Help with Tranny Temps

[Glen5241]

I recently installed a gauge set on the truck. Now, I can see what is going on and today, I saw something that kinda worried me. I have a 34' Rage'n 5th wheel toy hauler ordered. It should be done around the end of the month. I also have an enclosed trailer for my snowmobiles and also have two ATV's in it. I picked up the one trailer this afternoon to do some work on the quads. The weather has gone from nice to way too hot. It was (is) over 100 today. I picked up the trailer and had to tow through town to get home. I must have hit every stinkin' light in town. The trailer probably weighs around 5k lbs as it sits loaded. The tranny temp went right up to 190. I haven't noticed it that high but this is the first tow with the gauges and also being so hot outside. Just last week, the weather was cool, 70-80, and the tranny ran around 140-150. I just changed fluid and used Royal Purple, changed my Magnefine filter, tranny filter and checked everything. I have the Sonnax valve and Tri-C springs in the valve body. Stock torque converter. Only 49k miles on entire truck. Am I being over cautious? The 5th wheel will weigh around 9k lbs unloaded. Any thoughts or suggestions? I am open for anything to help possible problems or prevent them. Thanks for the assistance in advance. I've always received great advice from the forum, don't let me down, I'm almost in a panic......

[Mark Kovalsky]

Where are you reading the trans temp? 190F isn't all that hot.

[444-4D]

Originally Posted by Glen5241

Am I being over cautious?

Yes, and in a panic for no reason.

[chuckster57]

So 190 isn't bad. It seems like everything I read says that trannys start to go south faster at about 190 degrees. I am looking at an aux. remote fan controlled cooler. My gauge reads 185-190 empty reading at the high pressure port. I was under the impression that 150-165 was the best for tranny fluid.

[Longtrailer48]

Stop and go, converter constantly unlocked, 100 degree heat, very little air blowing over the cooler? That will take a very well cooled tranny to 190 which is just fine. That same set up pulling a grade at 40mph+ with the converter locked will probably run cooler. You're panic is unneccessary.

-Jeff

[Glen5241]

Thanks for all of the thoughts. The temp sensor is in the high pressure port of the E4OD. I wanted to give as much info as possible and see what everyone has to say. I was concerned since I was not pulling much weight, but it was stop and go, and the temp went up quickly. Do temps show higher in the pressure port than if the sensor was mounted in the trans pan? Just curious. Thanks again.

[Griz]

Originally Posted by chuckster57

I was under the impression that 150-165 was the best for tranny fluid.

Actually Ford says the sweet spot for the transmission fluid is 160-170 degrees. That is where it is the most efficient...less drag etc. It appears you are doing just fine.

Griz

[SmokeyWren]

Originally Posted by Glen5241

Do temps show higher in the pressure port than if the sensor was mounted in the trans pan?

I'm not sure about the E40D, but for the later 4R100 in the SuperDuty 7.3Ls, the two temps are almost identical. The E40D and the 4R100 are almost identical except for some beefed-up parts in the 4R100, so I suspect your setup is giving you "sump temp".

Don't be concerned until you see over 210º tranny temp. If you see over 210º, then consider changing to synthetic ATF and adding tranny cooling capacity. The only time you should see 210º is heavy load, slow speed, and a good grade. Stop and go traffic while towing an 8k trailer in 100º weather will get the tranny temp up around 200º on mine.

Even with a heavy trailer and climbing a mountain pass, cruising at over 40 MPH should not get the tranny temp over 200º. Where you can get in trouble is when climbing a steep grade at less than about 40 MPH, when the torque converter unlocks and begins spewing a volcano worth of heat at the coolers.

About 225º to 230º is the red line. Ford says 221º, but then Ford says it's okay to get a little hotter if you can see the end of the tunnel (or the top of the pass) ahead.

I've never seen over 205º on mine, with over 170,000 miles of mostly-towing miles in every mountain range in the lower 48. But if I ever saw 220º I'd begin looking for a place to pull over and stop and cool off the tranny at high idle RPM.

