Trans temp
05-21-2010, 04:21 PM
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Trans temp
My trans temp got to 200 degrees today is that too much. I was towing maybe 6,000 pounds in traffic it cooled off when i started to get rolling again.
05-21-2010, 04:42 PM
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http://www.pdrdiesel.com/oldsite/TempChart.htm
It seems like from whatI have read on various posts that running unloaded usually reads between 140-180. This is reading from the "hot line". Pulling hard will be between 170 and 220 with 220 being the highest one should go. If you are reading the temp from the pan or the "cool line" you will not get a true read which could be bad for the tranny.
Like I said this is just what I have read. I'm sure someone with "real world" experience will chime in soon.
It seems like from whatI have read on various posts that running unloaded usually reads between 140-180. This is reading from the "hot line". Pulling hard will be between 170 and 220 with 220 being the highest one should go. If you are reading the temp from the pan or the "cool line" you will not get a true read which could be bad for the tranny.
Like I said this is just what I have read. I'm sure someone with "real world" experience will chime in soon.
05-21-2010, 07:50 PM
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My sensor is in the hot line. I am betting the heat is comming from a stock slipping convertor. I have a goerend and I am having the trans rebuilt next week and I just dont want to melt something between now and then.
05-24-2010, 08:16 AM
#7
So it seems. My truck is an 04 so it might be a little different than yours. I also have a Georend. I challenge all to install an inline sensor at the TC exit line like the Diese lManor or Mass Diesel type. You can make your own by cutting the line and installing a suitable "T" fitting. Do not use a clamp-on sensor fitting. They can reduce the reading by 20-30 degrees. Some have said the inline sensor will restrict flow. Not true as the sensor does not protrude into the tube but does make direct contact with the fluid. Reveal your findings.
You will see 220-230 around town with the TC not getting into overdrive. Once you lockup you will see the temp drop quickly to below 190 and average around 160 on the highway. These numbers are unloaded. Imagine what you will get with a 10,000lb trailer on hilly backroads. It will scare you.
Apparently the ATF+4 synthetic fluid is up to the task. I have a Derale thermostatically controlled cooler on mine. I'm also going to install the "switch" to force lockup when I know I'm doing something that will take it over 230 for a longer period of time.
Also remember this is the highest temperature the trans sees and it is exiting the transmission on the way to the coolers. So in reality the incoming fluid that the trans sees is already cooled. I may install another sensor at the incoming line to read the difference.
Read the last paragraph of this...
http://www.dieseltrans.com/phpBB/viewtopic.php?t=558
You will see 220-230 around town with the TC not getting into overdrive. Once you lockup you will see the temp drop quickly to below 190 and average around 160 on the highway. These numbers are unloaded. Imagine what you will get with a 10,000lb trailer on hilly backroads. It will scare you.
Apparently the ATF+4 synthetic fluid is up to the task. I have a Derale thermostatically controlled cooler on mine. I'm also going to install the "switch" to force lockup when I know I'm doing something that will take it over 230 for a longer period of time.
Also remember this is the highest temperature the trans sees and it is exiting the transmission on the way to the coolers. So in reality the incoming fluid that the trans sees is already cooled. I may install another sensor at the incoming line to read the difference.
Read the last paragraph of this...
http://www.dieseltrans.com/phpBB/viewtopic.php?t=558
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05-24-2010, 03:31 PM
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This has been a controversial topic ever since i can remember. It makes sense to monitor the output of the trans to make sure everything is working properly and so you can stop before total destruction. It also makes sense to monitor pan temperature to make sure your coolers are working well. Also it would be nice to know that your putting cool fluid into the trans and see how much your converter is raising temperatures. Seems that you really need both to keep a handle on the entire transmission system.
05-24-2010, 09:33 PM
#9
It's good to know exactly how hot the fluid gets so you at least know if you are cooking it. The problem is lack of data on what these newer synthetics can handle and for how long.
Here's an interesting article..
http://www.autoshop101.com/forms/AT06.pdf
Here's an interesting article..
http://www.autoshop101.com/forms/AT06.pdf
05-24-2010, 10:01 PM
#10
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The A518 trans used in the 91.5 and later 1st gens has a temperature sensor in the exiting fluid line (before the fluid/fluid heat exchanger). By design, if you overheat the fluid (indicating an overload condidtion), the trans will drop out of OD.
IMO, while it's nice to see what the fluid is doing coming out of the non lock-up converter, I feel that read in the pan is a better indicator of what's actually going on in the trans as at that point, returning cool fluid has passed over the bearings and clutch-pacs.
IMO, while it's nice to see what the fluid is doing coming out of the non lock-up converter, I feel that read in the pan is a better indicator of what's actually going on in the trans as at that point, returning cool fluid has passed over the bearings and clutch-pacs.
05-24-2010, 11:00 PM
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This is a big issue for me because my truck is going to be used to move up to around 20,000 pounds before I'm able to get this medium duty 5 speed put in.
It's a 1990 / 727. A couple years ago I had the trans and converter completely flushed and generally inspected and the verdict from the shop was that there was a little bit of metal in the pan but about what you'd expect from 320,000+ miles. Since then I still haven't actually worked it, only driven it empty and not all that much. It seems to shift just fine (although the shifter linkage itself won't let me put it into "1", which I need to fix...)
Anyway, 20k is probably beyond the limit of what a 727 is ever supposed to do. From what I've absorbed on these forums about them and their performance I'm not real worried about it breaking as long as I don't let it get hot or try to drive crazy.
Because it's not set up as a regular pickup I can put pretty much any size cooler anywhere. I've got a used 1st gen AC condenser that I'm probably never going to actually use for that purpose, is it possible to tap the in and outlets and use it as a trans cooler?
