Trans temp questions (99 Suburban, 4L60e, using OBD2 app to read trans temp)

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redfishsc

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Main question is one for people who monitor their trans temps while driving. I'm using the Torque Pro app with a bluetooth OBD2 sensor, and it can read the trans temp on this truck. It "seems" to be fairly accurate, sufficient to make me grumble that they didn't put this on the damned dash board since the computer is reading it anyhow.

I towed a small camper about 600 miles this weekend, and the average highway temp seemed to stay about 150 (first day, outside temp 75) and then 172 (last day, outside temp 94). That sounds about right to me, but what do I know, lol. I saw it spike to 185 a few times, usually because of being stuck in traffic (an accident) or going down a business highway (lots of stoplights/hills).


This was towing in 4th gear (small camper) and I know for a fact the torque converter was locked up as it should be, because this same app tells me what RPM the torque converter is slipping. Also note, I swapped the rear gearing to 4.10 last December, which helps in towing in 4th.


How do those temps sound to you guys? Having never monitored trans temps before, all I know is the chatter I see on google searches.



Truck-- 99 Suburban, 210K miles. Probably original transmission, unless it was replaced before 135K when the prev owner bought it. Engine is stock 5.7. As said above, I swapped the rear gearing to 4.10, which has been an excellent upgrade.


The trans works fine, the only mods I've done to it is a pan with a drain plug, new filter, and two pan-dumps and refilled with Max-Life (Dex 6 spec). Old fluid was dark red.
 

Kran

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howd you get it to work on Torque Pro? i have that app and havent been able to get it to read...i have a 99 too. i added the GM PID set too.
 

redfishsc

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Strange, All I recall doing was adding the GM PID's to it.

Hook it up, turn on your truck, and open the app. Make sure she's reading live data, and then go to the screen where you can add displays. Pick the digital one, and start scrolling through the options. The one that works on mine is the Transmission Fluid Temp (GM Method 1). If it has live data available, it will light up green.

Be sure to throw in a digital readout for Torque Converter slip too ("TCC Slip Speed"). Really interesting. I never realized that all those times where it seemed like the truck "sorta downshifted" was actually the torque converter unlocking and slipping while accelerating. It almost turns a 4 speed into an infinitely variable transmission. Also makes an assload of heat though.
 

Kran

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thats exactly what i did when i had my monte carlo...worked just fine on that but not on here. ill have to try again!
 
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