny fluid circulate through the heat exchanger. The plate slides in between the fluid routing piece and the heat exchanger,doing the same thing except with a plate to block the holes.The beauty of the plate is you can easily return to stock if you want
 

grizzstang

Senior Member
Joined
Apr 26, 2017
Posts
1,856
Reaction score
2,914
Location
Calgary, Alberta Canada
Ram Year
2017
Engine
Hemi 5.7
Yes but since I still have powertrain warranty I was looking to block a hole in the thermostat bore so everything still looks stock but I get the same effect. I will have to look back but someone was going to machine a plug to accomplish this very thing. If I figure out how to do this then I don’t have to spend 200 bucks on the RevMax kit.

Edit: Found it. caulk04 was talking about this.

Sent from my iPhone using Tapatalk
 
Last edited:

Different Drummer

Senior Member
Joined
Oct 20, 2020
Posts
612
Reaction score
664
Location
North East
Ram Year
2017
Engine
Pentastar V6
Yes but since I still have powertrain warranty I was looking to block a hole in the thermostat bore so everything still looks stock but I get the same effect. I will have to look back but someone was going to machine a plug to accomplish this very thing. If I figure out how to do this then I don’t have to spend 200 bucks on the Revmax kit.


Sent from my iPhone using Tapatalk
I think you guys are talking about different holes in different areas.
I believe that grizzstang wants to block one hole in the spring operated thermostat channel that sits under the plastic plug. Wild one is talking about two holes that mate to the heat exchange unit.
I will apologize ahead of time for butting in if I am wrong.
Carry on, this is interesting.
 
OP
OP
W

Wild one

Senior Member
Joined
Jan 17, 2016
Posts
23,826
Reaction score
54,856
Ram Year
14 Sport
Engine
5.7
I think you guys are talking about different holes in different areas.
I believe that grizzstang wants to block a hole in the spring operated thermostat channel that sits under the plastic plug. The one that transmission fluid passes through. Wild one is talking about the engine coolant passage holes that mate to the heat exchange unit.
I will apologize ahead of time for butting in if I am wrong.
Carry on, this is interesting.

I think you're right DD, i didn't realize he wanted to do it with a plug,i was stuck on thinking he wanted to remove the heat exchanger to,that's my mistake,lol.
 

Different Drummer

Senior Member
Joined
Oct 20, 2020
Posts
612
Reaction score
664
Location
North East
Ram Year
2017
Engine
Pentastar V6
I think you're right DD, i didn't realize he wanted to do it with a plug,i was stuck on thinking he wanted to remove the heat exchanger to,that's my mistake,lol.
LOL, Yeah, I am sort of in Grizzstang's position. Still on warranty for a while. Damned if I will buy the whole thing though to get the brass end fitting. Oh wait, do I remember something waaaay back about just removing the thermostat really didn't do much? Maybe I am peeing up a drain pipe. LOL
 

grizzstang

Senior Member
Joined
Apr 26, 2017
Posts
1,856
Reaction score
2,914
Location
Calgary, Alberta Canada
Ram Year
2017
Engine
Hemi 5.7
You are right. You remove the thermostat and the bulk of the fluid still wants to flow through the heater instead of the cooler. That is why I am looking to at least partially plug the hole to the heater so it will flow to the cooler.


Sent from my iPhone using Tapatalk
 

joesstripclub

Senior Member
Joined
Dec 13, 2019
Posts
784
Reaction score
1,149
Location
Kansas City, MO
Ram Year
2021 2500 PW
Engine
Hemi 6.4
I still need to order some fluid and get my kit installed. I've been following to see how the heat exchanger removal went. Kinda seems like more work and demo then I want to do at this point, but if it ever gets a leak or has any issues its a goner. One of these days I will update on the temps with the kit installed.

Anyone have a better source for Redline trans fluid than amazon?
 

crazykid1994

Senior Member
Joined
Sep 21, 2013
Posts
5,063
Reaction score
5,064
Location
Florida
Ram Year
2017
Engine
Hemi 5.7
Yea. I’ve been super busy and have to send out my thermostat to caulk so he can build a plug. Heck. I’m still under warranty. Bought the truck December 2016 and only have 35,000 miles. Got a 6 year 60,000 mile warranty. Honestly the heat exchanger removal is a pita but worth it for me.
 

caulk04

Senior Member
Supporting Vendor
Joined
Mar 24, 2013
Posts
1,099
Reaction score
2,428
Ram Year
2018
Engine
5.7 Hemi
I've done a little looking at this type of thermal actuator (wxa motor), which is exactly like what's in a normal cooling system thermostat and I'm not finding any off the shelf products. It'd be great if there was and we could just get a lower degree version but it seems like you have to go through a manufacturer and get something built to order.

Either way, I'm still going to make a dummy thermostat. It'll be a quick swap in just like the revmax kit describes for installing just the brass plug.
 

