Transmission temperature max of 240 deg. sound right?

[Oklahoma_Dan]

I am doing a double trailer pull (5th wheel + Can Am Commander)in Colorado with my 7.3L diesel F250. Having just installed a larger trans. cooler with a temperature gauge I was told that I should keep my transmission under about 240 degrees. For those in the know, does this sound about right when you are doing a hard pull up a steep grade?

[SandSOrrell]

Try keeping your eye on the tranny temp when you are spending a lot of time trying to back your rig into a difficult spot. You will see it go up then.

:B

When I'm tryng to back into a difficult spot, I've got all I can do to keep my eyes on my mirrors and my DW giving me confusing signals!

[wilber1]

SandSOrrell wrote:
I've just returned from a trip from Texas north through OK, KS, NE, SD WY, ID, UT, CO, NM, and back. Lots of long mountain grades. I have a 2013 Chevy 1 ton Duaramax/Allison DRW 4X4. Trans temp never got above 180 as far as I know (and I checked it often in the mountains). 240 would be alarming to me. But again, I've got a new truck with less than 12,000 on it.

I don't want to start a brand war here but my Chevy D/A is a towing machine! On I-70 through CO, I set the cruise at 60, put the trans in Drive, Tow/Haul mode, and exhaust brake on and the truck never broke a sweat and I VERY seldom had to even touch the brakes on the downhill grades. I'm very happy.

Again, a lot depends on where the readings are taken. The 68RFE in my 2011 RAM runs around the same temperatures as your D/A, don't think I have ever seen 180 pulling.

This is where the new transmissions are quite different. Their torque converters remain locked in most of the lower gears where the old 4 speed just locked in 3rd and OD unless modified. If the converter remains locked, high ambient temperatures don't effect transmission temperature very much. Try keeping your eye on the tranny temp when you are spending a lot of time trying to back your rig into a difficult spot. You will see it go up then.

[64thunderbolt]

Puddles wrote:
If your truck is a 2000 or older, Ford has a radiator available that will alow tranny oil to go thru it and be cooled... does a much better job than a air type cooler... I wouldn't like to see oil temps above 210 anytime. That cooler water in the bottom of a radiator is a life saver for the transmission.

Early 99 is the only one that had no rad cooler. 99.5 & up had them The rad cooler is more for warm up. On my E99 I added a trucool and cannot make mine get hot. 240 won't hurt it unless it stays there for a while.

On 9/11 miles of 6/7% I will just get to 180* when I top out. In 90/100* temps. Now in cold weather it won't be good it never warms up. The reason they decided to run it through the rad.

[ace44]

I think it depends on where your temp sensor is located. Here is a guide I have always used. My sensor is between transmission and cooler, so basically just out of torque converter and I have seen 260 before.

Automatic Transmissions

OIL TEMPERATURE MEASURED AT CONVERTER OUTLET TO COOLER:

300° F=
The maximum allowable temperature. This is the recommended place to install a temperature gauge or sensor. Do not allow the converter outlet temperature to exceed 300° F. The temperature at this location will vary significantly because of load, hill climbing, etceteras. If the temperature reaches 300° F, reduce throttle. To lower transmission temperature with transmission in neutral, run the engine at 1,200 RPM for at least 2 - 3 minutes while keeping a close check for signs of engine overheating. A transmission in a heavy throttle, stall condition (a typical situation is rocking a vehicle stuck in mud, sand, or snow), may increase temperature at a rate of 1° degree per second of stall.


OIL TEMPERATURE MEASURED AT OIL PAN OR SUMP:

150° F=
The minimum operating temperature. Note: It is possible in low ambient temperatures to overcool the transmission with auxiliary oil to air coolers. Oil to water coolers in standard factory radiators will normally not overcool a transmission.


175-200° F=
Normal pan oil temperature operating range.


275° F=
Maximum allowable oil pan temperature for short durations during long hill climbs.


300° F=
Damage occurs to internal transmission parts, including warpage of metal parts, degradation of clutches, and melting of seals. Transmission oil oxidizes, (forming varnish-like substances causing further clutch slippage and compounding heat build up) and transmission oil life is extremely short.

