Trans thermostat - JeepForum.com
 
LinkBack Thread Tools
post #1 of 10 Old 10-21-2021, 08:42 PM Thread Starter
Liebo
Registered User
1998 ZJ 
 
Join Date: Feb 2020
Location: Metro Detroit
Posts: 27
Trans thermostat

Hey all,
Sort of a think piece here about a possible retro fit.
Recently I was changing oil on a 2016 Cherokee 3.2 v6. I happen to notice what appeared to be a mechanical thermostat, as part of the trans cooler, or at least hard lined into the trans cooler.

Im wondering if anyone has tried this yet. Im posting this and realizing I dont have pictures, and havent looked at prices yet. But this seems at-a-glance to be a pretty decent idea for my 5.9 when the trans work happens.

Of course providing they operate on the same temp range/ pressure. Where would that info be? Reliably.

Just an idea, thanks.

Liebo is offline  
Sponsored Links
Advertisement
 
post #2 of 10 Old 10-22-2021, 12:04 AM
ravenworks
Registered User
 
ravenworks's Avatar
2006 LJ Wrangler 
 
Join Date: Jul 2012
Location: NE
Posts: 5,877
You can buy it as a replacement and splice it in.
I'm not on a computer or I'd give you a link.

Semper-Fi "81-84"
I.U.O.E. - 18
ravenworks is offline  
post #3 of 10 Old 10-22-2021, 08:39 AM
zjosh93
Registered User
1993 ZJ 
 
Join Date: Aug 2010
Location: Austin
Posts: 3,352
I'm pretty sure Timo has one on his. Good idea for very cold climates. There are plenty of aftermarket options.
zjosh93 is offline  
 
post #4 of 10 Old 10-22-2021, 09:15 AM
kg6mov
Hears the voices
 
kg6mov's Avatar
1996 ZJ 
 
Join Date: Nov 2012
Location: Cupertino
Posts: 16,522
Yup, if you’re at risk of over cooling the transmission (like Timo) it’s a really good idea.

His setup is here: https://www.jeepforum.com/forum/f197...l#post35209193


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

1984 F250, 460 BB, T19, work truck/future tow pig
1987 Mercedes 300D Turbo, the diesel daily, 30mpg in style

Quote:
Originally Posted by Texas ZJ1 View Post
I heard someone yell "mall crawler" from the back porch. I'll go see who said that. Be right back.
kg6mov is offline  
post #5 of 10 Old 10-22-2021, 09:49 AM Thread Starter
Liebo
Registered User
1998 ZJ 
 
Join Date: Feb 2020
Location: Metro Detroit
Posts: 27
Im in Michigan so the only reason it doesnt have one yet is because of over cooling. Thanks everyone!
Liebo is offline  
post #6 of 10 Old 10-22-2021, 12:02 PM
Timo_90xj
Web Wheeler
 
Timo_90xj's Avatar
1998 ZJ 
 
Join Date: Mar 2006
Location: Helsinki, Finland - on the European side of the Atlantic
Posts: 11,203
Yeap, in cold weather an inline t'stat is a really good idea. kg6mov already linked to my build thread, there might be couple of pictures missing. Anyways, after I installed the in-line t'stat to transmission cooling setup, transmission temps have been much more consistent and it reaches operating temp much quicker in cold weather.
Transmission also stays warm enough during cold days, which it did not before the t'stat and auxiliary cooler. Under heavier use - wheeling, towing, stop-and-go-traffic - in warm summer days (here it means 75-85F ), pan temp has never gone above 190-195F and mostly stays between 165-175F.


Here in southern Finland winters aren't actually that cold considering Helsinki is pretty much at the same latitude as Anchorage - Jan./Feb. daily mean is around 20...25F, and usually only total of 2-3 weeks of when temps get down to -20...-30F. Up in northern Finland winters are more like the northern Midwest states in the USA - plenty of snow and cold days down to -40 and occasionally lower.