[chuckster57]

Originally Posted by SmokeyWren

Don't be concerned until you see over 210º tranny temp. If you see over 210º, then consider changing to synthetic ATF and adding tranny cooling capacity. The only time you should see 210º is heavy load, slow speed, and a good grade. Stop and go traffic while towing an 8k trailer in 100º weather will get the tranny temp up around 200º on mine......About 225º to 230º is the red line. Ford says 221º, but then Ford says it's okay to get a little hotter if you can see the end of the tunnel (or the top of the pass) ahead...... if I ever saw 220º I'd begin looking for a place to pull over and stop and cool off the tranny at high idle RPM.

Thanks for the info. I hauled my 5er for a lot of yrs. using my old '86 F250 460/C6. I put in a 165 Tstat and never saw over 170 on the tranny. I am still learning the Diesel way and understand that diesels like to run hotter. My son (naval Officer & masters degree in Mechanical eng.) and I have had many "discussions" about tranny temps and other things automotive. I will still probably install a remote cooler w/fan, since I have gauges and I will set my "mind" to use it at about 200 degrees. thank you again for your information. I joined this site to learn. and it has been a pleasure so far

[redtopman]

For my old 97 the temps you mentioned are about what I get pulling 10.5K. My tranny gauge was connected into the test port, drivers side, of the EO4D.

Going up grades I may reach 210

[Glen5241]

Lots of good input! I recently flushed and changed the tranny fluid and refilled with Royal Purple Max ATF. A lot of people recommended that as it is a synthetic and usually RP is a very high quality product. I do have an aftermarket cooler. I run a Tru-Cool stacked plate. Can't remember the model but it was one of their larger ones. Thanks again

[SmokeyWren]

Originally Posted by chuckster57

It seems like everything I read says that trannys start to go south faster at about 190 degrees.

Way back when - 30 or so years ago - ATF would begin deteriorating at around 175º, and the hotter it got the faster it deteriorated. By the time it reached 225º, it was going south in a hurry. And ATF that has deteriorated too much will ruin the clutches in an automagic tranny in a heartbeat.

But ATF has improved a lot since then. And synthetic ATF has improved a lot more than the good dino ATFs, such as Chevron. Chevron Products: Our Fuels: Products and Services: Automatic Transmission Fluids: Multi-Vehicle

But marketers of tranny coolers and synthetic ATF continue to publish those old ATF deterioration charts from way back then - because it helps sell coolers and high-priced synthetic ATF.

I haven't seen an up-to-date ATF chart that shows temp capability. But if I did find one, I'm sure it would say that dino ATF is okay over 200º, and synthetic ATF is okay up to around 225º.

The following is one of those 30-year-old charts that you should not use. AMSoil included this one on their website until recently, but it's not there now, so I guess they finally saw the light.

Originally Posted by obsolete ATF temp chart

Automatic Transmission Fluid Oxidation
Automatic transmission fluid will provide 100,000 miles of 
service before oxidation occurs under normal operating 
temperatures of about 170°F. Above normal operating 
temperatures, the oxidation rate doubles (useful life of 
fluid is cut in half) with each 20° increase in temperature.
 
 
The approximate life expectancy at various temperatures is as 
follows:
 
175°F   100,000 miles
195°F    50,000 miles
212°F    25,000 miles
235°F    12,000 miles
255°F     6,250 miles
275°F     3,000 miles
295°F     1,500 miles
315°F       750 miles
335°F       325 miles
355°F       160 miles
375°F        80 miles 
390°F        40 miles
415°F     Less than 30 minutes
 
This information clearly shows why transmission oil coolers 
and the various maintenance intervals are recommended for 
severe usage.

[chuckster57]

Looks like the same one I saw on a different web site. I too changed my fluid and filter and put in 7 qts. of Royal purple "max ATF". I guess some "old school" ideas are harder to shake than others. Thanks again for the update

[444-4D]

Originally Posted by chuckster57

Looks like the same one I saw on a different web site. I too changed my fluid and filter and put in 7 qts. of Royal purple "max ATF". I guess some "old school" ideas are harder to shake than others. Thanks again for the update

You only changed half of your fluid.

[Mark Kovalsky]

Less than half. The trans hold about 18 quarts.