Transmission Temps and a better cooler.

[themotoviking]

So after our first weekend trip with our (new to us)2011 E450 6.8L Class C MH from Cruise America. I noticed the transmission temp hovered around the 210-220*F range. I am using a Bluetooth dongle plugged into the ODBII port going to my Tablet (or phone) and giving me temp readings real-time.

220* F is technically within safe range but its towards the hot side and I like my transmissions to run cooler. As much research as I was able to do it appears the stock cooler only dissipates around 9,000 BTUs. The unit I have coming in this week dissipates 29,500 BTUs. I have always used Tru-Cool Brand LPD Coolers in the past in off road and towing applications where the transmission is out of lock up a lot. Due to the E450 having 1/2" lines I had to get the designed for "industrial applications". This cooler is almost a direct bolt up for my MH, I just need to work a the mounting brackets a bit.

My question to you is, if you are monitoring transmission temps what are you seeing for temps? and what is your rig size and are you towing?

[Old_Crows]

Pffffttt! 220F? You are worrying too much, Friend. The coolant, oil and trans fluid temps on a working engine should be about the same as the full open temperature of the coolant thermostat. About 212-220F. Old school thinking, that.

All of those fluids and parts can survive short term transients without worry. More so with modern engineered fluids.

The coolant/trans heat exchanger serves to warm cold trans fluid and cool hot fluid. They are very effective and I'm guessing you are under estimating its capacity. Tru-Cools are excellent! Suggest following T-C's recommendation of adding your supplemental cooler after the heat exchanger & before it returns to the transmission. Don't bypass the heat exchanger. T-Cs are thermostatically controlled by the viscosity of the fluid. If you don't need the extra capacity, the fluid bypasses the cooler. And,it will cool only as much as necessary. Cooler is not better....

One usually thinks there is a need for increased cooling capacity while the transmission is under heavy load. Somewhat... But I think the real need is when you go from a heavy work load and then slow down where the engine RPM is reduced and airflow over the radiator are reduced. Like coming to a traffic jam at the end of the off ramp after steaming along on the interstate; a stop sign at the top of a hill or exit ramp. Little airflow and low RPM don't allow efficient dissipation of the built up heat. That's where the TC earns its keep by helping shed those BTUs.

The temperature/damage charts are at least 50+ years old and are, IMHO, worthless onsidering modern engineering, metalurgy, and improvements in fluids. They do sell transmission coolers.....lots of coolers. If you are concerned about fluid breakdown change it at mfg's recommended intervals and just use their recommended fluid.

Put your dongle and iPad in the glove box....drive on....

[SRockwood]

Chopperbob wrote:
My 2001 never sees anything close to that. I have a manual guage. They must have done something different in the newer models. If I we're you I would install a gauge to be sure because it's mechanical
Which I would trust more.

If it's in the pan, it's more an average temp than peak. Peak is what's most important. I think the factory sensor is internal to the trans, so it likely always reads higher.

As for accuracy, we're talking about either eyeballing an analog gauge or whole numbers for a digi-gauge. It's accurate enough, and the 270* sweep e-gauges are pretty damned accurate (like 0.1% or less error). Not enough to matter, especially when you're mainly looking for out of the ordinary temps.

Desert Captain wrote:
Scan Gauge will display Ford trans fluid temperature through the "X" gauge function. Go to their website or better yet just give them call. Different years/models will require different codes but they are easy to enter at set up.

If you don't know your trans fluid temp then just keep it in Tow Haul on anything but a flat or mild downhill grade. Even a slight grade, 2 - 3%, can elevate your trans fluid temps after just a couple of miles.

:C

I run mine in tow/haul 100% of the time. It's hauling a house 100% of the time it's driving. :B

[Desert_Captain]

Scan Gauge will display Ford trans fluid temperature through the "X" gauge function. Go to their website or better yet just give them call. Different years/models will require different codes but they are easy to enter at set up.

If you don't know your trans fluid temp then just keep it in Tow Haul on anything but a flat or mild downhill grade. Even a slight grade, 2 - 3%, can elevate your trans fluid temps after just a couple of miles.

:C

[RacerX10]

What app are you getting transmission temp with ? I got a higher end OBDlink lx reader and the software that comes with it isn't picking up trans temp.

I also got the Torque app, but can't seem to get that reading it either.


EDIT - I got it working with the custom 1E1C PID .. thanks !

[Desert_Captain]

As long as your trans temps come back down when the load is reduced things are working as they should. Any trans under load will generate higher temps, 215 to 230 for brief periods should not be a problem.

I recently saw 230 for about 30 seconds but we were climbing out of Panamint Springs in Death Valley with an ambient temp of 104(fully loaded and pulling a 960# trailer/motorcycle). As soon as I backed off the throttle dropping us back to 40 mph from 45 the temp dropped like a stone and the engine coolant temp never rose above 220.

This was a very rare event with normal operating trans fluid temps running around 185 to 210 on our 2012 E-350, V-10 (24' Class C), with the 5 speed Torque Shift trans. I did switch to pure synthetic trans fluid when I bought the coach and that certainly helps.

The key to this equation is to know what your trans temps are, (I use a Scan Gauge), and then engage the Tow Haul mode sooner rather than later to help control/dissipate the heat before it becomes an issue.

As always..... Opinions and YMMV.

:C

[pauldub]

I have an '03 24' Winnie on an E450 chassis. Towing my 4000 pound Cherokee over a 10,000 foot pass last week in first gear, I got up to 215 degrees as displayed by my scangage. My total weight is almost 16,000 pounds. Tranny fluid is Mobil 1 and I have the OEM tranny cooler. This is the highest temp that I've ever seen and it's the first 10,000 foot pass that I've had it over.

[tommykelly]

"If" that is the correct temp..the very first thing is to see if dirt ..leaves are trapped between the cooler and radiator..before you start thinking about changing anything...always check the simple first...

[ChooChooMan74]

Transmission temps are dependent on type and fluid. My ZF will use the coolant to heat up to 190 to 195. Yours doesn't seem overly hot, but I would check with who manufactures your transmission.

[mlts22]

To borrow a few graphics:





I would probably go ask a Ford mechanic who is familiar with this decades's transmissions and get an authorative answer. Heat kills transmissions quickly, and even with materials design, ATF is still ATF, and will cook/coke at high temperatures.

If you are continually seeing those temps, I wonder if a transmission cooler upgrade is in order. It might be wise to see about replacing it, if the factory cooler is the same tiny size as pictured on this link:



(Bottom cooler is for the trucks, top for Econoline models.)

[Chopperbob]

My 2001 never sees anything close to that. I have a manual guage. They must have done something different in the newer models. If I we're you I would install a gauge to be sure because it's mechanical
Which I would trust more.