42RLE external cooler

[AdventurePig]

Good morning,
Rebooting this conversation.

Currently our aux fan/cooler runs ALL the way back to our rear tire carrier via some super long tranny hoses.

Our rig’s auto tranny is in good shape and we’ve had it serviced since we’ve owned it, so i hate to mess with what works but our goal is to lighten this rig wherever possible and we don’t plan on keeping our swingout for several reasons.

To that end, I want to ask your-allz thoughts how best to relocate/redesign our external cooler/fan setup.

Some options include:

1. Undercarriage Derale mount near tcase - problem is, we don't have any space there because of out longarm/3link setup.

2. Mount in front of radiator - in this position do we need a fan mounted? Or would the existing radiator electric fan rigged to turn on at +\- 200° do the job?

3. Other locations with a smaller/alternate design cooler?

 

[AdventurePig]

Also, based on the connections pictured, would i be able to simply gently pinch off the hoses to stop the flow, or are these under quite a bit of pressure? (Meaning, i’d probably want a pro to handle this.)

 

[tworley]

Not how I would run a trans cooler...

Many of the 42RLE owners here use a Setrab cooler mounted to the vbar in front of the radiator.

 

[hear]

I have my Hayden mounted in front of my radiator, no aux fan. I've never seen it get over 165F. I guess it all depends on the conditions and workload, but I can't see any reason to mount it anywhere else. Underneath just seems like it's begging to get dragged over rocks.

 

[AdventurePig]

Not how I would run a trans cooler...

Many of the 42RLE owners here use a Setrab cooler mounted to the vbar in front of the radiator.

Yeah..…there are lots of strange mods on this rig that we’re slowly undoing for a “restomod” or “superstock” type build.

Thanks for the reference. I’ll do a search on that setup.

 

[Apparition]

I'm replacing my Derale with a Setrab, tired of hearing the stupid fan. See this thread for direction.

https://wranglertjforum.com/threads...eference-pictures-to-aid-some-installs.77365/

 

[mrblaine]

Good morning,
Rebooting this conversation.

Currently our aux fan/cooler runs ALL the way back to our rear tire carrier via some super long tranny hoses.

Our rig’s auto tranny is in good shape and we’ve had it serviced since we’ve owned it, so i hate to mess with what works but our goal is to lighten this rig wherever possible and we don’t plan on keeping our swingout for several reasons.

To that end, I want to ask your-allz thoughts how best to relocate/redesign our external cooler/fan setup.

Some options include:

1. Undercarriage Derale mount near tcase - problem is, we don't have any space there because of out longarm/3link setup.

2. Mount in front of radiator - in this position do we need a fan mounted? Or would the existing radiator electric fan rigged to turn on at +\- 200° do the job?

3. Other locations with a smaller/alternate design cooler?

View attachment 594030

If we don't know which trans we are dealing with, then we get the answer for a 32 which can be cooled by a wet sponge in front of the grill and we miss the NEEDS all the help it can get for the 42RLE here in SoCal. Which trans are we dealing with? Where is the temp gauge sender installed?

 

[mrblaine]

I have my Hayden mounted in front of my radiator, no aux fan. I've never seen it get over 165F. I guess it all depends on the conditions and workload, but I can't see any reason to mount it anywhere else. Underneath just seems like it's begging to get dragged over rocks.

You know, you're a smart guy so I don't know why we keep having to do this. The 32RH has almost nothing in common with the 42RLE. Make the distinction so you don't send someone down a path of dumbness.

 

[AdventurePig]

If we don't know which trans we are dealing with, then we get the answer for a 32 which can be cooled by a wet sponge in front of the grill and we miss the NEEDS all the help it can get for the 42RLE here in SoCal. Which trans are we dealing with? Where is the temp gauge sender installed?

Type: It’s a 2004 42RLE.

Temp gauge: i have no idea. but i can recon and report back.

 

[LONGJP2]

3. Other locations with a smaller/alternate design cooler?

I moved my Derale cooler to the rear of the tub (underneath).
I'm guessing my LJ might have more space there.

 

[hear]

You know, you're a smart guy so I don't know why we keep having to do this. The 32RH has almost nothing in common with the 42RLE. Make the distinction so you don't send someone down a path of dumbness.

Yeah, I see now in the subject line it says 42RLE. But 18 minutes after my idiotic, misleading, and unhelpful post, you asked for clarification on which transmission was in play here, so I'm not sure you treating me like an idiot is warranted in this case.

 

[AdventurePig]

Ok, here’s some pics of the current setup. I’m assuming temp sensor is one of those aluminum/brass blocks on the lower “hot” side going to the passenger side port in the radiator?
(Not sure why there are two? ) and then it looks like the driver side port goes back to the remote cooler, through the cooler and then plugs into the upper hard line (cool) return.

Edit: you know, i think one of those blocks is probably for the in-cab temp sensor and one of them is for the electric fan. Maybe?

 

[AdventurePig]

Some things i think i know :

1. I want the temp sender in the tranny pan not the hot “out” line for the most accurate read, correct?

2. Routing would be:

• tranny hot hard line to radiator inlet(passenger side). (Maybe it’d be good to go back to a stock hose for this?)
• radiator outlet to new grill mounted cooler
• New cooler to cool upper hard line into tranny

3. The connections i see are leaking a bit. Can i do better with different types mentioned here in Blaine’s writeup?:

“This is the push on method with 2 Oetiker clamps. The other method is to cut the factory barbed end off and use a compression to -6 male. They are about 15 bucks each in steel so we tend to lean more towards using the clamps.”

 

[1904-06LJR]

The leaky red fluid indicates that is likely your temp sender. It's in the wrong spot for an accurate trans temp reading. Most on here will tell you it needs to be mounted on the front side of the transmission oil pan. Dorman makes an aftermarket one for the 42 with the bung already pressed in it. It's about 50/50 of them leaking. I actually had really good luck with the drill and sandwich type fitting from Russel's I believe. I made sure I cleaned the burrs on each side and used some high temp gasket maker as kind of a "thread locker" and so far, I have no leaks. It's something I watch though. I can't say enough about how happy I am with spending the extra coin to go with a Setrab mounted to the V-bar. I rarely see trans temps on my 42RLE getting above 200 on really hot days while slow crawling. I highly recommend this route.

This is your aux cooler routing:

 

[psrivats]

The leaky red fluid indicates that is likely your temp sender. It's in the wrong spot for an accurate trans temp reading. Most on here will tell you it needs to be mounted on the front side of the transmission oil pan. Dorman makes an aftermarket one for the 42 with the bung already pressed in it. It's about 50/50 of them leaking. I actually had really good luck with the drill and sandwich type fitting from Russel's I believe. I made sure I cleaned the burrs on each side and used some high temp gasket maker as kind of a "thread locker" and so far, I have no leaks. It's something I watch though. I can't say enough about how happy I am with spending the extra coin to go with a Setrab mounted to the V-bar. I rarely see trans temps on my 42RLE getting above 200 on really hot days while slow crawling. I highly recommend this route.

This is your aux cooler routing:

View attachment 594880

Blaine has the Dorman 42RLE trans pan with a bung for the sender already brazed and entire thing is properly powdercoated. There will be no leaks because Blaine knows what he is doing This pan (thicker than OEM), a good cooler and a temp gauge are must have for every TJ 42RLE owner imo.

https://blackmagicbrakes.com/ols/products/42rle-transmission-pan