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View Full Version : Tranmission temperature while towing



dieselengineer
10-15-2008, 03:55 PM
Does anyone monitor their tranny temps while towing? If so, what is the temp for the type tranny.

ibrick
10-15-2008, 05:13 PM
I monitor my 4R100 auto in my F350 DRW all the time when towing our 3055.
Highest temp ever reached was 200 in rush hour stop and go city traffic. Just returned from a trip through the Rockies and my highest temp was 190 while climbing, I also slowed down and put it into tow/haul when I saw the temp climbing through 175. I'm sure it would have climbed higher leaving OD engaged and as temps are very dependent on ambient temperature. It was a very cool, late evening when I did that portion of the trip.
Running empty I rarely see above 160 even on the hottest day pushing it hard.

davebennington
10-15-2008, 05:14 PM
I have a temp gauge on the hot line from the tranny before it gets to the coolers (factory and a aux I installed). I usually run about 160 towing and it may get to 190 when I am in traffic or backing up. I also installed a double deep Hy-Tec tranny pan.

Very rarely do I see temps over 190, hot day sitting in traffic maybe.

Dave

bigchief
10-15-2008, 07:21 PM
With my 2008 GMC diesel I do about the same. 140 to 160 normal and
190 puling. Never been over that.

Cirrus
10-20-2008, 11:46 AM
I learned this from a guy over at "The Diesel Place" forum......
I good rule of thumb is tranny temps will usually stabilize at about 100 F over ambient temps when towing. (this is ballpark only, but it does help).

davelinde
11-14-2008, 07:13 PM
yes, I watch tranny temps on my 2004 Dodge - it's a 4-speed designated as 48RE and I tow with OD locked out.

Right now I'm towing 14,000# (21,700# combined gross) and I can see trans temp spikes in a lot of circumstances. I actually have two gauges, one on the hot-line output and the other tapped the factory internal sensor. The hot line output stays around 140 most of the time, however the internal sensor will run at ambient +120 degrees on the highway.

Towing long grades or steep grades will tweak my temps. And, of course, any time I end up doing stop and go, or stop and go on a hill... the temps will climb a lot. The internal gauge is typically higher all the time, but the hot line sensor will respond faster and zoom past the internal in 30 seconds if I hit it hard from a stop up a hill.

I've towed this setup about 5,000 miles so far and the highest temps I've seen are around 250 on both gauges. The highest sustained temp I've seen was about 230 pulling hills in PA - but only on the internal sensor. The hot sensor was around 160 then.

So... it depends on where you measure for sure.

Pull Dog
12-31-2008, 07:48 AM
My 05 Cummins with 48RE runs around 175 on normal hot days but like some of the posts state it will be dependent on the ambient temperature you are running in. You can count on it running around 90 degrees above ambient while underway. Spikes will occur under certain driving conditions but from what I have read this does not hurt the fluid if its only for a few minutes. Some things I have noticed though are worth mentioning. Backing up or driving in stop and go very slow traffic for extended periods will push the guage to over 200. My gauge is located in the output line from the transmission. As soon as I begin moving forward at a continuous speed the temp drops dramatically back to normal. I consider 160 to 180 a normal range. Another important thing I have learned while driving in the mountains. Never never pull a long hard grade and then pull over at the top to rest or take pictures. You are generating significant heat when pulling hard and the sudden stop before the coolers have time to bleed off the heat will cause your transmission to drastically overheat. Fluid does not live long in this situation!! Always crest a hard pull and then drive a few miles to let her cool down before shutting down the engine!! Those large dark spots in the pavement at overlooks are from people who came up and abruptly stopped, shut down the engine and heard their wife say " honey what is all this red stuff on the ground under the truck"

Ray LeTourneau
12-31-2008, 08:41 AM
We have the LB7 Duramax/Allison. Not towing ranges from 150 to 160, towing no hills, 190 or so. Hills it will get in the 220 area.

rickbsgu
01-13-2009, 01:13 AM
Ford F350 SRW 4x4, built transmission, pulling a 3670RL.

This has been a point of concern, for me - I've been watching my temps get into the 200 degree range pretty consistently when I'm pulling a hill. Takes a while to get there, takes a while to cool down, too. Driving around town, it went up to 220. I shut it down and got some diesel.

When I shut it down, it seems to cool back down to 100 within about 20mins.

I don't know if I should be concerned or not - I need to talk to my tranny guy about it.

tkdmike
01-15-2009, 09:24 AM
I maintain about 140 empty and 175 towing unless its exceptionally hot or hilly - then can get to 200. I have upgraded by putting a tranny cooler from a 6.0 liter Ford diesel in my 7.3 and adding an aftermarket cooler and filter.

