Re:Do Gen 4 Hemi 2500 have trans cooler stock?

Since buying a new/heavier trailer (travel/toy hauler) my quest to upgrade my Diff & transmission cooling has run into a few hurdles.
1. Apparently Banks only make their new ram-air diff covers for Diesels OR 2019 & newer gas 2500`s (different`t bolt pattern). Mine being a 2016 is not included, per my call with Banks today. Strike 1.

2. So far, deep pan trans pans are for RFE68, not my 66RFE. Yes there are stock config finned aftermarket pans but a deep pan doesn`t clear the exhaust crossover! Strike 2!

3. As a result, I thought that I would just add an aux trans cooler and a Revmax bypass instead, in searching for plug and play trans coolers it looks like they already came stock on a HD 2500!
The trans shroud covers the inside/back of the radiator, the best I could see there didn`t appear to be an external trans cooler, the cooler in front of the radiator appears to be the a/c condenser.
There is however a 2ed electric fan behind the rad in front of the engine fan. Strike 3?
DOES ANYONE KNOW HOW THESE GAS 2500s are equipped stock? Is there a aux trans cooler option? Thank you in advance for any help on my quest!

P.S. I hate that the aftermarket does not support gas models like they do with diesels....

Oh, boy - the heavy duty lineup did not follow the same model generation timing as the ilght duty models.

What I can tell you, that my 2017 MY heavy duty model DOES fit the Banks Ram Air Differential Cover. I have one installed. It fit perfectly.

I can also tell you that the 68RFE is a derived 66RFE, with certain component upgrades, the pan and trans cooler should fit, IMO. Yes, 66RFE has a trans cooler, otherwise it wouldn't have a thermostat block, right? I installed the RevMax thermostat bypass as well.

You NEED the RevMax thermostat bypass if you want your trans to live.

You NEED to change the trans oil every 3 yrs / 36k miles or so.

You NEED to use top synthetic oil in the RFE - we use Red Line C+ATF.

If you do these things, and don't lug the trans, you should be ok. Use the tow program when towing (keeps shifting rpm up), lock out in 4th gear. 5th and 6th "gear" are both overdrives.

Thank you for the advice, I appreciate it!
I guess more research is in order, I agree SOME 68RFE stuff also fits the 66RFE, very frustrating trying to sort out what also fits gas trucks and what doesn`t, everything is slanted towards the diesel folks...

Rick Ram-jet said:

Thank you for the advice, I appreciate it!
I guess more research is in order, I agree SOME 68RFE stuff also fits the 66RFE, very frustrating trying to sort out what also fits gas trucks and what doesn`t, everything is slanted towards the diesel folks...

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Oh, there's a thread on it somewhere.

Bigger OD clutch, bigger bell housing but I believe the transmission housing is identical - which means the oil pan mount is identical. Whether it hits pipes or not underneath I don't know. I didn't bother with a bigger sump. The thing has 4 gallon capacity, and as long as you don't overheat the oil, it's plenty. You don't need a big pan with fins if you get rid of that dumb, teeny thermostat in the oil cooler line.

HEMIMANN said:

Oh, boy - the heavy duty lineup did not follow the same model generation timing as the ilght duty models.

What I can tell you, that my 2017 MY heavy duty model DOES fit the Banks Ram Air Differential Cover. I have one installed. It fit perfectly.

I can also tell you that the 68RFE is a derived 66RFE, with certain component upgrades, the pan and trans cooler should fit, IMO. Yes, 66RFE has a trans cooler, otherwise it wouldn't have a thermostat block, right? I installed the RevMax thermostat bypass as well.

You NEED the RevMax thermostat bypass if you want your trans to live.

You NEED to change the trans oil every 3 yrs / 36k miles or so.

You NEED to use top synthetic oil in the RFE - we use Red Line C+ATF.

If you do these things, and don't lug the trans, you should be ok. Use the tow program when towing (keeps shifting rpm up), lock out in 4th gear. 5th and 6th "gear" are both overdrives.

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I'll provide anecdotal evidence to the contrary of pretty much everything you said - I drove my '17 for over 100k miles with ZERO transmission issues, and I never changed the fluid and I towed a camper around every summer with it. I never put in a thermostat bypass, I never changed the fluid, so whatever came in the transmission is what it had.

