Transmission temperature?

[silverram03]

Hey guys I did a search and couldn't find a definitive answer to my question. Anyway here go's, I have Isspro EV2's installed and my transmission temp is reading from the test port nearest the front on the transmission just after the bell housing on the passenger side. What kind of temps should I be expecting? currently I see about 130-140 on the highway and on really cold days it barely hits 120 and I see about 140-170 in town not towing. Are these temps safe? I also currently have my winter cover on with all flaps open.

 

[Brent P]

you will get a more accurate reading from the line going to the cooler Diesel Manor offers a replacement line that has a port for the probe. Temp wise I have been told that about 210 would be safe. Anything over that and the oil starts breaking down at a faster rate.

DieselManor - Dodge Generation 3 Cooler Line

 

[cerberusiam]

Can't tell whether any of those readings are good or bad as that location is a dead end port. All your reading there is heat soak in the transmissions and not fluid temp.

 

[silverram03]

Can't tell whether any of those readings are good or bad as that location is a dead end port. All your reading there is heat soak in the transmissions and not fluid temp.

I'm not sure its a dead end port as it has fluid at that port, I'm no transmission expert though. I came from an 03 with a NV5600 so its all new to me. When I ordered my gauges from diesel manor it was suggested I use this fitting for my temp readings. I see what your saying as far as the heat soak from the transmission case though.

 

[cerberusiam]

I'm not sure its a dead end port as it has fluid at that port, I'm no transmission expert though. I came from an 03 with a NV5600 so its all new to me. When I ordered my gauges from diesel manor it was suggested I use this fitting for my temp readings. I see what your saying as far as the heat soak from the transmission case.

Its a dead end port, no circulation. None of the test ports have circulated fluid at them as they are a pressure point. They will read whatever temp the trans has accumulated to that point irregardless of what fluid temp is.



It could be higher or lower depending on conditions. With the probe in the hot line and TC locked you will generaly be within 10-20 degrees of coolant temp, TC unlocked could be 190-260 depending on load, grade, etc.



In the pan 35-40 gegrees less than coolant temp is average under no load. It could go higher if you are pulling a load.



Once the engine is up to temp pan or hot line temps with TC locked are going to run 150-180 depending on ambient. Almost never will you see a temp less than 140 as that is the minimum operating temp for ATF+4.



Your posted temps do not indicate an issue. However, you can over temp the fluid and see the trans light on the dash before the temps in those ports indicate a problem. The real issue is unless you used an extension, which will cause even lower temps, the probe could hit the servos behind that plug and really mess things up. IIRC, that is the intermediate servo you have tapped and you really don't want to have fix the issues messing it up will cause.



You will be surprised what the temps says towing in stop and go traffic with the sloppy stock TC. That 140-170 could easily be 210-240 in fluid coupling.



I use the hot cooler line to see the absolute highest temp possible and down shift manually according to that temp and time it is there. The pan temps in lockup generaly run 10-15 degrees less than the hot line and my trans runs 10 degrees either side of 180 depending on ambient. When those temps go out of that range I know something is up and can take action.

 

[silverram03]

Thanks for the replies. cerberusiam I do have the extension from diesel manor so hitting the servos should not be an issue, I do appreciate the info about the test ports as I was wondering what was behind them. Once again thank you, now if I can only find that test port plug I removed so I can order the transmission line with the port in it. What exactly does the intermediate servo do?

Greg

 

[rscurtis]

It applies second gear. Personally, and I'm sure I'll take some heat on this (NPI), measuring the hot line to the cooler is like trying to measure the temperature of your house by measuring the water temperature coming out of your boiler- it shows only one part of the system that is subject to temperature fluctuations depending on the particular operating condition at that time. Measuring oil pan temperature gives the entire picture- you can see what is normal, and then see a trend if something is wrong. A temperature of 250 in the hot line could be perfectly normal for a short period of time- but if you exceed the time limit, you'll see it in the pan temperature.

 

[Yo Hoot]

So it would be interesting to have a sensor at both locations. I have one in the line. I would like to see both the line and the pan to see how fast the double deep Mag pan catches up to the line temp. I see 240 worst case not pulling but fluid coupling on hilly roads. Lockup cools it down fast.

 

[mtnram]

I opted against the modified line after considering leak potential and crafted up this heat sink that fits on the trans to cooler line

#ad

 

[Superglide]

Check this link out and see y-knot's explanation on page 1.

https://www.turbodieselregister.com...003-2007/129688-transmission-temperature.html



Also this link is to DTT.

Dieseltrans.com :: View topic - Transmission Temp Sensor Location

 

[Yo Hoot]

I opted against the modified line after considering leak potential and crafted up this heat sink that fits on the trans to cooler line

That works. I like the inline sensor better though. It's as direct a reading as you can get with the sensor in direct contact with the fluid. Clamp on will give you a slower less accurate reading. Genos Garage sells one.

As far as having leak potential. . I don't think it will ever leak. It's high quality fittings... dry as a bone. The real leak potential is the Chrysler rubber hose part at the bottom of that line.

#ad