Trans cooling

Your ATF temp is within the normal range for both the fluid and the transmission. If the temp needed to be lower the manufacturer would have put on a larger cooler or added a fan as is done with radiators. The ATF is fine up to over 350 degrees.

For heavy towing it is worthwhile to get the better TES-295 ATF such as TranSynd. It will also provide twice the life so you can change the fluid less often.

mikewats wrote:
I have installed an additional trans cooler with fan on my 2006 Dodge diesel 5.9. My cooling temperature on the Hwy is 165, however in town traffic it shoots up to 200 to 212. I thought about installing a larger oil pan with an additional 4 qts. Has anyone done this with success? I pull a 2011 Carriage Cameo. Any help on cooling down this thing would be greatly appreciated .

Thanks

Mikewats

I'm sure you have heard this before, but the trans you have is not tolerant of a whole lot when too hot and subjected to the 5.9's. torque. 3 loggers I know switched from Fords to 2005-2006 cummins 5.9's, they are all selling or sold, all of them rebuilt (trans -48RE I believe?) at least once. 3 for 3 is pretty convincing to me.....

Their observations were "they just don't last". I questioned if it was heat or maintenance that killed them. They all had the towing package, and all were towing under the rating, mostly lower profile / heavy trailers containing wood.

Anyhow, a larger cooler would be a good idea IMO, and fluid changes every 50K are the way to go, but that's just my opinion, based on experience.

I agree with all posts on the torque converter being unlocked in stop and go traffic causing a "fluid coupling" rather than a direct mechanical lock up. You need to watch your tachometer to see how the extra rpm is reduced as the torque converter locks. Read the owners manual, my 05 states to put the tow haul button on and pull the shift lever into D2 when going up steep long grades. This forces the torque converter to remain locked as long as the speed is above 30 mph. My aftermarket personally installed temperature guage in the output line from the transmission shows me instaniously what the temperature is doing. When the torque converter locks the temps come down immediately. In stop and go traffic there is no way to lock the torque converter so temps will rise. After 230 for prolonged periods I begin to worry and look for a pull off. Putting the transmission in Park stops the fluid movement through the output lines and cooler, thus temps will not come down. Leave it in Neutral and run the engine at fast idle as long as you can, this cools the fluid more quickly.

All great advice thanks to all that responded!!

You'd do better to add a supplementary transmission cooler--like a TruCool or one made by B&M. They can be bought for around $150, and they'll lower your temperatures substantially.

Best insurance anyone towing can get for their rig.

It's a simple 30 minute installation--cutting one rubber hose and plugging a hose into each end with clamps.

I have always used a 2nd trans cooler w/fan manually controled, which I mounted under the bed of the truck...I spiced the cooler in the return line just before the trans.When my temp started to climb a little too high just turn on the fan an temps would drop...When towing heavy in 92* temps that cooler helps....I also have 2 temp gauges there is one for trans temp,my 2nd gauge is mounted to the trans cooler output line(made a bracket to hold the sender against the line)...as for fluid the ATF+4 is a synthetic fluid,which walmart sells

wintersun wrote:
Your ATF temp is within the normal range for both the fluid and the transmission. If the temp needed to be lower the manufacturer would have put on a larger cooler or added a fan as is done with radiators. The ATF is fine up to over 350 degrees.

For heavy towing it is worthwhile to get the better TES-295 ATF such as TranSynd. It will also provide twice the life so you can change the fluid less often.

Bad advice. The OP should use only ATF+4 (which can be had in synthetic).


Dodge/Ram has put out a TSB that applies to vehicles up to 2007 that says using the wrong fluid (anything other than ATF+4) can cause clutch chatter.

I see 175* on the highway, 190* or so towing and max of about 200* in traffic with the TT. Since you are nice and cool at 165* on the hiway, that says you have plenty of cooling capacity, but the spike when stopped would cause me to look at the fan clutch. How are engine temps, do they go up too? Usually a big spike like that is from lack of airflow over the cooler...

If the fan clutch turns out to be OK you might look at an aux electric fan that you can turn on, or have it controlled by a sensor and relay.

Adding more fluid capacity doesn't fix the heat issue it just takes longer to heat up...which also means it takes longer to cool down. Again, it sounds like your issue is inadequate airflow over the cooler when stopped.