Is it the best automatic transmission out there? No. Are there people who just seem to have zero luck with it? Absolutely. But telling someone they NEED to do something when there are plenty of us out there who DON'T do those things and have zero issues is BS. They're things to consider, yes, but not a necessity.

2003F350 said:

I'll provide anecdotal evidence to the contrary of pretty much everything you said - I drove my '17 for over 100k miles with ZERO transmission issues, and I never changed the fluid and I towed a camper around every summer with it. I never put in a thermostat bypass, I never changed the fluid, so whatever came in the transmission is what it had.

Is it the best automatic transmission out there? No. Are there people who just seem to have zero luck with it? Absolutely. But telling someone they NEED to do something when there are plenty of us out there who DON'T do those things and have zero issues is BS. They're things to consider, yes, but not a necessity.

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I'm like you with Zero issues on my 2017 but the OP already has large tires and plans to push his truck with a larger load. Taking out an insurance policy with a few upgrade may be a good thing. We have all read enough about this transmission on ramforum to strike fear of what could happen.

Lsujker said:

I'm like you with Zero issues on my 2017 but the OP already has large tires and plans to push his truck with a larger load. Taking out an insurance policy with a few upgrade may be a good thing. We have all read enough about this transmission on ramforum to strike fear of what could happen.

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This is all very true, and I missed that OP already has larger tires. I was also running 4.10 gears, where OP might only have 3.73's or 3.55's or what have you, he doesn't say.

You're absolutely right, those things won't HURT him at all, but depending on a LOT of other factors may not do much to help either.

2003F350 said:

I'll provide anecdotal evidence to the contrary of pretty much everything you said - I drove my '17 for over 100k miles with ZERO transmission issues, and I never changed the fluid and I towed a camper around every summer with it. I never put in a thermostat bypass, I never changed the fluid, so whatever came in the transmission is what it had.

Is it the best automatic transmission out there? No. Are there people who just seem to have zero luck with it? Absolutely. But telling someone they NEED to do something when there are plenty of us out there who DON'T do those things and have zero issues is BS. They're things to consider, yes, but not a necessity.

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If you want to maximize the probability of this marginal transmission to survive, you need.to do this. Otherwise you're gambling. The effect of failure is catastrophic and mission disabling. OP asked for advice, not individual luck or difference in usage profile. That's what I provided. You have not.

HEMIMANN said:

If you want to maximize the probability of this marginal transmission to survive, you need.to do this. Otherwise you're gambling. The effect of failure is catastrophic and mission disabling. OP asked for advice, not individual luck or difference in usage profile. That's what I provided. You have not.

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And I'm telling you that they wouldn't have built it for as long as they did if it didn't meet certain criteria, one of which is something along the lines of 'will a test of XX number of transmissions reach a simulated 100k miles under its max rated conditions?' And if they didn't pass, then changes needed to be made until they did.

I worked for a company that had their own test lab for steering components, and this is 100% what we did for ANY change to the assemblies. The number of assemblies tested depended on what the change was, but it was typically 6-50. FCA does the exact same thing. And 100k miles is for the most part a common standard across the industry.

Now, yes, they are mass-produced, so there's some variation in every transmission, and SOME will fall outside that tolerance. They don't 100% inspect them, either, so some of those will make it out to the public. And THOSE are the ones you hear about - people with zero transmission issues don't complain about it, but they also don't sing its praises usually.

Also you'll note that I didn't say DON'T do the mods - they can't hurt. And I NEVER said that OP won't have issues, because yes, he most certainly could. I could have had issues - but I never did, and the vast majority of the trucks that have these transmissions never will either. I also never said that it was the best automatic transmission in the world - in fact I'm pretty sure I said it wasn't.

All I'm saying is that it is wrong to tell someone they NEED to do something - it's more appropriate to say 'this has been my experience, I recommend these things.' Saying someone NEEDS to do something on a overall stock truck because you had issues is akin to me saying that every GM 700R4 was junk because we had one when I was a kid that had to be rebuilt every 100k.

2003F350 said:

And I'm telling you that they wouldn't have built it for as long as they did if it didn't meet certain criteria, one of which is something along the lines of 'will a test of XX number of transmissions reach a simulated 100k miles under its max rated conditions?' And if they didn't pass, then changes needed to be made until they did.

I worked for a company that had their own test lab for steering components, and this is 100% what we did for ANY change to the assemblies. The number of assemblies tested depended on what the change was, but it was typically 6-50. FCA does the exact same thing. And 100k miles is for the most part a common standard across the industry.

Now, yes, they are mass-produced, so there's some variation in every transmission, and SOME will fall outside that tolerance. They don't 100% inspect them, either, so some of those will make it out to the public. And THOSE are the ones you hear about - people with zero transmission issues don't complain about it, but they also don't sing its praises usually.

Also you'll note that I didn't say DON'T do the mods - they can't hurt. And I NEVER said that OP won't have issues, because yes, he most certainly could. I could have had issues - but I never did, and the vast majority of the trucks that have these transmissions never will either. I also never said that it was the best automatic transmission in the world - in fact I'm pretty sure I said it wasn't.

All I'm saying is that it is wrong to tell someone they NEED to do something - it's more appropriate to say 'this has been my experience, I recommend these things.' Saying someone NEEDS to do something on a overall stock truck because you had issues is akin to me saying that every GM 700R4 was junk because we had one when I was a kid that had to be rebuilt every 100k.

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And I'm telling you, as a degreed engineer working for a similar corporation for decades that they cut corners to save money. And Im saying you are wrong for telling me I'm wrong for saying an OP asking for advice and me freely giving my experience.

Knock it off already.

HEMIMANN said:

And I'm telling you, as a degreed engineer working for a similar corporation for decades that they cut corners to save money. And Im saying you are wrong for telling me I'm wrong for saying an OP asking for advice and me freely giving my experience.

Knock it off already.

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I am also a degreed engineer, with a specialty in automotive powertrains - in other words I'm trained to understand these things. I'm aware that they cut corners where they can, I was involved in SEVERAL projects to do just that - it still has to meet the requirements though, and if it couldn't the project didn't continue as planned.

We can go rounds on this. I don't really want to. But you're being a bully.

You didn't give your experience, you basically told the guy 'You HAVE to do this or your transmission will explode!' I get that you have had a bad experience, and you're entitled to be able to tell people about that and what steps you took to mitigate it happening again, but to make it sound like EVERY 66RFE will explode without said steps is inappropriate, because it's not true. I'd venture to guess the failure rate is less than 1% - I don't have access to the data but if it were as serious as you make it sound there'd be a recall on it.

The reality is that he may NEVER have a problem if he leaves it stock. Is it still a good idea to do them? Sure, and I'd never tell someone NOT to do them. But does he NEED to? Not necessarily.

2003F350 said:

I am also a degreed engineer, with a specialty in automotive powertrains - in other words I'm trained to understand these things. I'm aware that they cut corners where they can, I was involved in SEVERAL projects to do just that - it still has to meet the requirements though, and if it couldn't the project didn't continue as planned.

We can go rounds on this. I don't really want to. But you're being a bully.

You didn't give your experience, you basically told the guy 'You HAVE to do this or your transmission will explode!' I get that you have had a bad experience, and you're entitled to be able to tell people about that and what steps you took to mitigate it happening again, but to make it sound like EVERY 66RFE will explode without said steps is inappropriate, because it's not true. I'd venture to guess the failure rate is less than 1% - I don't have access to the data but if it were as serious as you make it sound there'd be a recall on it.

The reality is that he may NEVER have a problem if he leaves it stock. Is it still a good idea to do them? Sure, and I'd never tell someone NOT to do them. But does he NEED to? Not necessarily.

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Ask yourself what his intent.was.

Does a bachelor of science degree from the college of engineering count as a degreed engineer? If so, I have one of those and want to sound smart. Going to start using it.

