What should the stock transmission fluid temp be when cruising?

I just got my gauge back from Westach that has had the pointer stuck since I installed it. I have the sensor on the transmission line, not in the pan so I know it will be a bit cooler there. Haven’t gotten around to installing the port in the pan yet.

Yesterday it was 45 degrees out and the temps indicated from 100 to 110-not towing anything.

She rolled over 114,000 miles and y’all have me thinking my transmission might be getting short in the tooth.

3 minutes ago, notlimah said:

Most people on the forum say to monitor to hot return line.

 

Which is true. 

 

But if you ask @Dynamic he'll say monitor the pan temperature. 

 

Like even in my case on the 1996 Dodge Ram 1500. I didn't have the bung at the time of the rebuild or I would of had Jon put it in for me. So when I got the gauge I used ISSPro's clamp on sensor setup for the hot line for now. I want to take the time and have the bung put in the rear of the transmission pan where Jon marked it for me. It will read the very same temperature that the PCM reports. Remember the stock transmission temperature sensor is part of the governor pressure sensor which is once again inside the pan.

That’s what I was getting at when I said ‘everyone who works on these says...’

 

I’m not saying booking it up to the hot line is wrong. Just depends on what temp you wanna read. I personally see no point in knowing how hot the fluid is that’s going to be cooled. I want to know how hot it is before it’s being used. 

 

Just wanted to point out two different points of view from two different types of people.

I have my probe in the tranny case where the quadzilla says to put in in their manual. I plan on splicing it into the return line this summer, but right now with this cold it doesn't even register a temp. as the minimum is 100 F unless I got WOT for a stretch then it will come up to 105 but then back down to under 100F. 

1 hour ago, Youngblood24v said:

I have my probe in the tranny case where the quadzilla says to put in in their manual.

 

There is no port in the transmission where the fluid flows enough to be in any of those ports. Either put in in the pan or the return line. Personally, I'm going for the pan. I'm going to put the sensor down low in the pan so it doubles for a drain plug. 

I have a deep dish MagHytec pan, when I rebuild the tranny after the truck is finished I'll move the sensor into the port in the pan.  I need to have a new larger cooler installed behind my bumper as my heat exchanger was leaking coolant when I removed it   I won't be running the truck anymore in the winter so am not concerned with the fluid not warming up enough

 

Edited April 10, 20186 yr by Tom Robarts
double post

If you have any interest in running the stock-ish heat exchanger lemme know and I’ll dig through some links and find a company that builds new units.

Does anybody know if their is a significant difference between the Derale deep dish and the maghytec pan? Besides the $150 price difference of course ? 

Get a Goerend pan if anything. It’s not huge but still holds more then stock. Has built in bung for temp. Sloped interior so all fluid drains out of the 1in plug on the bottom. And it won’t break the bank.

I actually bought the whole new tranny line with a port built in.. IIRC Genos had them.

So I have my sensor on the hot tranny line going to the cooler

 

My tranny runs cool. as  they all should unless your out of lock up pulling a steep grade

 

 

I had my tranny rebuilt last fall in late Sept., my heat exchanger (on the side of the block) wasn't leaking, but it was really crusty, so I had the tranny shop eliminate it (cost prohibitive through the dealer to replace) and I went with a large cooler from O'Reilly's that was bolted to my bumper ... I went with a deep sump pan from LPW Racing Products-phone # 717-394-7432, I used a GlowShift temp gauge and the sensor is in the pan, I drove the truck up until Dec. when the ECM went out, I only towed a light load with it in that time frame, and the temp never went above 150, other then that, the temp would only climb above the base temp of 100 when I was idling, or in city traffic ... I'm now waiting on my ECM to come back from Auto Computer Specialist, and I'm going to re-route my grounds/B+ while I wait ..... When I was searching for a deep sump pan I found that LPW had pans that were built like the Maghytec's, but priced like the Derale's, and you could buy it with/without the pan being pre-drilled for a temp sensor (at the time a $10. option for pre-drilled) ...

Edited April 11, 20186 yr by PoppaSmurf

1 hour ago, PoppaSmurf said:

I had my tranny rebuilt last fall in late Sept., my heat exchanger (on the side of the block) wasn't leaking, but it was really crusty, so I had the tranny shop eliminate it (cost prohibitive through the dealer to replace) and I went with a large cooler from O'Reilly's that was bolted to my bumper ... I went with a deep sump pan from LPW Racing Products-phone # 717-394-7432, I used a GlowShift temp gauge and the sensor is in the pan, I drove the truck up until Dec. when the ECM went out, I only towed a light load with it in that time frame, and the temp never went above 150, other then that, the temp would only climb above the base temp of 100 when I was idling, or in city traffic ... I'm now waiting on my ECM to come back from Auto Computer Specialist, and I'm going to re-route my grounds/B+ while I wait ..... When I was searching for a deep sump pan I found that LPW had pans that were built like the Maghytec's, but priced like the Derale's, and you could buy it with/without the pan being pre-drilled for a temp sensor (at the time a $10. option for pre-drilled) ...

 

do you have any info on the added cooler you used on the front of the truck?

@Ed ke6bnl ..... 

Flex-A-Lite Flex-A-Fit Copper, Aluminum Oil Cooler 

Part #

 

45901

 

Line:

 

FLX
That cooler comes with a fan attached that I haven't hooked up yet, and probably never will ....