[SandSOrrell]

I've just returned from a trip from Texas north through OK, KS, NE, SD WY, ID, UT, CO, NM, and back. Lots of long mountain grades. I have a 2013 Chevy 1 ton Duaramax/Allison DRW 4X4. Trans temp never got above 180 as far as I know (and I checked it often in the mountains). 240 would be alarming to me. But again, I've got a new truck with less than 12,000 on it.

I don't want to start a brand war here but my Chevy D/A is a towing machine! On I-70 through CO, I set the cruise at 60, put the trans in Drive, Tow/Haul mode, and exhaust brake on and the truck never broke a sweat and I VERY seldom had to even touch the brakes on the downhill grades. I'm very happy.

[cummins2014]

wilber1 wrote:

up2nogood wrote:

wilber1 wrote:
Depends a lot on the location of the probe. If it is in the transmission outlet before it gets to the cooler, 240 pulling a grade with the torque converter unlocked or backing up a heavy trailer wouldn't be unusual, but it should cool down again very quickly once the converter locks up again if you have a good cooler. 240 anywhere else would be high.

Test port above the second transmission pan bolt from the front drivers side is where the sending unit needs to go. ATF goes from the pan thru the oil pump ,and then past this port. This location for the sender will give you pan oil temperature, or very close. Safe temperatures are anything below 200 ,200-225 is the warning , over 225 is too hot. Why do you want the temperature of the oil going to the cooler, what you want is the temperature of the oil getting pumped into the transmission ,not what it ends up coming out. Regardless it has worked well for me for 8 years of towing heavy ,and never seeing 200 .

I'm not familiar with the 4R100 so I will take your word for it. I agree that as far as transmission components go, you want to know the temperature of the oil in the transmission itself but the peak oil temperature will be when it leaves the torque converter.

If you are pulling up a steep grade with the torque converter unlocked or backing a heavy trailer up a slope, if you have an efficient cooler, the fluid temperature leaving the torque converter can easily be above 250 even though the pan temp is much lower. This gives me a problem with charts that say you should be changing fluid every 6,000 miles if your fluid temp goes over 250. If that's the case, everyone towing in mountains that don't have torque converters that lock in lower gears should be changing fluid every 6K. I don't think so.

I guess that is the beauty of having a tuner that locks the torque converter in the lower gears, probably the biggest reason I have no heat problems towing heavy. I am curious as to what the oil temperature is coming out of the transmission ,but not having problems so not concerned. 250 sounds pretty high to me , the oil is starting to break down at those temperatures. I change mine at 30K . A lot of my towing is in the mountains, Utah ,Idaho, and Montana. I will just keep doing what has been working.

[jwduke]

Take a look at this Transmission cooler for a Ford Truck. The price is a little rough, but if it cools as good as their stats say, it is cheap if it adds life to a expensive transmission replacement.

[wilber1]

up2nogood wrote:

wilber1 wrote:
Depends a lot on the location of the probe. If it is in the transmission outlet before it gets to the cooler, 240 pulling a grade with the torque converter unlocked or backing up a heavy trailer wouldn't be unusual, but it should cool down again very quickly once the converter locks up again if you have a good cooler. 240 anywhere else would be high.

Test port above the second transmission pan bolt from the front drivers side is where the sending unit needs to go. ATF goes from the pan thru the oil pump ,and then past this port. This location for the sender will give you pan oil temperature, or very close. Safe temperatures are anything below 200 ,200-225 is the warning , over 225 is too hot. Why do you want the temperature of the oil going to the cooler, what you want is the temperature of the oil getting pumped into the transmission ,not what it ends up coming out. Regardless it has worked well for me for 8 years of towing heavy ,and never seeing 200 .

I'm not familiar with the 4R100 so I will take your word for it. I agree that as far as transmission components go, you want to know the temperature of the oil in the transmission itself but the peak oil temperature will be when it leaves the torque converter.

