Transmission Cooler

[dvc357]

Brothers!
I have a 2018 Ram 2500 Power Wagon. It has the 6spd, I believe 66RFE. I’m going to be doing some towing with it and want to add a transmission cooler. Anyone have any experience or reviews on coolers? Any recommendations would be appreciated.

 

[crash68]

There should already be a transmission cooler on the truck. People do swap in a transmission thermal bypass block to lower the transmission temps.

 

[jvbuttex]

People do swap in a transmission thermal bypass block to lower the transmission temps.

I thought the reason for the bypass is to not use the thermostat in the block which routes the fluid back to trans for quicker warm ups. If you are driving down the road for lets say 30 min, thermo opens and fluid goes to the cooler.

 

[crash68]

I thought the reason for the bypass is to not use the thermostat in the block which routes the fluid back to trans for quicker warm ups. If you are driving down the road for lets say 30 min, thermo opens and fluid goes to the cooler.

The factory transmission thermostat has been known to fail, the bypass block eliminates that thermostatic element that forces the fluid back into the transmission.
Unless your in an extreme cold climate, a low RFE transmission fluid temperature isn't really a problem.

68RFE / AS69 ZeroStat Transmission Cooler Thermostatic Bypass 2013 – 2018 ZeroStat Patented Technology - Revmax Converters

The best in the business

revmaxconverters.com

 

[jvbuttex]

Yes I know it can fail. I don't see how this block will decrease temps? is there a line size reduction causing lower flow?
I don't see why they need this. its not emission related.

 

[dvc357]

Brothers
I’m aware that there is a stock transmission cooler on the truck. I was looking to mount a larger supplemental cooler. Anyone have experience with this?

 

[crash68]

I was looking to mount a larger supplemental cooler.

Why? Your PowerWagon is a reduced capacity 2500, basically on par with a 1500 in the terms of towing capacity. It's not the powertrain that de-rates the towing capacity but the suspension. The factory transmission cooler has plenty of capacity for a +10K lbs trailer but in stock suspension form your trucks not going there. Also it does no good to go with a larger transmission cooler unless you remove the factory thermostat.
Instal the bypass block linked above and tow till your hearts content. If you really wanted to make a good upgrade for towing that would be to a 8HP75LT transmission (8spd found in the +19 HD trucks).

 

[crash68]

I don't see how this block will decrease temps? is there a line size reduction causing lower flow?

I see someone didn't bother to read the product description in the provided link.

 

[2003F350]

Yes I know it can fail. I don't see how this block will decrease temps? is there a line size reduction causing lower flow?
I don't see why they need this. its not emission related.

It's not a block so much as a bypass.

In a stock truck, RAM uses this transmission thermostat to bring the transmission temperature up to what they consider 'operating temperature' quicker, then keep them in a specific range to get more consistent shifts, thus making your 'average consumer' happier with their vehicle's overall performance.

HOWEVER, higher transmission temperatures are NOT GOOD for towing. You want them as low as possible to prevent slippage, since you're going to be adding a LOT of heat with the added stress of towing.

So if you bypass this thermostat, your transmission temps will go down, especially when towing, because the transmission cooler can actually do what it was designed to do - get heat out of your transmission.

 

[2003F350]

Brothers
I’m aware that there is a stock transmission cooler on the truck. I was looking to mount a larger supplemental cooler. Anyone have experience with this?

You already have a massive transmission cooler, as crash mentioned. The only reason the Power Wagon has a de-rate in towing and payload capacities is the softer suspension - the rest of the truck is still a 2500, so your frame, body, transmission, engine, axles, cooling system, etc, is basically identical to a regular 2500 that comes with a 10k+ GVWR and a MUCH higher trailer tow rating.

I had a 2017 Wagon (I gotta update my signature), and towed a 35' ultralite camper with it, GVWR of about 8500 I think? Not really that heavy for such a long camper. Never had any issues with temps, even WITH the thermostat operating properly. Never really had any issues with more weight than that either (towed a 42' park model camper too), aside from sway, mostly because that suspension didn't fight sway very well.

I've now got a '22 CTD 2500, and I didn't even bother with the WDH bars or sway control the last few times I moved the camper from storage to my house. No issues with sway at 55mph, but at higher speeds I'd still recommend the sway control.

 

[dvc357]

So, I’m hearing that for towing, (8500# travel trailer. Yes, the first thing I did was add a set of Timberline air bags and onboard compressor. So, No sag or sway) No one adds a supplemental cooler. I did read the link about the bypass. It seems that just keeps the thermostat open at all time but it doesn’t actually allow more cooling. It gives full cooling immediately.

 

[2003F350]

So, I’m hearing that for towing, (8500# travel trailer. Yes, the first thing I did was add a set of Timberline air bags and onboard compressor. So, No sag or sway) No one adds a supplemental cooler. I did read the link about the bypass. It seems that just keeps the thermostat open at all time but it doesn’t actually allow more cooling. It gives full cooling immediately.