Have overheated once in a light truck (F250) coming over Wolf Creek Pass with 10k lb fiver and torque converter and exhaust break used to maintain safe speed. Other than that, no issues.

jwb187
01-15-2009, 12:50 PM
2005 GMC duramax cc 4x4 normal driving no trailer warmed up around 160, pulling 3055 5'ver most I've ever seen on 105 degree day on 65 north of Branson pulling one of those long hills was between 200 and 210. And I'm supposed to have one of those overheaters, hasn't happened yet.

leftyf
01-15-2009, 12:55 PM
I maintain about 140 empty and 175 towing unless its exceptionally hot or hilly - then can get to 200. I have upgraded by putting a tranny cooler from a 6.0 liter Ford diesel in my 7.3 and adding an aftermarket cooler and filter.

Have overheated once in a light truck (F250) coming over Wolf Creek Pass with 10k lb fiver and torque converter and exhaust break used to maintain safe speed. Other than that, no issues.

Having been over the same creek WITHOUT towing anything..that truly is saying something.

GEugeneS
01-17-2009, 05:35 PM
I run about 160 pulling 15K with my F350 on a 4R100. Pulling in the Sierra's going to 6 or 7 thousand feet, I have seen it go to 215 for a minute or two, usually at the top of the grade.

NewCyclone
03-13-2009, 04:13 PM
I have a temp gauge on the hot line from the tranny before it gets to the coolers (factory and a aux I installed). I usually run about 160 towing and it may get to 190 when I am in traffic or backing up. I also installed a double deep Hy-Tec tranny pan.

Very rarely do I see temps over 190, hot day sitting in traffic maybe.

Dave

Dave, did you install the transmission pan yourself? I am seriously thinking about adding that to my truck since tempratures here in the high desert can reach 120 easily. 4wheelparts.com has the pans on sale right now. How much fluid does the transmission hold? Curious how hard the install was.

chrischaster
02-07-2010, 11:40 PM
As soon as I get the chance I will post my temps for the '06 dodge megacab dually auto with the BD pan.....

porthole
02-08-2010, 12:11 AM
Wide range of temps here for sure.

140 after the cooler isn't saying much.

140 in the trans then the trans is not warmed up.

I don't know where GM pulls the temp reading from and I never really followed the gauge with the old TT.

I put in a Banks tuner with the PDA and that includes a digital temp gauge (from the trucks ecm). There are also alarm limits that can be set.

Most of the time it stays around 190-200, which is operating temperature.

I did hit 240 coming back from the PA rally last summer when I made a wrong tune and went up a very steep hill, 14 degrees IIRC.

The Banks engine temp and trans temp alarms were going off :eek: I think the limits for both were set for 235.

Something to consider, when I was a dealer tech we never considered a trans fully warmed up until the vehicle has been driven about 10 miles, preferably highway miles.

After that the fluid level can be checked. And a quart overfilled is just as bad or worse then a quart underfilled.

rumaco
02-08-2010, 07:51 AM
PULL DOG makes a perfect statement concerning temps in transmissions. He is exactly right! We pull many commercial hauls and one of the sins of travel is stopping when very hot, it causes boil off and there is no air or flow to carry the excess off. In our experiances without trailers attached the temps are ambient plus 100 degrees. Trailers on any where between 125 and peaks of 220-235. I have found one thing though, we put ATF by amsoil in the truck we pull our 3580R and the temperature dropped an average of 50 degrees across the board, don't know why it just did.

rumaco
02-08-2010, 07:53 AM
I also installed a much larger transmission cooler. Costs about $450 installed but what a differance. Coolers only work above 35mph so there is a key.

bill40
02-08-2010, 09:12 AM
I have noticed that with the Banks system my temp. have been a lot cooler than prior to having it. I think the big intercooler has helped with both water and trans temps.
During our last trip out west I saw a temp of 190(trans) leaving Needles. It was 126 that day and that is a 14.5 mile climb at 7%. The down side is I have to run a front cover this time of year or the trans temp and water stay below operating temps.

driver311
02-08-2010, 09:19 AM
if coolers only work above 35mph how do tractors keep there oil cool????????

driver311:angel::angel:

porthole
02-09-2010, 12:40 AM
I turned the trans temp on today (Banks PDA).

After 23 milles, all but 2 highway and at 23 degrees F my trans temp was all the way up to 118F.

By the time I got to work, 35 miles, it hit 126F.

I'm sure if I ws pulling the trailer it would have at least been in the 170-180 range.

I would say 126 is way below operating temp, but the only work it was doing was pushing the truck along at 75.

newbie
02-16-2010, 09:09 PM
I have a small Kubota and I can tell you for sure that the transmission (which is also the hydraulic oil) gets really hot when working it in the summer. That's why even the small tractors have oil coolers and fans.
Back to the OP, my trucks OEM transmission temp guage runs 190 pulling heavy in the summer. Until I pulled some steep grades in the West Virginia mountains, I had never seen hotter than 208 which was in bumper to bumper freeway traffic with the air temps about 100. Pulling a long 9% last summer, that started at a hairpin curve at almost a dead stop with full water tanks and fully loaded with gear, I hit 230. I started getting nervous but never got a warning light.

