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Discussion Starter · #1 ·
I have been having some heat problems with my 47re. My trans has a Mag Hytec deep pan and I recently replaced my stock cooler with an upgraded Mishimoto factory replacement cooler and it definitely helps but it can still get out of control when it gets over 90 degrees outside. When I drive around town I keep overdrive off and it helps some but It’s not often I can get up to speed to hit lockup.
I was looking at installing a lockup switch and what I need. I heard the later gen 2 trucks will throw a code with a switch, is there anyway I can get around that? What is the best and most cost effective way to do it?
Thanks in advance!
-Nicholas
 

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I had a lockup switch and never got a code. It will aid a little in temps. Have you done a trans service recently? Do you still have your heat exchanger?
 

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Discussion Starter · #3 ·
I had a lockup switch and never got a code. It will aid a little in temps. Have you done a trans service recently? Do you still have your heat exchanger?
I just serviced the truck last weekend dropped the pan, new Valvoline Atf+4 New gasket and new filter. I also installed a mishimoto upgraded cooler and the power driven diesel cooler line kit cause the old ones were leaking. I do still have my heat exchanger. Not really sure why the trans still gets hot it seems to have most of the cooling goodies!
How did you have your lockup switch rigged and what year of truck?
 

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My 99 I what I had was just a splice into the tcc wire, ran it to a switch, and ran the other wire from the switch to a ground and bada bing I had a lock up switch never had a check engine light or limp mode. My current 07 I have the same concept, but I have a 33 ohm resister in the wire from the tcc wire to the switch to prevent a code.
 

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Discussion Starter · #5 ·
My 99 I what I had was just a splice into the tcc wire, ran it to a switch, and ran the other wire from the switch to a ground and bada bing I had a lock up switch never had a check engine light or limp mode. My current 07 I have the same concept, but I have a 33 ohm resister in the wire from the tcc wire to the switch to prevent a code.
So you don’t think that my 02 will throw a code?
Could you tell me the characteristics, how it drove what gear it would lockup in?
 

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Either it is not going into OD pre lockup when it should or the temp sensor is not working right in the OD solenoid unit. Either way you probably need to replace the OD solenoid pair to solve problem. Stock set up should not be getting getting hot cruising around town 25-45 mph and 90-100 degrees outside. If it is staying in third without lockup too much it will get hot. Again solenoid problem.
 

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Discussion Starter · #7 ·
Either it is not going into OD pre lockup when it should or the temp sensor is not working right in the OD solenoid unit. Either way you probably need to replace the OD solenoid pair to solve problem. Stock set up should not be getting getting hot cruising around town 25-45 mph and 90-100 degrees outside. If it is staying in third without lockup too much it will get hot. Again solenoid problem.
So what is your definition on a stock setup?
IMHO I don’t think my truck is exactly stock

I have two temp readings on edge
JTFT which is my pan
TFT which the unit gets from the OBD port

when TFT is at 220 JTFT will be around 180

Does that sound right?
Do you think that oversized tires without gearing could be causing this?

where could I get my hands on a set of OD solenoids?
 

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A lock up switch is good but If your Temps are high just cruising around you have something else going on.
Has the trans temp light come on or do you have a guage to know it's hot?
Is the engine running normal Temps?
Easy thing to check is fluid in the elecronic connector going into the trans.Fluid in there causes all kinds of problems.
Please fill out your signature so it's easier for folks to help.
 

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Stock is stock and working properly, even with up graded parts but not required. Meaning shifting and locking up when it is supposed to. Most heats is due to flow in torque convertor from not shifting or locking up when it is supposed to. Wnen mine got hot in town it was the OD solenoids not shifting to od and not locking up..
 
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