I'm going to make some assumptions here.

For an 8500 lb bumper-pull travel trailer with a properly set-up WDH, you won't need the air bags. It will squat your truck about 3/4" with the WDH set up. They're a waste of money for your rig. A WDH system is cheaper and faster than a fancy system like you've installed. Sure, with air bags you might look like you have no 'sag' or 'squat' but your front axle is still unloaded somewhat, so your steering is compromised.

With properly adjusted sway control, you won't have sway. Air bags don't really help with sway anyway.

No, no one adds a supplemental cooler when towing with a Power Wagon if they're staying inside specs. There's no need for one.

To me, I think you're trying to say you're wanting to pull this camper on just a hitch ball with no WDH or sway control - and that's just a dumb idea. I wouldn't want to be anywhere near you on the road, because you're not towing safely. You may not have a problem, but you're sure asking for one. For less than $500 you can buy and set-up a budget WDH and sway control and be safe.

It sounds like you're pulling a camper similar in size and weight to what I have. My '17 Wagon was ALL STOCK (no bypass, stock size tires, stock suspension, no air bags or other add-ons), I had my WDH set up properly and used a stand-alone sway control system, and had NO sway at 65 mph on the expressway (unless it was windy out). I had no issues with temperatures even after pulling big hills on a 4 hour trip north.

What I am saying is, get your WDH set up right, use a sway control, don't try to pull at 70+ mph the entire time, and you'll be absolutely fine.

 

[crash68]

 

[crash68]

So, I’m hearing that for towing, (8500# travel trailer. Yes, the first thing I did was add a set of Timberline air bags and onboard compressor. So, No sag or sway) No one adds a supplemental cooler. I did read the link about the bypass. It seems that just keeps the thermostat open at all time but it doesn’t actually allow more cooling. It gives full cooling immediately.

That's correct, the transmission cooler is plenty big for what a full rated 2500 can tow so your good there.
As mentioned your going to want a WDH, and not rely on the airbags as much. It's been a while since this video has been posted. It shows you the difference between a WDH and airbags do: https://youtu.be/XBZu39pQ8Gg

 

[dvc357]

Good video,
I wasn’t planning on going without a weight distribution hitch. I already have air bags and a WDH. I was trying to find out individuals experiences with a trans cooler. I get that it’s un needed.

 

[CVORider59]

Opt for the larger billet tranny pan! Adds almost 3 quarts to your total fluid capacity and runs cooler with the cooling fins on the pan. Do change out your pump/shift body if you have the notorious 68 tranny. You will prevent a massive failure in the tranny if you change it out now! I went with a Shift Master billet valve body, oversized servo and metal pistons with the two added screws in the piston back plate, plate is failure point.

 

[JOHN WISE]

To reply to your original question. I added a plate style cooler with a thermostically controlled fan to my 2001 7.3 Powerstroke and got 262,000 miles out of the original transmission.

I did a lot of heavy towing too.

Here in Texas you can never get trans fluid too cool.

Cost was about $350 if I remember.

 

[Andrei20]

It's not a block so much as a bypass.

In a stock truck, RAM uses this transmission thermostat to bring the transmission temperature up to what they consider 'operating temperature' quicker, then keep them in a specific range to get more consistent shifts, thus making your 'average consumer' happier with their vehicle's overall performance.

HOWEVER, higher transmission temperatures are NOT GOOD for towing. You want them as low as possible to prevent slippage, since you're going to be adding a LOT of heat with the added stress of towing.

So if you bypass this thermostat, your transmission temps will go down, especially when towing, because the transmission cooler can actually do what it was designed to do - get heat out of your transmission.

My temperatures while towing a 6000lbs travel trailer. The transmission temperature is the same as going empty. Transmission is AS69. Engine is Cummins 6.7. The only thing that changed compared to running empty is the engine oil temp, usually it sits at 94 Degrees Celsius.

 

[2003F350]

My temperatures while towing a 6000lbs travel trailer. The transmission temperature is the same as going empty. Transmission is AS69. Engine is Cummins 6.7. The only thing that changed compared to running empty is the engine oil temp, usually it sits at 94 Degrees Celsius.

That's pretty much normal, mostly because of the transmission thermostat. It's pretty good at keeping the transmission temp in a particular range, so long as your engine cooling system is working properly.

However, if it starts to act up (which it is prone to), your transmission temps can get out of hand. I think THAT'S more the problem people are trying to head off.

 

[NicksGarage]

I have a 2009 1500 4x4 and when towing in slow moving traffic when it's hot out, the transmission heats up, at times going into limp-in mode. The last time was towing my 3000 pound travel trailer in stop-n-go traffic. This truck has the transmission cooler integrated into the A/C condenser. It does not have the bypass block of the later models. I haven't been able to find out what the transmission cooler is like in the towing package or if there is a difference. Doesn't look like the transmission fluid goes through the radiator at all. I'm going to try an aftermarket cooler with a fan to see if that solves my problem.