Nick14

Senior Member
Joined
Oct 19, 2019
Posts
172
Reaction score
131
Location
Knoxville, TN
Ram Year
2014
Engine
3.6
First off, EXCEPTIONAL JOB!! My hat is off to you fellas. Thirty years ago, I would be right in the middle of this. I am watching this closely. I am going to change fluid/filter this summer and would like to do something about these temps. My goal is to just make the system like the old days, trans cooled by the rad. I am going to install a 190F thermostat and if I can, I would like my trans to maintain the same temp. There is a ton of info I am trying to absorb from this post. Nick
 

Different Drummer

Senior Member
Joined
Oct 20, 2020
Posts
612
Reaction score
664
Location
North East
Ram Year
2017
Engine
Pentastar V6
You are right. You remove the thermostat and the bulk of the fluid still wants to flow through the heater instead of the cooler. That is why I am looking to at least partially plug the hole to the heater so it will flow to the cooler.


Sent from my iPhone using Tapatalk
Sounds like a plan for those who need or want to keep things incognito.
Looks like a difficult area to get to. I am curious as to how you plan to restrict or close the opening. I keep returning to the idea of interrupting the coolant flow from the cooling system into the heat exchanger. If the Temperature difference in the heat exchanger is such that there is no heating effect then just let the transmission fluid flow through it.
1) Transmission fluid passes through the cooler in front of the radiator
2) Returns to the Transmission thermal control unit mounted on the Tranny
3) With the spring loaded valve removed some of the fluid goes to the Transmission and some goes through the heat exchanger Thats what I have gathered from reading this thread, am I wrong?
4) Transmission fluid that enters the heat exchanger does not pick up any heat because there is no heat there to pick up as a result of blocking ( or possibly diverting )the radiator coolant flow into the transmission thermal management unit. Mission accomplished without getting into removing and modifying things.

Now, having said all that, I have not even been close to examining one of the thermal management units. Wild one and Crazykid1994 have been into the unit with hands on and close up experience. Either might be able to deflate my theory. For what you want to do it seems like a fairly non invasive way to go that is easily reversible.
 
Last edited:

crazykid1994

Senior Member
Joined
Sep 21, 2013
Posts
5,063
Reaction score
5,064
Location
Florida
Ram Year
2017
Engine
Hemi 5.7
If you had the thermal management unit it would be super easy to create a piece similar to the thermostat that would just fit into the plastic cap, same as the thermostat, and reach far enough in to cover the rear hole. I think the factory thermostat just causes a restriction to the rear hole as there is no way for it to fully block it off by what I saw when I had it apart. You would need a thermal unit to make measurements though. A measured restrictor could actually work to keep the heater side functional to keep temps up but still allow more fluid through the radiator if that’s what was wanted. That’s actually why I’m sending caulk my thermostat. He is planning on creating a restrictor based off of the design of the thermostat in the fully open position.
 
OP
OP
W

Wild one

Senior Member
Joined
Jan 17, 2016
Posts
23,826
Reaction score
54,856
Ram Year
14 Sport
Engine
5.7
I'd be a little gunshy on trying to restrict the bypass ,but still have enough flow to the cooler to handle a high heat situation,like say you were towing,and hit a long hill.The tranny pump doesn't have alot of gpm flow capacity from what i can tell,and if you have a controlled leak through the bypass that works while under light load,that controlled leak might bite you in the ass,when the transmission has to start working harder,and the pump might not have enough volumne to feed both the bypass,while still sending enough fluid through the cooler to keep heat under control.It'd be a fine line on a replacement plug that allows a controlled leak to feed both the bypass and the cooler,especially once the fluid starts getting thinner as it gets hotter.The thinner the fluid,the more fluid that'll be fed through the bypass,and won't make it to the cooler. Honestly after looking things over and seeing how the fluid is routed through the unit,i think removing the thermostat and installing the plate is probably the best solution. It's also very easy to reverse if you have to return things back to stock for a warrenty claim.That's just my opinion though,lol.
 

crazykid1994

Senior Member
Joined
Sep 21, 2013
Posts
5,063
Reaction score
5,064
Location
Florida
Ram Year
2017
Engine
Hemi 5.7
I'd be a little gunshy on trying to restrict the bypass ,but still have enough flow to the cooler to handle a high heat situation,like say you were towing,and hit a long hill.The tranny pump doesn't have alot of gpm flow capacity from what i can tell,and if you have a controlled leak through the bypass that works while under light load,that controlled leak might bite you in the ass,when the transmission has to start working harder,and the pump might not have enough volumne to feed both the bypass,while still sending enough fluid through the cooler to keep heat under control.It'd be a fine line on a replacement plug that allows a controlled leak to feed both the bypass and the cooler,especially once the fluid starts getting thinner as it gets hotter.The thinner the fluid,the more fluid that'll be fed through the bypass,and won't make it to the cooler. Honestly after looking things over and seeing how the fluid is routed through the unit,i think removing the thermostat and installing the plate is probably the best solution. It's also very easy to reverse if you have to return things back to stock for a warrenty claim.That's just my opinion though,lol.
I agree with you 100% on that. Hence why I fully deleted the heater. My truck gets used for hauling and off-roading which is hell on the temps. My trans would get over 200° while off-roading which goes to show the factory thermostat is just a controlled restrictor. It does not shut the heater off completely.
 

Latest posts

Members online

Forum statistics

Threads
211,282
Posts
3,064,503
Members
171,565
Latest member
Bettula
Back
Top