I'm also wondering if there's any reliable way to put more than one temp sender on the same gauge, like if I could flip a switch from the temp coming out of the TC to the temp coming out of the pan.
It's a 1990 / 727. A couple years ago I had the trans and converter completely flushed and generally inspected and the verdict from the shop was that there was a little bit of metal in the pan but about what you'd expect from 320,000+ miles. Since then I still haven't actually worked it, only driven it empty and not all that much. It seems to shift just fine (although the shifter linkage itself won't let me put it into "1", which I need to fix...)
Anyway, 20k is probably beyond the limit of what a 727 is ever supposed to do. From what I've absorbed on these forums about them and their performance I'm not real worried about it breaking as long as I don't let it get hot or try to drive crazy.
Because it's not set up as a regular pickup I can put pretty much any size cooler anywhere. I've got a used 1st gen AC condenser that I'm probably never going to actually use for that purpose, is it possible to tap the in and outlets and use it as a trans cooler?
I'm also wondering if there's any reliable way to put more than one temp sender on the same gauge, like if I could flip a switch from the temp coming out of the TC to the temp coming out of the pan.
05-24-2010, 11:21 PM
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Anyway, 20k is probably beyond the limit of what a 727 is ever supposed to do. From what I've absorbed on these forums about them and their performance I'm not real worried about it breaking as long as I don't let it get hot or try to drive crazy.
I'm also wondering if there's any reliable way to put more than one temp sender on the same gauge, like if I could flip a switch from the temp coming out of the TC to the temp coming out of the pan.
I'm also wondering if there's any reliable way to put more than one temp sender on the same gauge, like if I could flip a switch from the temp coming out of the TC to the temp coming out of the pan.
Also i would suggest to anyone to bring back the band adjustments and turn up the pressure screw on the valve body.
Read this thread, it explains everything perfectly.
Adjusting your bands, shift points and line pressure
05-25-2010, 12:00 AM
#13
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Onemoparnut: I have a 92, it warms up to about 190 and seems to stay around there unloaded. With a full bed, I don't worry until 220 - then I kick out of OD or let off the pedal or both.
My basic rule lately: If I'm going uphill loaded, I'm in 3rd.
My basic rule lately: If I'm going uphill loaded, I'm in 3rd.
05-25-2010, 04:30 AM
#14
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This is a big issue for me because my truck is going to be used to move up to around 20,000 pounds before I'm able to get this medium duty 5 speed put in.
It's a 1990 / 727. A couple years ago I had the trans and converter completely flushed and generally inspected and the verdict from the shop was that there was a little bit of metal in the pan but about what you'd expect from 320,000+ miles. Since then I still haven't actually worked it, only driven it empty and not all that much. It seems to shift just fine (although the shifter linkage itself won't let me put it into "1", which I need to fix...)
Anyway, 20k is probably beyond the limit of what a 727 is ever supposed to do. From what I've absorbed on these forums about them and their performance I'm not real worried about it breaking as long as I don't let it get hot or try to drive crazy.
Because it's not set up as a regular pickup I can put pretty much any size cooler anywhere. I've got a used 1st gen AC condenser that I'm probably never going to actually use for that purpose, is it possible to tap the in and outlets and use it as a trans cooler?
Using an A/C condenser might be too much restriction in the circuit, you need a cooler with at least 1/2" inlet and outlet lines and a Fin & Plate design would be best choice.
I'm also wondering if there's any reliable way to put more than one temp sender on the same gauge, like if I could flip a switch from the temp coming out of the TC to the temp coming out of the pan.
It's a 1990 / 727. A couple years ago I had the trans and converter completely flushed and generally inspected and the verdict from the shop was that there was a little bit of metal in the pan but about what you'd expect from 320,000+ miles. Since then I still haven't actually worked it, only driven it empty and not all that much. It seems to shift just fine (although the shifter linkage itself won't let me put it into "1", which I need to fix...)
Anyway, 20k is probably beyond the limit of what a 727 is ever supposed to do. From what I've absorbed on these forums about them and their performance I'm not real worried about it breaking as long as I don't let it get hot or try to drive crazy.
Because it's not set up as a regular pickup I can put pretty much any size cooler anywhere. I've got a used 1st gen AC condenser that I'm probably never going to actually use for that purpose, is it possible to tap the in and outlets and use it as a trans cooler?
Using an A/C condenser might be too much restriction in the circuit, you need a cooler with at least 1/2" inlet and outlet lines and a Fin & Plate design would be best choice.
I'm also wondering if there's any reliable way to put more than one temp sender on the same gauge, like if I could flip a switch from the temp coming out of the TC to the temp coming out of the pan.
Low temperature senders are resistance units.
You can read as many as you want with any single gauge, you can switch the outputs of the senders using a good quality toggle or rotary switch with the common or wiper lead going to the gauge sender terminal.
Or you could simply use a dual temperature gauge.
https://www.genosgarage.com/prodinfo...mber=WM-DUALTP
http://www.spatechnique.com/product_...ils.cfm?id=374
Jim
06-01-2010, 04:22 PM
#15
On a hot day no load... my trans at the hot line today was hovering around 220 degrees at a traffic light stopped. The light was a longer one. The temp didn't rise or fall. When I get moving and it locks up the temp drops to 190 in about 30 seconds. Crusing the highway I'm 160. I read in my latest TDR publication that Chrysler says it can reach 230 at which point you should take action to reduce the heat. That is based on the newer models that have a trans temp gauge. Does anybody know where Chrysler gets it temp reading from on the newer trucks that have gauges?