I have finished my tranny temp gauge install. The sender is in the pan. I checked the calibration in boiling water against a known accurate thermometer. It is within a couple degrees. After install, I checked it against an infrared temp gun aimed at the tranny pan. The gauge is within a couple degrees.

Autometer electric gauge
Short Sweep 100 to 250 F
Accuracy:
Within a needle width at 100 F
Right on at 180 F
Within half a needle width at 212 F
Sender in Transmission pan

Here is what I am seeing for temps so far:

Outside air temp: 50 F
Speed 35 mph for 20 minutes
Mostly Level Road
Overdrive Off
Tranny Temp 110 F

Outside Air Temp 53 F
Speed 65 mph for 20 Minutes
Mostly Level Interstate
Overdrive On
Tranny Temp 115 F

Outside air temp 70 F
Speed 45 mph for 1 hour
Small Hills
Overdrive Off
Tranny Temp 130 F

Outside Air Temp 73 F
Speed 20 mph for 10 Munutes
Dirt roads 4wd Hi
Level Road
Tranny Temp 130 F

Outside Ait Temp 73 F
Speed 5-10 mph for 10 minutes
Dirt Roads, Wash-outs, Rocky, Slight uphill
4wd Low
Tranny Temp 150

Outside Air Temp 73 F
Speed 1-5 mph for 10 minutes
Dirt Roads, Wash-outs, Very Rocky, Steeper uphill
4wd Low
Tranny Temp 180 F

Outside Air Temp 73
Return trip down same roads
Tranny Temp 130 F

Outside Air Temp 93 F
Speed 45 mph
Level Roads, in and out of town
Overdrive on and off
Tranny Temp 145 F

Having the airconditioner on and off made no difference in engine or tranny temp.
I will be noting the transmission temp if I hear the mysterious ding some people are reporting. I have heard it twice prior to gauge installation.
I will also keep this post up to date with the highest temp readings I see along with the conditions which brought them about.
For an explanation as to why I put the sender in the pan, go here https://www.jk-forum.com/forums/show...t=39769&page=2
Scroll down to post #17.

 

Your temps don't seem to be as high as some others have reported (which is a good thing).

 

You should do a write-up of the pan install.

 

So how about 4lo for a longer period of time on a constant hill climb? That is when my not so mysterious ding chimes in! I'm glad to see that you did the temps like I was planning instead of the assumtion game.. Thanks and I will be watching for further updates.

Oh yeah what gear ratio do you have and tire size?

 

It's in the works.
I registerd with the "my.project-jk" gallery, but have not received the e-mail to complete the registration. Therefore, I cannot upload pictures yet.

4.10's and 32" tires.

 

Thanks mine is a tad different with 35's and the same RUBI ratio

 

You didn't say, do you have a transmission cooler installed?

 

No supplemental cooler. Only the factory cooler.

 

I would be inclined to think the oil pan install would give lower readings due to the oil in the pan is not in the direct flow of the transmission lines. I toyed with the idea of a pan install for my sensor, but declined to do so. The factory sending unit is a good ways above the pan - it is probably mounted in an optimal spot for reading the temperature. I believe it is located at about the same level as the cooler lines are on the transmission. I dont think your readings are giving you a very good indication of the operating temperature of the transmission.

 

The highlighted words above are incorrect. The factory sensor projects down into the sump fluid. Here is a quote from the factory service manual:
"The transmission temperature sensor (2) is located in the transmission range sensor (1) and communicates transmission sump temperature to the TCM.
OPERATION
The transmission range sensor (TRS) has an integrated thermistor that the TCM uses to monitor the transmission's sump temperature. Since fluid temperature can affect transmission shift quality and convertor lock up, the TCM requires this information to determine which shift schedule to operate in. The TCM also monitors this temperature data so it can energize the vehicle cooling fan(s) when a transmission “overheat” condition exists. If the thermistor circuit fails, the TCM will revert to calculated oil temperature usage."




Did you read the following, linked in the first post of this thread?

This is what my research has revealed about trans temp probes located in the various points on the 42RLE transmission.
The following is what I have concluded based on my best effort to get the facts.

Line out to the cooler:
This will show temperature of fluid coming out of the trans, but it will be variable with short term spikes as the TC locks and unlocks. Short term temp spikes are normal and not detrimental to transmission fluid life. A probe in this location can lead to unnecessary anxiety.

Line from cooler to transmission:
This will show the fluid after cooling, and will be lower than what the pump picks up from the pan.

In one of the many pressure ports on the side of the transmission:
This will show temp of the fluid only when the particular circuit is in operation. You would have to choose which port to monitor. They are torque converter clutch on, torque converter clutch off, reverse, low/reverse, 2/4, underdrive, overdrive.

This brings us to the pan:
This will show temp of fluid the pump picks up and sends through the transmission. The sump is sort of a "dampener" for fluid temperatures. It reflects the steady state temperature of the fluid. Long term temp rise, which is what degrades the transmission and fluid, will show in the sump. As mentioned above, short spikes in temp as the fluid leaves the transmission are not a factor.
The transmission's factory temp sensor monitors the fluid in the sump. The normal programs in the tranny controller respond to sump fluid temperatures.
The troubleshooting charts and operational limits are based on sump temps.
Some brands of transmission temp gauges recommend an inline probe location IF installing it in the pan is not possible for some reason.
Several local transmission shops recommend the pan location. However, they say most people choose one of the inline locations for ease of installation.

Based on what I have learned, I will be installing the temp sensor in the pan.