06 Ram (5.9) auto trans cooler and heat??

[ivbinconned]

Just finished a 8500 K trip and noticed when ever we had little wind coming in the front end this tranny heats up. Highway speeds and warm weather no problem. Cold outside temps and slow lugging tyranny temps rises to 220 to 228 degrees.
Tranny cooler is clean and is not leaking (a tranny shop tells me they are prone to cracking).

Its as if the fan is not cutting in to pull enough air through to cool the tranny oil and yet the engine temp rises very little!!??

Is there no signal from tranny oil to kick in the clutch??

[ivbinconned]

Its been a while so don't know if any of you will see this post. It has occurred to me that there is such a wide gap (2 inches plus) between the inter cooler and rad on these trucks that a great deal of air can be sucked (path of least resistance)in over the top of the AC condenser, intercooler and transmission cooler and then on through the rad!!??

I remember having cars where every bit of air was forced through all coolers into the engine compartment because they had gaskets/seals around the edges.

[ib516]

45Ricochet wrote:
LOL
I remember that! Trans temp did better than rotors and pads.

You mean they're NOT supposed to smoke like a wet campfire? :W

[45Ricochet]

LOL
I remember that! Trans temp did better than rotors and pads.

[ib516]

ivbinconned wrote:
I saw this it was 20 below and I pulled the trailer up a steep incline perhaps an eight of a mile on packed snow and ice with chains on and tran in drive. But going very slow.

The 48RE doesn't lock the converter in 1st gear, so it builds a lot of heat when you are going slow. I wouldn't worry about those temps.

I pulled my 12k RV up Utah mountain grades in 100*F heat, and into a headwind and never got the trans too hot. The engine was up to this temp though....

[boogie_4wheel]

ivbinconned wrote:
I pulled the trailer up a steep incline perhaps an eight of a mile on packed snow and ice with chains on and tran in drive. But going very slow.

I did a few miles up some switchbacks in the late fall. It was in the 20's outside (not near as cold at you). My speed was around 20mph, and my trans hit 225 via OBD port. That slow of speed just doesn't get the airflow across the front cooler.

I haven't been concerned with the operation of the trans cooler, but there might be enough room for a slim electric fan to be mounted between the grille and cooler stack, but it is pretty tight up front. Another option would be to get a universal cooler with a cooling fan mounted to it (look at B&M). I wouldn't worry about it at all if this was a one time thing but if you frequent a steep climb at those speeds, a forced air cooler you might benefit from.

If the road is slick, drop it in 4-low, and then lock it in 2nd gear (or 3rd and T/H) and you can still get the TC to lock but at a much slower speed because of being in low range.

[ivbinconned]

The temp reading I see is from the Edge gauge set. The first time I saw this it was 20 below and I pulled the trailer up a steep incline perhaps an eight of a mile on packed snow and ice with chains on and tran in drive. But going very slow.

Coolers all look very clean. The truck has always had a window screen in front of them all which I took off at the first sign of the temp rising going through a vally with a 60 K speed zone going up the other side.

[BenK]

What is the frontal area and shape of both TV and trailer?

How much head wind?...20MPH more? 10MPH more? 25MPH more?

Do you have TH?

Kicks out of OD to be in lower gear ? Did it unlock the TC clutch ?

[thomasmnile]

ScottG wrote:

If it has failed then buy a new one ONLY FROM DODGE! None of the aftermarket units work well in our trucks and are nothing but headaches.

X2 on the OEM fan clutch. Just had the one in my '05 replaced. $438 from Mopar plus shop's labor, but the shop that works on the truck warrants his work for one year/12000 miles. He told me he won't do that with aftermarket parts because the reliability of aftermarket stuff is all over the map these days.

[ScottG]

228 trans fluid is nothing to be concerned about and the ECM will not turn the fan on for that level of trans temp.

[boogie_4wheel]

ivbinconned wrote:
...Cold outside temps and slow lugging tyranny temps rises to 220 to 228 degrees.

When going slow, manually select 2nd gear. This will cause the torque convertor to lock when you exceed 25mph (assuming 3.73 axle). If you leave it in drive, the TC doesn't lock until the trans is in 3rd and above 35mph when T/H is enabled.

There is also a possibility that the thermostat in the front cooler is gunked up and is reducing flow through the cooler (so it is partially stuck in the bypass position), and that could also cause warmer fluid temps.

[ScottG]

The fan's action is both thermal and electrically controlled. The fan can engage itself if it feels enough heat or the ECM can engage it.
Acceptable levels with modern fluid are much higher than they once were. I suspect the temps were not all that alarming to the truck itself.

[ib516]

The fan clutch's engagement in your truck is electronically controlled by the ECM. Hot trans temps will cause it to engage. Try looking in between the stack of coolers (it's hard to see so use a flashlight, even during daylight), and see if there is any dirt, leaves, or debris in there.

[ScottG]

The clutch should kick in if there's enough heat going through the radiator or if the eng gets hot enough. The ECM will kick out OD if the trans gets too hot (or even if it's too cold but that's another subject). Although it was not really that hot according to Dodge's numbers depending on where your taking the reading.
Maybe your clutch fan is trying to kick in but has failed. You might check for codes by turning the key on 3 times within 5 seconds and watching the odo for a code.
If it has failed then buy a new one ONLY FROM DODGE! None of the aftermarket units work well in our trucks and are nothing but headaches.
BTW, where are you taking the temp reading from?