The guys over at Diesel Place say that's normal for a heavy pull in the mountains in hot weather. IIRC you won't get a warning light on the Allison until about 250 degrees.

escs36
02-18-2010, 01:28 AM
i have found that trans temps are directly related to RPM's. i have 3 trucks. f350 with 4.10's and the temps barely hit 165 pulling heavy. f550 with 4.88's pulling my 3912 runs at 195 in the hills. f650 with allison 5 speed, 4.88's runs 165 all the time. all these trucks have added coolers installed. the truck with the lowest rpm's has the lowest temp. also my f650 temps will run 195 cruising flat grounds on the highways if i run above 2300rpm.

PUG
02-18-2010, 12:33 PM
My 02 Duramax towing ran about 100 degrees over outside ambient in tow haul mode. My 09 Dodge 3500 in towmode runs about 80 degrees over outside ambient. It makes a difference if you use tow haul or not. I only tow in tow haul mode which keeps slipage down and temps down. I have Isspro trans guage, pyro, and boost that I purchased from Dieselmanor .com.

rumaco
03-13-2010, 06:26 PM
Ambient +100 is standard and is about correct for trailerless rigs. I changed to Amzoil (No I am not a salesman or fan) simply because of a friend that stated it dropped the overall temp X 50 degrees and it did. The Ford OD off (trailer mode) is great below about 60 MPH but above we can't deal with the revs. After research of all rigs I have found that the design of the trailer tow does not consider over 60-65mph ranges. Tow mode will keep EGT down, Boost up and Trans temp down. I am absolutely amazed that a F350 with 4.10 only hits 165 degrees........................ours hit about 195-200 with very heavy loads (not too sure what your heavy is, but ours is about 23,000 lbs trailer only)



My 02 Duramax towing ran about 100 degrees over outside ambient in tow haul mode. My 09 Dodge 3500 in towmode runs about 80 degrees over outside ambient. It makes a difference if you use tow haul or not. I only tow in tow haul mode which keeps slipage down and temps down. I have Isspro trans guage, pyro, and boost that I purchased from Dieselmanor .com.

porthole
03-13-2010, 07:01 PM
50 drop????

The primary benefit of synthetics is that they maintain their lubricating properties at higher temps, not that they have built-in air conditioning.

rumaco
03-13-2010, 07:15 PM
Not sure what you mean by buit in air conditioning but here are the specs:

Trip 1 FORD ATF Idaho to Port Angeles WA ..........trans temp average 197 degrees (through Oregon and dead mans pass) OAT 88 F
Trip 2 FORD ATF Idaho to Port Angeles WA...........trans temp average 188 degrees (through Oregon and then up I 5 to Seattle) OAT 55F
Trip 3 FORD ATF Idaho to Port Angeles WA...........trans temp average 200 degrees (through Montana and then to Seattle) OAT 90F
Trip 4 AMZ ATF Idaho to Port Angeles WA.............trans temp average 155 degrees (through Oregon and dead mans pass) OAT94F
Trip 5 AMZ ATF Idaho to Port Angleles WA............trans temp average 145 degrees (through Oregon and dead mans pass) OAT 50F
Trip 6 AMZ ATF Idaho to Port Angeles WA.............trans temp average 138 degrees (through Oregon and then up I 5 to Seattle) OAT 48F

I keep these records and have for years............don't sell or advise Amzoil................don't care if YOU think I am wrong....................here are what the numbers come out at???? Whatever.

WHY is it that if something you post dosen't follow the "course of NORMAL" these responses come.

SouthernNights
03-13-2010, 07:50 PM
Not sure what you mean by buit in air conditioning but here are the specs:

Trip 1 FORD ATF Idaho to Port Angeles WA ..........trans temp average 197 degrees (through Oregon and dead mans pass) OAT 88 F
Trip 2 FORD ATF Idaho to Port Angeles WA...........trans temp average 188 degrees (through Oregon and then up I 5 to Seattle) OAT 55F
Trip 3 FORD ATF Idaho to Port Angeles WA...........trans temp average 200 degrees (through Montana and then to Seattle) OAT 90F
Trip 4 AMZ ATF Idaho to Port Angeles WA.............trans temp average 155 degrees (through Oregon and dead mans pass) OAT94F
Trip 5 AMZ ATF Idaho to Port Angleles WA............trans temp average 145 degrees (through Oregon and dead mans pass) OAT 50F
Trip 6 AMZ ATF Idaho to Port Angeles WA.............trans temp average 138 degrees (through Oregon and then up I 5 to Seattle) OAT 48F

I keep these records and have for years............don't sell or advise Amzoil................don't care if YOU think I am wrong....................here are what the numbers come out at???? Whatever.

WHY is it that if something you post dosen't follow the "course of NORMAL" these responses come.

I admire your record keeping. I assume that between trip 3 and 4 is where the Amsoil replaced a petroleum based product?

Another advantage of syntectics is that they transfer heat better than petroleum based products. I can understand the temp difference on trip 5 and 6. Ambient temp was much lower. Trip 4 is pretty remarkable though.

lwmcguir
03-14-2010, 08:22 AM
Mercon V is synthetic oil. Our temps seem to be fine running it. Would be curious if anyone else has seen the change.