Edited April 11, 20186 yr by PoppaSmurf

The correct spot to measure fluid temp. is in the pan. The same place your factory sensor is on ALL 47res. I use the rule of 100* above ambient before getting nervous about trans temp. The fluid is good until a bit over 200*s F (exact number is escaping me). The difference between the derale pan and any of the cast aluminum pans is........the derale will not support the case from twisting forces like the cast aluminum pan will. 

I installed a B&M aluminum pan when I got my truck.  I don't think it holds any extra fluid, but it has cooling fins, a drain plug and a temperature port and was a heck of a lot cheaper than any other pans I looked at.  I was wondering where the factory temp sensor was today.  I had to do a lot of towing and noticed the Edge monitor was showing about 30* higher than my GS gauge which is in the pan. 

How come you got the two different bolts in the side? 

4 hours ago, notlimah said:

How come you got the two different bolts in the side? 

 

The pan was meant to work on several different variations of this transmission.  I guess one version had a bracket that mounted there so they gave you 2 different bolts for that, but didn't give you 2 extra of the other ones if you didn't need the bracket.

Edited April 12, 20186 yr by Sycostang67

Another option for eryone too.

 

https://www.ebay.com/itm/727-A518-46RE-DOUBLE-DEEP-TRANSMISSION-PAN-DODGE-RAM-DIESEL-FINNED-ALUMINUM/111856143214?hash=item1a0b254b6e:g:5xcAAOSwwvZZQr04&vxp=mtr

@jlbayes, that's the same company that I posted the info for above, the only issue I had with the whole transaction was that his website said that you may have to sign for the package, and it's not a "may" it's a "definite", and at least at the time of my purchase it could only be sent to the billing address, I was working at the time of delivery, long story, short, I was able through Fed-X to change that arrangement, and had it sent to the tranny shop doing the work, and they signed for it..... Other then that hic-up it's a great deal for an extra capacity finned pan .....
http://www.lpwracing.com 

 

Edited April 12, 20186 yr by PoppaSmurf

2 hours ago, PoppaSmurf said:

@jlbayes, that's the same company that I posted the info for above, the only issue I had with the whole transaction was that his website said that you may have to sign for the package, and it's not a "may" it's a "definite", and at least at the time of my purchase it could only be sent to the billing address, I was working at the time of delivery, long story, short, I was able through Fed-X to change that arrangement, and had it sent to the tranny shop doing the work, and they signed for it..... Other then that hic-up it's a great deal for an extra capacity finned pan .....
http://www.lpwracing.com 

 

 

Sorry I had skipped right across your post. I ordered mine through ebay with no troubles. 

A lot of good info here...

 

I, personally, consider anywhere from about 150-180 degrees F to be an ideal operating temperature for an automatic transmission. Many run cooler than this, which is really no problem. Some run hotter than this, which is not a big problem (to a point, obviously), as long as the cooling system is able to bring it back down when the "heat-inducing" conditions are removed. When you're working the transmission, it's going to make heat. There's no getting around it. As long as that heat can be managed, life is good...

 

I am a big proponent of leaving the OEM heat exchanger in place. It is technically called the "torque converter cooler" by Chrysler, and that's exactly what it is. When you're working your converter hard, the fluid temps coming out of it can be downright scary! The heat exchanger does a fantastic job of knocking that temp down to where the air-to-fluid cooler (auxiliary cooler) can manage it effectively. Does the heat exchanger heat cool fluid? Yeah, some... But not enough to worry about, and the benefits when the fluid is hotter than the coolant cannot be overstated.

 

I highly recommend placing the temperature sender in the pan, as many have mentioned. The Low/Reverse servo pressure tap is where it ends up a lot of times, but there's not really any fluid circulating there. It just kind of gives you a reading of the temperature of the case right there. Better than nothing, yes, but not ideal. Plus, if you put a billet servo piston in the Low/Reverse, the sender will interfere with its operation.

 

I have found, through a bunch of recent 3rd Gen testing recently, that the OEM temp sensor in the transducer seems to read high...sometimes by quite a bit. If you have a scanner or monitor that is simply pulling transmission temp information off of the data stream, I would verify its accuracy before I got too worked up about anything. A recent customer was concerned about his 190-200 degree indicated operating temperature (Edge CTS2). Testing this info against a known good gauge (and also an infrared heat gun) showed that it was reading about 25-30 degrees high. A new transducer brought things much more in line, but it still read high. Take it with a grain of salt until you verify its accuracy.

 

Running a deep pan is never a bad idea, although don't look to it to solve an overheating issue. More fluid is a bigger heat sink, and does tend to lower operating temperatures with all other conditions being equal. But it you have a heat issue, more fluid will have a small effect on things. The main reason that I like to run an aftermarket pan is to strengthen the case, as @jlbayes mentioned. The bottom of the case on a 46/47/48 RE transmission is wide open, and case flex can be a pretty big deal when the torque numbers reach the stratosphere. A good aluminum pan really helps...probably more than you would think. There are many good pans on the market. I have used Goerend, Mag-Hytek, LPW, B&M, and probably others as well. All are good quality pieces, and do their job well. I will say that I have never been very impressed with Derale pans. No offense to those who have them, but they are really quite flimsy when compared to an OEM pan, and offer no additional case rigidity, as was mentioned. I have been through some ugly wars with Derale pans trying keep them from leaking as well.

Edited April 14, 20186 yr by Dynamic