1998 Grand Cherokee 5.9 LX daily driver, 1.75" BB, 32" KM2s, HPD30 Eaton e-locker/D44a stock LSD, 4.56 gears, custom- fabbed tube bumpers and tube fenders,...


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



1990 XJ Limited (4-door), 4.0 I6, AW4, NP242, ***rolled and totalled @ 165k miles***

***Under construction***
1990 XJ (4-door), 4.0 I6, AW4, NP242, PBR 42" tires, Unimog 404 portal axles, 110" WB, full cage + uniframe completely rebuilt, front 3-link + panhard / double triangulated 4-link rear,... ***SOLD***
Timo_90xj is offline  
post #7 of 10 Old 10-22-2021, 06:01 PM
PolkaPower
Registered User
 
PolkaPower's Avatar
1998 ZJ 
 
Join Date: Aug 2011
Location: The Abyss
Posts: 23,776
Google search "oil thermostat". There's a variety to choose from.


Sent from my iPhone using Tapatalk
PolkaPower is offline  
post #8 of 10 Old 10-23-2021, 08:53 AM
jeepjeepster
Registered User
 
Join Date: Dec 2004
Posts: 4,027
Dang, that is a beautiful setup. Those braided lines and AN fittings look fantastic.

Idk what the reliability is of the thermostat, but I would worry its just something else that could go bad (I dont mean to sound like an old man here). Alot of Jeeps came with those from the factory though. First time I saw one was on a Commander, I think the WK's got them too.

I will say, my liberty with the factory AUX only cooler wont get above 100F on cold days. I added a finned aluminium pan this summer so I imagine it will be even colder now.

1994 ZJ-I6 w/270,000 mi
1998 ZJ 5.9 w/66,000 mi Slate Black
2004 KJ w/108,000 mi
jeepjeepster is offline  
post #9 of 10 Old 10-23-2021, 09:43 AM
PolkaPower
Registered User
 
PolkaPower's Avatar
1998 ZJ 
 
Join Date: Aug 2011
Location: The Abyss
Posts: 23,776
I don't see the problem. The risk /reward ratio checks out. The reason you would use this is because you bypass the radiator which is a catastrophic failure for the transmission if the coolant line breaks inside. It doesn't happen often but more than you think.
Separate the engine runs a tad cooler and so does the transmission. You can keep an eye on either temps with guages. There's already a tstat in the engine housing and we accept that risk. Imo it's better to have the transmission and engine separate and you only need to worry about running the transmission too cool in cold climates.


Sent from my iPhone using Tapatalk
PolkaPower is offline  
post #10 of 10 Old 10-23-2021, 11:57 AM
Timo_90xj
Web Wheeler
 
Timo_90xj's Avatar
1998 ZJ 
 
Join Date: Mar 2006
Location: Helsinki, Finland - on the European side of the Atlantic
Posts: 11,203
I've had the radiator loop in my transmission cooling setup, but I will bypass it once I get a larger auxiliary cooler and my other upgrades done.
I was initially a bit worried about not having the transmission stay at operating temp in cold weather with the aux cooler, but it turned out to be a non-issue with the t'stat. I've just been postponing making the mod because everything has been working perfectly. Now that I have the engine and transmission out for upgrades, I have no excuses to not do anything about it

As for the t'stat, most of them which are built to be used for lubrication/ hydraulic systems have a built- in bypass that allows about 10-15% of the fluid to flow straight from feed to return line.

1998 Grand Cherokee 5.9 LX daily driver, 1.75" BB, 32" KM2s, HPD30 Eaton e-locker/D44a stock LSD, 4.56 gears, custom- fabbed tube bumpers and tube fenders,...


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



1990 XJ Limited (4-door), 4.0 I6, AW4, NP242, ***rolled and totalled @ 165k miles***

***Under construction***
1990 XJ (4-door), 4.0 I6, AW4, NP242, PBR 42" tires, Unimog 404 portal axles, 110" WB, full cage + uniframe completely rebuilt, front 3-link + panhard / double triangulated 4-link rear,... ***SOLD***
Timo_90xj is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome