Transmission Oil Temperature Too High! - What to do when towing 5er?

[HaRVey 74.5]

I wonder if you have restricted fluid flow through your factory cooler, since you say your engine temp and fan appear to be operating normally and you are doing all the right things.
When you have your trans serviced do you have them adjust the bands? I had an '06 2500 and towed over 12k lb without issues ever, but those trans are the weak link and if out of adjustment will slip and generate more heat. My bands would require adjusting every service until finally I sold it when we moved to a Class A. I miss that truck, but avoided an expensive trans & converter rebuild/replace...

[Waiter21]

I'm running the heater full blast when taking grades so I don't overheat, much to my wife's dismay, but I'm wondering if there is anything else I can do to stop this from happening in the first place?

Add a transmission cooler, something like this:

https://www.amazon.com/Hayden-Automo...dp/B000C3F3HK/

When running, select a gear and speed so the torque converter stays locked up. Slipping creates a lot of heat.

[Clomok]

On the dodges the trans cooler has a “low temperature bypass” that opens allowing fluid to bypass the cooler entirely. It can get stuck open and not allow the cooler to fully function. There also is a fluid heat exchanger on mounted on the engine block that will help maintain trans AND engine coolant temps.

Have your trans serviced (because the warning means you also overheated the fluid) and have the trans cooler bypass cleaned. This would also be a good time to install a aftermarket aluminum pan for extra capacity.

As for “overheating” the truck never actually reduced power and the whirr was the engine fan. When it goes to 100% it moves something like 21,000 CFM, and uses some engine power to spin, and you will definitely notice when it does. I wouldn’t worry about that. The Cummins will run all day long at 225*,

Deleting the emissions will also reduce temps across the board.

[clifford j]

JML, could you clarify comments you made , you've stated twice that the "OIL PRESSURE" gauge starts to climb real high when things heat up, are you sure it's 'pressure ' your referencing .

CLIFFORD

[HDGoose]

mQUOTE=jmlnarik;4877845]Thanks for the input everyone. Here are some answers to everyone's questions:

- Truck is rated to tow up to 15,600 lbs (6.7L, Turbo Diesel Auto)
- Always in tow haul mode and on top of my fluids
- Running the heater to take away heat from the engine when I know I may start running hot
- Water temp runs a little high when warning light comes on, but nothing drastic. The oil pressure gauge is the one that starts to climb pretty high (which is why I referenced that in the previous post)

So, on to what I should do now Cleaning the coolers and double checking the fan operation is going to be the first thing to do. I can hear the rad fan (whirring sound) before any warning lights come on and I hear it running while I'm driving so I believe it's fine. The whirring noise is just especially loud right before the light comes on.

I've heard about cooling pans and I'm thinking that may help as well, but do want to make sure all stock parts are working as they should first. Checked out out the TruCool - that looks pretty helpful, cheap, and easy to install, so that may help! Also, I'm running synthetic oil. May have the shop take a closer look since I'm about due for an oil change. Thanks for the comments so far everyone![/QUOTE]


What the trailer pin weight? What the truck payload weight? My 2013 RAM 2500 diesel is close to max payload when pulling my toy hauler at 11k. My trailer without my stuff weighs about 8500. Add two touring bikes, 110 gallons fresh water, 30 gallons of fuel and our stuff and it's just added 2500 pounds of weight. I usually only carry one motorcycle, so that drops the weight down 900 pounds.

[Finance]

Sounds like the truck has not been in a qualified shop for diagnostics. That truck should not require any aftermarket assistance at all, it’s quite capable and has more than adequate cooling as built.

Better to have the cause accurately identified and corrected than throw parts or band aids at it.

[Garyp4951]

If it winds up being the vicous fan clutch only use the MOPAR brand, or you will be doing it again in a year.
One way to check it is start it up cold, and turn ac on max with hood up, and shortly the fan should start coming in moving a lot of air to keep the condenser from over heating.

[rrtribble]

Add a transmission cooling radiator. If you already have one, have it checked to make sure it isn't blocked. Unless you are towing way more than your vehicle is authorized the radiator should work.

Drive safe - Richard

[Paul R. Haller]

I have a 2008 Dodge 3500 with a 68 rfe tranny to pull my 15,000 lb quad slide 5er. I live in the west where we have hard climbs from California to Colorado. I installed a Deraile 15870 cooler run with Russell 10 AN flexible pipe from the tranny lines to the cross member under the tranny where I fabricated brackets to mount the cooler. I also installed a manual fan switch as well as a glow shift tranny temp sensor in the cooler lines to automatically switch on the fan to the cooler automatically. It took a week of work to wire and plumb the system and fab up the mounts. The tranny cooler is now tucked up under the crossmember out of harms way with a duct to direct air from under the truck to the additional cooler. I also installed a double deep pan from Mag Hy Tek and now my tranny carries almost 24 quarts of tranny fluid. I Change the filters and fluid every 15000 miles of hard towing, and now rarely does the tranny get hot. Last year in Colorado near hiway 80 I had a very hard climb that I could not go fast enough to lock the converter and it was a hot day. My tranny temp gauge said 215 degrees at the top of that grade. Even that to me is too high. I prefer to keep my tranny temps under 200degrees. I like that cooler and it’s the largest cooler deraile makes and it sports an integrated cooling fan and 1/2 inch cooling tubes so as not to restrict flow. Paul R. Haller

[consolenut]

oh look up SPAL fans and get one to replace the old fan. Those fans move a ton and i mean a ton of air. The SPAL will cool it no doubt.

[jimcumminsw]

Originally Posted by jmlnarik

Hi Everyone,

I have a 2008 Dodge Ram 2500 diesel and it's been a GREAT truck. The only issue I have with it is when I tow my 10,000lb 5th wheel up substantial grades, it tends to pop on the Transmission Oil Termperature warning light. You can definitely tell it's a probelm because the engine begins to make this "whirring" noise and power decreases. When this happens, I pull over for about 30 minutes, rev the engine for a bit, then open the hood and shut the baby down until it cools off - just as it says in the manual. I'm typically back up and running just fine after that. The manual says:

"This light indicates that there is excessive transmission fluid temperature that might occur with severe usage such as trailer towing...if this light comes on, stop the vehicle and run the engine at idle or faster, with the transmission in Neutral until the light goes off."

I'm running the heater full blast when taking grades so I don't overheat, much to my wife's dismay, but I'm wondering if there is anything else I can do to stop this from happening in the first place?

Hi; I am sorry I am late to this thread but we were on a trip with the grandkids and the internet connection where we were at was very poor.

I have a 2008 Dodge Mega Cab, 2500 with the 6.7L Cummins and the 688RFE auto, 4x4, with 3:73 differentials and I am pulling a 2016 Cedar Creek 34RL trailer. My total weight combination is a little over 20,000LBS. With aftermarket tires Nitto Dura Grappler LT285/70R/17 126R, inflated to 70 PSI rear (3415LBS each) and 55PSI front. (I don't want to hear from the weight police on my set-up)

I have set my truck up to tow heavy and have added a few aftermarket attachments to provide longevity to the major components. First option I installed were a set of gauges; Boost, EGT, and transmission temp. Mounted to the A-pillar in a gage pod. The second item was a Smarty S67 set for 60Hp/120lb.-ft. TQ at the rear wheels over stock. Next I installed a Mag-Hytec Oil pan that is deeper than standard pan (adds 3 quarts of extra oil) and is AL with fins for extra cooling. Transmission temp probe is in the pan. I then have added two differential covers to the truck one front and one rear for extra oil capacity and cooling these are also AL and finned for cooling. Rear axle temps are never over 145F when towing. I am using the standard Dodge air box with a Fleetguard air filter which is good for over 500HP. I am close to 130,000 miles on my truck now.

My trans temp are never above 200F when towing up a 6 or 7% grade. In fact, when I went up and over the continental divide going through the Eisenhower Tunnel my transmission temps were 195F.

When towing up a 6 or 7% grade I am in tow/haul mode and 5th gear, never 6th gear, which I lock out. This keeps the engine RPM's up around 2000 or so and I am doing about 55MPH. The exhaust brake is also always on when towing. My heater is never on and the AC is working when it is hot out. I also have a bug shield over my coolers in the cooling package to protect them from having finned damage.

Now with that being said. I have to ask you when was the last time you had the transmission service? I service my transmission every 60,000 miles changing both internal filters and adding Amsoil transmission fluid which is a synthetic oil that is compatible to FAC specs. When was the last time the cooling system and EGR cooler were serviced? Are you using the required coolant that FAC specifies? I would also pull an oil sample and have that tested.

Another item to look for when the transmission is service is to make sure that the spin on filter is in place and not collapsed. This could lead to overheating of the transmission oil. There may be more but this is where I would start!

[jmlnarik]

Hey everyone - thanks so much for all the great insight. This is a pretty great community of people who know their rigs. After reviewing everything, doing some more research, and talking to a few people, I'm going this route - -

1) Replace transmission fluid & filter
2) Flush engine cooling system

If needed further:
3) Auxillary cooling fan
4) Larger transmission oil pan

I'd like to keep the truck in its stock state as much as possible since it was built for the jobs I'm using it for and it could be a slippery slope once I start making mods. I'm going this route, which I believe should do the trick for me. Thanks again everyone!!

[keymastr]

I would add a deep aluminum pan now since they are replacing fluid and filter and will have it off anyway. Why pay for that labor twice?

[jimcumminsw]

Originally Posted by keymastr

I would add a deep aluminum pan now since they are replacing fluid and filter and will have it off anyway. Why pay for that labor twice?

X2;