I usually want to make sure the upgrades are actually needed before spending the time and money on them. For the transmission cooling aspect I would verify the factory system wasn't able to keep the system within a reasonable range first. I have a 2016 2500 6.4L running 37's on stock 4.10 gears. Pulled a 26' 7k enclosed trailer for almost 1,000 miles last fall and the trans temp stayed rock solid around 175 F. That is plenty cool enough in my opinion, and running 150 F trans temps isn't going to help anything. Everybody says "cooler is better" but only to a certain extent. Yes, running 175 is better than running 225 all the time, but once it gets down under 200 the difference starts becoming very small. Biggest thing is the life of the fluid shortens when operating at higher temps.
To jump in to some of the above, I am also a degreed engineer and spent 10+ years working in the automotive testing world. This includes working specifically on Ram trucks performing powertrain endurance testing, along with numerous other companies and testing protocols. Just as stated above, manufacturers spend a lot of time and money testing components and they have to "pass" endurance testing prior to going into production......just not 1 truck running 1 transmission, but you will have dozens of the exact same configuration running multiple different tests. Yes, some transmission are better than others but they are not going to start production intentionally knowing they are using a transmission that always fails in a short period of time. It doesn't make sense financially in regards to the warranty, or in regards to customer loyalty (return customers).
The trouble with the internet is that you 20 people (well, if that many) jump on here and say the trans in their truck failed in a short distance and it's the worst thing in the world. Of course they always claim they serviced it all the time and only drove to church on Sundays........ 20 people posting on here over a period of a year or two seems like a lot of people are having issues. But you have to stop and remember that Ram sells about 500,000 trucks per year. This means there are literally millions of Ram trucks running around out there. Not take those 20 people on this board compared to the millions of trucks on the road and it is a miniscule amount that have problems. Nobody gets on here and makes a post that says "just randomly making a post to tell you I don't have any problems with my truck". You ONLY hear from those people with problems. Heck, people will only join this forum and only make a post to complain.

2003F350 said:

but to make it sound like EVERY 66RFE will explode without said steps is inappropriate, because it's not true. I'd venture to guess the failure rate is less than 1% - I don't have access to the data but if it were as serious as you make it sound there'd be a recall on it.

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^^^ exactly
this happens way to often on automotive forums, especially amongst those stuck back in "the good ol days"

Rick Ram-jet said:

For the record, I`ll be traveling from San Diego to Big Rapids Mich to pick up my new travel/toyhauler trailer

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While your in the area, stop at the Cedar Springs Brewing company. Great food and beir! https://csbrew.com/

As for towing your new tow hauler, unless it's overweight for your truck there won't be any cooling problems with the stock components and fluids
Depending on how your truck is equipped the one thing you'll probably wish was oversized from stock will be the gas tank.

crash68 said:

While your in the area, stop at the Cedar Springs Brewing company. Great food and beir! https://csbrew.com/

As for towing your new tow hauler, unless it's overweight for your truck there won't be any cooling problems with the stock components and fluids
Depending on how your truck is equipped the one thing you'll probably wish was oversized from stock will be the gas tank.

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Thanks for the food/bev referral, might just have to treat our friends to a night out!
You just might be on to something, the new trailer will be mostly empty (7800lbs) for the trip back, other than AMSOIL and a trans thermostat by-pass maybe I don`t need the add mods at this time, just don`t want to get flatfooted far away from home...
Once we start traveling with an 860lb Harley or our 700lb golf cart I may need the mods after all... lol
P.S. Tempted to carry some extra gas in the toy-hauler gas tank, I`m sure that I`ll need it with a gasser tow vehicle!

I have the mag-hytec 45/545 pan that is +2 quarts on my 66rfe. Works great. Has a drain plug, cooling fins. I have read that aftermarket pans like these add a lot of rigidity and strength to the transmission. I am not sure if it was the pan adding the rigidity or if it was the steel threaded filter adapter, but after install I have what sounds like a little whistled at light throttle at cruising speeds. It’s nothing alarming or annoying, but definitely noticeable. I know it’s from the transmission because if I adjust the column shifter slightly it changes and/or goes away. The pan probably stiffened up some vibration from the engine or transmission and sent it into the cable or a mounting bracket for the cable. I reset and adjusted the cable a little when I first tried the solve the problem, but didn’t really change anything, didn’t really care to dive deeper. It’s been 50k miles and everything is fine.

I tried the reusable filter gasket that came with it and it was a mistake, leaks. Drained and used RTV and been awesome. I knew the reusable gasket wouldn’t work because I also tried it on an older vehicle with 5-45 years ago with the same result. Can’t beat the RTV.