If you are pulling up a steep grade with the torque converter unlocked or backing a heavy trailer up a slope, if you have an efficient cooler, the fluid temperature leaving the torque converter can easily be above 250 even though the pan temp is much lower. This gives me a problem with charts that say you should be changing fluid every 6,000 miles if your fluid temp goes over 250. If that's the case, everyone towing in mountains that don't have torque converters that lock in lower gears should be changing fluid every 6K. I don't think so.

[Turn_Key]

Seems a bit high to me but it is within "safe" range. Highest I've ever been is about 210 degrees after a long up-hill pull. Not pulling as much as you, though. What's your "normal" temp when driving truck sans trailer? I run about 70 degrees above ambient temp when not pulling and add about 25-30 degrees when pulling "5th" on a flat and level stretch. Hope this helps.

Happy Camping!

[cummins2014]

wilber1 wrote:
Depends a lot on the location of the probe. If it is in the transmission outlet before it gets to the cooler, 240 pulling a grade with the torque converter unlocked or backing up a heavy trailer wouldn't be unusual, but it should cool down again very quickly once the converter locks up again if you have a good cooler. 240 anywhere else would be high.

Test port above the second transmission pan bolt from the front drivers side is where the sending unit needs to go. ATF goes from the pan thru the oil pump ,and then past this port. This location for the sender will give you pan oil temperature, or very close. Safe temperatures are anything below 200 ,200-225 is the warning , over 225 is too hot. Why do you want the temperature of the oil going to the cooler, what you want is the temperature of the oil getting pumped into the transmission ,not what it ends up coming out. Regardless it has worked well for me for 8 years of towing heavy ,and never seeing 200 .

[Atom_Ant]

I would wonder how accurate the gauge is at the high side as well.

[wilber1]

Depends a lot on the location of the probe. If it is in the transmission outlet before it gets to the cooler, 240 pulling a grade with the torque converter unlocked or backing up a heavy trailer wouldn't be unusual, but it should cool down again very quickly once the converter locks up again if you have a good cooler. 240 anywhere else would be high.

[cummins2014]

overthehillbill wrote:

kampinguru wrote:
I have a 2000 7.3l F250 and have had the 6.0 oil cooler installed. You do not want to be at 240 for very long. Check the smell of your tranny fluid on the dipstick. If it smells burned, you have been too hot. I also have the BTS transmission installed and I do not see temps above 160 anymore. I run Scheffers synthetic fluid in the truck as well.

X-2. I have the John Wood Towmaster tranny with the 6.0 tranny cooler.
The stock 4R100 tranny is the weak link if you are towing heavy.

I agree they are the weak link, but IMO the weak link was the cooling, and not so much the tranny. I am still running the stock tranny in my early 99. As I said been towing heavy for the past eight years, but have had the 6.0 cooler. The inadequate cooling killed a lot of the 4R100's before the 6.0 cooler even showed up. If I had been towing heavy with mine early on I probably would of burnt it up also. There is nothing on my truck before I installed the temperature gauge to even tell me if I was overheating. Many were probably overheated and ruined before they knew it.

[cummins2014]

Oklahoma Dan wrote:
Thank you for all of your replies as well as the in-depth research. You guys are great. When installing the larger trans. cooler and gauge I also had them flush completely the transmission, put in a new filter and put in BG brand synthetic fluid. The old fluid (about 12,000 miles old) was a little off color which prompted me to make improvements during this vacation. Once I am home I may go to a deeper pan as well. All good suggestions.

I have had the 6.0 cooler on mine nearly as long as I have been towing heavy about 8 years early 99 7.3. 185-190 on long mountain grades in 90 plus degrees. 240 IMO is going to get that 4R100 eventually. Have never read where that deeper pan did anything but give you more fluid to cool. It is not the answer, a 6.0 31 row cooler is all you need. Not sure what you mean by installing a larger cooler, if it is a 6.0 31 row, you shouldn't see over 200, with mine towing 13K, like I said ,185-190 is the extreme. You may have a problem that a cooler won't fix.