Engine/Transmission (1994 - 1998) transmission temps

[milto]

what kind of temps do you see with an auto transmission.



city traffic(90 degree heat)

highway

underload(pulling,etc)



Thanks for any info

milt

 

[Dieselnerd]

Temps taken at hot line leaving transmission. Winter towing trailer, in lockup. on highway, 120 degrees. Same situation in hot weather over 90 degrees, 150 degrees. Traffic, not towing, stop and go, 150-175 degrees. Same with trailer shown in signature, 200-210 degrees. Parking trailer, hot weather, 230-240 degrees.

 

[DSutton]

I have only recently installed gauges, so my info is limited but here goes:



100-120 Empty

120-140 pulling a load (Total weight 16,500 pulling interstate grades of up to 6-7%)



Outside air temps are normally between 50-60

 

[Koa Man]

In hot line, air temps 80-90 degrees, I usually see around 140-150 normal driving. Towing at a GCVW of 18K about 180. Steep hills and backing up a trailer will easily push temps to 210-260. Since I tow daily and see temps go to 260 about once a week, I change my transmission fluid every other engine oil change, or about every 7000 miles.

 

[Johnny5]

Thanx for starting this topic and for the posts, was just gonna ask the same question since just cruising around I saw 135 (just installed my trans sender)and wondered what was typical.



Johnny5

 

[bmoeller]

Koa Man- Do you use syntetic ATF? That should help so you wouldn't need to change the oil so much. It handles heat alot better.



We started to use syntetic in the feederhouse reverser on the combine. It doesn't get burnt or turn brown anymore and still smells and looks like new after harvest. We just change it before each harvest.

 

[Koa Man]

I have been using Valvoline ATF+3. I may go to syn oil next time around... in about another 2500 miles. My fluid is still a very nice red color and not burnt when I do my changes. I just change it that often after I saw a fluid life expectancy chart for transmission fluids. My truck is 7 years old with 72000 miles, so changes are about once every 9 months or so.

 

[BillGotthelf]

Milto - you are going to get a range of temps from different people as there are many locations to instal temp sender. Dieselnerd had it right. Located in the cooler line going to the trans cooler is the best place. My 96 has it in the pan and the highest I have ever seen was 200. My 99 is in the cooler line out and I have seen 233. I run synthetic in both to take no chances.

 

[R-N-R]

How "durable" are the sending units? Will one withstand a drop from waist high to Home Depot's floor?



How long does it take for temps to rise at idle? With a few minutes of idle and a short drive in town my gauge (new) barely moved.



TIA,

Bill

 

[amsoilman]

my NEW 03' has 6-speed, but my old 94' had the AT. I also had the Mag-Hytec DDP on it with the temp sender in the pan. I had one gage that measured ALL fluid temps by the use of a rotary switch. On hot days TCC locked, Trans temp would run around 110-120 F. Rearend temp and engine oil temp would run around 175-180 F. It was very nteresting as the Differential and the engine temps were nearly always running the same temps as opposed to the transmission temps.

When TCC was unlocked such as backing in trailer, then the transmission temp would rise, but I never saw transmission temp go above 190 F. I did have synthetic ATF installed as well.



Wayne

amsoilman

 

[Koa Man]

Originally posted by Rock-N-Rammer

[B

How long does it take for temps to rise at idle? With a few minutes of idle and a short drive in town my gauge (new) barely moved.



TIA,

Bill [/B]

Where is your sender located? I don't think it will move much if at all on a short drive if located in the pan. My truck has the sender in the hot line and it will barely move above 140 with the truck unloaded and not climbing steep hills.

 

[bmoeller]

Hmmmm..... From these temps it looks like I may need to get a different gauge. The gauge I got is one that reads 140-320*(R9055). It is installed with exception to hooking up the sender and the 12v supply. Just got the new '95 cooler line yesterday finally. Should have it in tomorrow.

 

[R-N-R]

Koa Man,



I tapped the hot line (? drivers side front line that crosses to the passenger side and runs up to the heat/water exchange ?) on the vertical section "under" the exchanger, with a Jannetty manifold.



My gauge also starts at 140*.



Bill

 

[BillGotthelf]

Your gauge needs to start lower than 140. The trans may never see 140 with short trips in the winter. Towing a 13,000 lb fifth wheel from Fla to Conn 2 winters ago I never saw trans temps over 130 when outside air temp was below 50.

 

[R-N-R]

Dang, I hate it when that happens (new gauge)!



This Hewitt reads:

140 - 170 (yellow); 170 - 280 (Green); 280 - 320 (yellow/red)



Any idea what this might be designed for?



Bill

 

[bmoeller]

Originally posted by BillGotthelf

Your gauge needs to start lower than 140. The trans may never see 140 with short trips in the winter. Towing a 13,000 lb fifth wheel from Fla to Conn 2 winters ago I never saw trans temps over 130 when outside air temp was below 50.

Bummer. Have to order a different one. I wonder if DIS will trade? This one hasn't been used yet, just sitting in the pod. I'll have to call and find out.

 

[fortunate1]

Temps in MagHytec DD pan

I have bypassed the OEM cooler that sends the ATF thru the engine coolant (~185 deg F) and now cool the ATF only with air, so the ambient temp will affect how hot it gets. Cruising (loaded or not-doesn't matter), it's about ambient + 50 deg F in the summer; about ambient + 70 deg F in the winter. Usually that translates to about 110 to 150. Out of lockup (fluid coupling TC drive) the ATF will run a little hotter; stop & go will raise it to 150 to 200 (if I let it). I have 3 air-to-ATF coolers, with the largest one under the driver's side club cab; it also has a fan that I switch on when the temp reaches 150. I don't tow that much, but did tow about 350 miles yesterday-between 5000-6000 lbs I guess. That didn't affect the temps for me. It was cool outside, ~40 deg F. ATF temps were around 110-120 the whole trip since I towed in OD when I was on the highway (65-70 mph). On trips last summer, the truck was heavily loaded, but not towing, at 100 deg F+. ATF temps stayed at or slightly below 150.



In-pan temps are OK because that's the source for the ATF going into the transmission. Any given transmission is going to raise the ATF temp "X" degrees just by operating/shifting/etc. If the source is kept cool, then the outlet temps are going to be controlled. I know this from experience. If it weren't true, then my cooling system wouldn't be able to keep up with the rising ATF temps after it has run through the transmission; the pan temps would just keep steadily rising. Also the color, appearance, feel, and smell of the ATF after 20K miles (I change at 25K to 30K mi. ) is pretty much "like new". BTW, the transmission is stock except for a VB and the DD pan. I have changed the ATF very regularly, and am almost at 204K miles on the truck.