I just purchased a 97 2500 with a 6.5 TD. It has a Banks transmission temparture gauge mounted about half way up the drivers side pillar post. I'm assuming it is something the previous owner added. My question is, the gauge has not indicated a temp yet. It's lowest range is 140 F and that is where the needle sits all the time. It is cold here (day time highs in the twenties) and I haven't towed with the truck yet. With no load on the truck and with these cold temps will the the transmission fluid reach 140 F or do I have a problem with the gauge? If it should be reading something would anyone out there know where the sensor might be attached so that I can check it out? Thanks.

Hard to say in the winter. The later models had an auxillary tranny cooler that may keep it from acqiuring any heat build up in the cold.

Is there also an aux cooler in addition to factory one ???, I added one to mine for heavy tow, thermostat controlled fan also. In winter months I rarely break 140 maybe on extended run I get to 150-160 running empty, in summer 180 is about normal, my remote cooler fan comes on at 170, also do you have any idea what you are monitoring pan temp???

Thanks for the replies. This truck had been used to pull a 5'th wheel trailor, that's also what I am going to use it for. I'll check to see if it has an additional transmission cooler. I'm pretty sure that it has a factory one since this truck was setup to tow. So even if just has the factory cooler it sounds like the transmission fluid might not get warm enough to registor till the warmer weather arrives. If we get some warm weather I may investigate further and try to find where they mounted the sensor, I was thinking they may attach it to the inlet or outlet of the cooler, but I'll also have a look at the pan. Thanks

Jcol, as stated by Turbine Doc, that tranny runs about 150 empty in warmer weather and thats after about 15+ minutes of driving. My guage starts at 100 so its a bit easier to see the change in temp early on. But right now its just under 0*F outside so the tranny tops at 130 or so. This is with the factory tranny cooler only. You will see your guage read when you start towing trailer.

As stated above tranny guage of that range will not show a reading in the winter while just doing normal driving. If you want to check the guage out before towing to be sure it works remove the sending unit from the trans and put it in hot water and watch the guage. You will have to attach a clip lead from the sending unit to the frame of the truck to complete the electrical circuit while testing the sendin unit.

There's a core in the radiator and in 95 or 96 they added an aux core on the HD on the passide infront of the radiator and condensor.

I wasn't sure how the aux cooler was plumbed from the factory, but I was told to put them on the before the cooler in the radiator. Reason being that in the winter the radiator 'cooler' actually needs to warm the tranny fluid to allow it to run warm and avoid failures associated with running it too cold. That being said, I would expect to see it warm up regardless of the time of year. Any thoughts?

The factory aux cooler is in front of the radiator, so it must not be that big an issue, I don't know if there is such a thing as too cool for tranny, since I did not know I put a thermostat on my electric fan operated remote cooler under the bed. It is set to come on at 170F pan return temp

When I start my truck not plugged in and it's near 32*F(hotel didn't have diesel plugs), the tranny takes longer than the engine to warm, about 15 min and it's still sluggish till you've run it through the gears once with the temps all the way up to operating temp. I don't have the aux cooler but the '96 my dad has does. I mounted the driver for the IP on it's bracket.

Well I am still kicking this one around a little, and I need to pull the trigger soon before I head back out to Glamis. :grd:I found that quite a few people are using the Tru-Cool Transmission coolers. I checked out the tru-Cool Sight and found two Good cooling cores. PN LPD4590 11x11x1.5 GVW 28000 and LPD4739 8.5x22x1.25 GVW rating 40000, I like the idea of keeping the Oil while towing around 180, and a fan assisted under the body seems like a good option, however the drawback is all the mud and stuff clogging it up. The other side of the coin seems to be mounting it between the fan radiator inside the fan shround. The only drawback to this is not being able to closely regulate the temperature at which the oil gets cooled. The other drawback is how to mount the cooler to the radiator. Anybody have any thoughts on this one? I believe that the kits come with a plastic push through type pin that goes through the radiator cooling fins and has a washer type fastner on the other side of the radiator. These type of fasteners kind of make me uneasy as they would not seperate the radiator and transmission coolers, thereby having the potential to rub holes in each other. Has anybody found any problems with the coolers rubbing yet? Any spatial problems with the fan clutch yet? Any noticable loss of cooling effiency of the radiator by having the transmission cooler next to it. Does anybody have any idea how many CFM the fan blows without the fan clutch engaged, from idle on up???? Lost of questions lots of food for thought!!!!!! Those darn dunes !!!!! Talk about and expensive addiction!!!!!:muahaha:

Several thoughts.
Mounting the cooler on the inboard side of the radiator will not provide much cooling because of the temperature of the air flowing off the radiator. The plastic pins supplied with the kits are intended to mount the cooler forward of the AC condenser coil, however there is a problem with that idea. Most manufactures suggest at least 1 in of seperation between cooling coils and the pin mound does not ptrovide this seperation.
As far as mounting it cooler under the truck. Unless you go Mudding on the weekends dirt build up should not be a problem. My cooler has been mounded under the rear seat for the last 4 or 5 years and I have never seen any indication of clogging. Just make sure you mount the face of the cooler parallal to the ground even though you first thought would be to mount the face directly into the trailing air flow coming under the truck. I am assuming the cooler comes with a thermostat to control the fan and the manufacture most likely stated in the direction that the fan will come on at about 180. If you look at the stat it may be market 165 and yu can get the fan to come on at about that temperature if you insolate the thermostat housing and cause it to see oil temperature rather than a combination of air and oil temperatures. I have removed the trans cooling line from the radiator and if you do the same you will soon notice the operating temperature of the trans if a function of outside temperature. As outside temperatures drop, below 30 degrees, the fan will not come on and the opeerating temperature of the trans will track outside temperatures. My trans runs at 100 degrees when the outside temperature is 0.
With this setup my trans runs at 150, with the convertor locked, while towing in the summer.

Howie: will the TCC still lock up at 100Degrees, Thought the Radiator Cooling/heating was for extreme cold, to get transmission up to temp, and to lock TCC.

Tryed the Radiator bypass, but without Cooling fan, in town, will run to hot in Florida.

In the dead of winter my convertor will not lock for the first 1 or 2 miles, but this is a very small price for the rest of the year better temperatures.
I look at the radiator oil cooling system as maintaining higher than desired temperatures 99% of the time, 180 degrees is not a great coolong source. It was just a cheap way for Detroit to get cooling.