Trans coolers

[BAKNBLK]

I'm looking at 2 different ones, the CSF, #8344 34% Larger Core Volume and 68% more Fluid Volume and the Mishimoto, MMTC-JL-18SL 93% increase in external tube area and 32% overall fin area .

The info they provide doesn't allow comparison so who knows witch one will provide the most cooling.

Anyone install one and has temp drops?

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[Willys41]

I'm looking at 2 different ones, the CSF, #8344 34% Larger Core Volume and 68% more Fluid Volume and the Mishimoto, MMTC-JL-18SL 93% increase in external tube area and 32% overall fin area .

The info they provide doesn't allow comparison so who knows witch one will provide the most cooling.

Anyone install one and has temp drops?

If you want to keep all temps down, coolant, oil and trans install a RPM Extreme JL fan controller.
You will be amazed at how well it works keeping all temps down.
I have been running one for 3 years now and my coolant and oil temps are down by 25 to 30 degrees.
Your jeep has a transmission heater so you will always see temps about the same as the coolant.


A Mopar transmission heater (also known as a transmission warmer or heat exchanger) works as an oil-to-water thermal regulator. It circulates hot engine coolant through a series of passages directly adjacent to the transmission fluid to maintain optimal fluid temperature and viscosity.

How It Operates

• Cold Starts & Warm-Up: When the engine is started in cold weather, the transmission fluid is thick, which causes sluggish shifting and increased wear. The heater uses the rapidly heating engine coolant to quickly warm the transmission fluid to its ideal operating temperature. [1, 2, 3, 4, 5]
• Thermal Bypass Valve (TBV): A built-in thermostat controls the flow. It directs transmission fluid through the heater until it reaches roughly 180°F (82°C). Once the fluid reaches this threshold, the TBV routes the fluid to the external transmission cooler to prevent overheating. [1, 2]
• Cooling Mode: If the transmission works hard and exceeds engine coolant temperatures, the heat exchanger works in reverse, allowing the cooler engine coolant to absorb excess heat from the transmission fluid to prevent it from overheating. [1, 2]

If you are experiencing issues with your transmission heater—such as a coolant leak, a check engine light, or harsh shifting in the cold—provide the model and year of your vehicle to help determine if the thermostat or heat exchanger needs to be

https://store.mopar.com/oem-parts/m...0PdLuwF91hQpZ3xquKYmrhPzDGXe8hj4aAgm5EALw_wcB

http://www.rpmextreme.com/Product/311/Jeep-JL-JT-PWM-FAN-CONTROLLER-.aspx

 

[BAKNBLK]

Ya I know all that... Tazer works just fine and I will never buy anything from RPM.

 

[azjl#3]

So I run hwy 87 PHX to Payson every week all year, currently 102f, 7% climbs AC on, 65-70mph, 35's on 4.1, I never see over 200 on tranny. Using 10w30, I never see over 220 on coolant, oil goes to coolant temp unless i Use 5th last mile, then creeps to 230, cools as soon as i hit summit.

 

[croppz]

Ya I know all that... Tazer works just fine and I will never buy anything from RPM.

May I ask why? Just curious

 

[BAKNBLK]

have my reasons

 

[zouch]

curious; why? that's something i've rarely seen reported here as a problem.

are you seeing unacceptable trans temps? and what are you doing when you see them?

I'm looking at 2 different ones, the CSF, #8344 34% Larger Core Volume and 68% more Fluid Volume and the Mishimoto, MMTC-JL-18SL 93% increase in external tube area and 32% overall fin area .

The info they provide doesn't allow comparison so who knows witch one will provide the most cooling.

Anyone install one and has temp drops?

 

[BAKNBLK]

I want my trans temps below 200* if possible. I live at 5000' weigh over 7k lbs and have 6*+ grades everywhere. Summers are high 90's+

 

[Willys41]

The normal operating transmission temperature for a 2020 Jeep Wrangler ranges between 175°F and 225°F. During normal driving conditions, your temperature will typically hover between 180°F and 210°F.

Temperature Ranges at a Glance

• Ideal: 175°F to 200°F
• Normal Operating: 180°F to 225°F
• Heavy Load/Towing: 215°F to 235°F is acceptable, though it should be monitored closely.
• Warning Zone: Above 230°F to 240°F
• Danger Zone: Above 240°F to 250°F (Fluid begins to break down, varnish forms,

 

[BAKNBLK]

again

 

[croppz]

again

I mean if you’re just gonna be a smartass just figure it out for yourself?

 

[BAKNBLK]

didn't mean to get your panties upset.

 

[tobyw]

I don't have a dog in the fight here, but the provided data is from 1999, so it's pushing 30-years old... Fluids and the materials they are made to protect (bearings, seals, clutch materials, etc) have evolved pretty significantly since then, so I'm not entirely sure how valid that information is anymore? It's good guideline info I suppose, but I wouldn't loose any sleep about exceeding any of those ranges these days... Just my $0.02, worth exactly what you paid for it.

 

[ASSFROW]

didn't mean to get your panties upset.

 

[BAKNBLK]

I don't have a dog in the fight here, but the provided data is from 1999, so it's pushing 30-years old... Fluids and the materials they are made to protect (bearings, seals, clutch materials, etc) have evolved pretty significantly since then, so I'm not entirely sure how valid that information is anymore? It's good guideline info I suppose, but I wouldn't loose any sleep about exceeding any of those ranges these days... Just my $0.02, worth exactly what you paid for it.

Yes Fluids have got better but as late as 2022 ZF notes that for every $20°F ($11.1°C) increase in operating temperature above 175°F (79.4°C), the life expectancy of automatic transmission fluid is cut in half

Seals and clutch materials I would think is the reason that ZF and others want cooler temps.

So that's why I want to keep the fluid cool, others can do what they fell best.

I just wanted opinions on the 2 coolers I listed.

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