Tranny Cooler Upgrade Planning

[skrypj]

Good question and I'm not sure. If it's like the 100-series, the electric fan is primarily for the AC condenser.

I put my tranny aux aux cooler inline with the main mechanical fan for the active airflow. To help slow crawling and sand work.

Yeah and thats how my GX was setup too and it seemed to be fine at lower speeds. Even if the mechanical fan clutch is not engaged, its still turning.

The Jeeps fan was mainly for AC to but but could trigger based on transmission temps.

 

[Valgrind]

Correct, they don’t lose efficiency from normal use. Any routine reduction of the stock coolers would just be from buildup on the fins which can be addressed by careful cleaning.

Never thought about this, but should radiator cleaning, similar to an AC be done as part of a maintenance schedule?

Also, what is the safe temp range for the transmission? I had a 5k mile road trip and I was getting nervous anytime it was over 200F, so id slow down.

 

[linuxgod]

Also, what is the safe temp range for the transmission? I had a 5k mile road trip and I was getting nervous anytime it was over 200F, so id slow down.

What's your definition of safe, and which temps are your monitoring?

If your torque converter temp gets above 266F the transmission will drop down into 3rd gear to try to help cool it, and will lock out gears 4-6 until the temp gets back down to 230F. The A/T temp warning light doesn't come on until ~302F though and turns off around 275F. So my interpretation is that Toyota thinks it's safe so long as the torque converter temp stays under 266F, but someone might argue 230F should be the target.

In OBD Fusion right now I have anything below 230F in the green zone, 230F-266F is yellow, and above 266F is red. Note that the FSM doesn't specify behavior for the pan temp, which often runs cooler than the torque converter and will lag those temperature changes.

 

[Valgrind]

What's your definition of safe, and which temps are your monitoring?

If your torque converter temp gets above 266F the transmission will drop down into 3rd gear to try to help cool it, and will lock out gears 4-6 until the temp gets back down to 230F. The A/T temp warning light doesn't come on until ~302F though and turns off around 275F. So my interpretation is that Toyota thinks it's safe so long as the torque converter temp stays under 266F, but someone might argue 230F should be the target.

In OBD Fusion right now I have anything below 230F in the green zone, 230F-266F is yellow, and above 266F is red. Note that the FSM doesn't specify behavior for the pan temp, which often runs cooler than the torque converter and will lag those temperature changes.

View attachment 3662173

Well, I was going to ask how to get the different temperatures of the torque converter and such. My definition of safe is that I have unknown milage on the ATF fluid, and at this point everyone says it's better not to change it, so trying not to cook that anymore.

I just have a scanguage 2, so wherever it pulls the transmission temp from. I will try OBD fusion, I should have a compatible Bluetooth adapter.

 

[linuxgod]

Well, I was going to ask how to get the different temperatures of the torque converter and such. My definition of safe is that I have unknown milage on the ATF fluid, and at this point everyone says it's better not to change it, so trying not to cook that anymore.

I just have a scanguage 2, so wherever it pulls the transmission temp from. I will try OBD fusion, I should have a compatible Bluetooth adapter.

Scangauge should work, I just don't know how to get the PIDs you need. There should be 2 PIDs for transmission - one is pan and the other is torque converter

OBD Fusion is $5 and then it's an extra $10 for the Toyota Enhanced PID pack, plus another $20 or so for any ELM327-compatible OBD2 reader (if you don't have one). The upsides of OBD Fusion are (a) they include all the PIDs and (b) several of us have dashboards you can import.

 

[Valgrind]

Scangauge should work, I just don't know how to get the PIDs you need. There should be 2 PIDs for transmission - one is pan and the other is torque converter

OBD Fusion is $5 and then it's an extra $10 for the Toyota Enhanced PID pack, plus another $20 or so for any ELM327-compatible OBD2 reader (if you don't have one). The upsides of OBD Fusion are (a) they include all the PIDs and (b) several of us have dashboards you can import.

I'll check again, I couldn't get more than one PID to work last time.

I also never got engine oil temp or pressure to work. Not sure if there even is an EOT sensor. Does OBD fusion do any of that?

 

[linuxgod]

I'll check again, I couldn't get more than one PID to work last time.

I also never got engine oil temp or pressure to work. Not sure if there even is an EOT sensor. Does OBD fusion do any of that?

Engine oil temp works. I've not found a PID for oil pressure.

The green ring lights up when the torque converter locks up, and turns off when it unlocks. I find that helpful. If it's locked both pan and TC temps will stabilize at the same value, but if it's unlocked the TC will run hotter than the pan. Screenshot of the dash below, the dropbox link to import it is in this post.

Of note: before I re-geared my pan and TC would sit around 196-200F most of the time and engine oil was similar. Since re-gearing my pan and TC and engine oil tend to sit around 214-217F. This is true whether I'm towing or not. I assume that's a function of more resistance in the drivetrain and everything constantly spinning faster as I've seen others post similar results. Anyway I change my transmission fluid every 30k miles... probably overkill but since I'm always running 15-20F hotter than normal I figure $200 a few extra times is still much cheaper than a new transmission

 

[skrypj]

Engine oil temp works. I've not found a PID for oil pressure.

The green ring lights up when the torque converter locks up, and turns off when it unlocks. I find that helpful. If it's locked both pan and TC temps will stabilize at the same value, but if it's unlocked the TC will run hotter than the pan. Screenshot of the dash below, the dropbox link to import it is in this post.

Of note: before I re-geared my pan and TC would sit around 196-200F most of the time and engine oil was similar. Since re-gearing my pan and TC and engine oil tend to sit around 214-217F. This is true whether I'm towing or not. I assume that's a function of more resistance in the drivetrain and everything constantly spinning faster as I've seen others post similar results. Anyway I change my transmission fluid every 30k miles... probably overkill but since I'm always running 15-20F hotter than normal I figure $200 a few extra times is still much cheaper than a new transmission


View attachment 3662278

Which ring lights up on lockup? the AT pan temp?

 

[Valgrind]

Engine oil temp works. I've not found a PID for oil pressure.

The green ring lights up when the torque converter locks up, and turns off when it unlocks. I find that helpful. If it's locked both pan and TC temps will stabilize at the same value, but if it's unlocked the TC will run hotter than the pan. Screenshot of the dash below, the dropbox link to import it is in this post.

Of note: before I re-geared my pan and TC would sit around 196-200F most of the time and engine oil was similar. Since re-gearing my pan and TC and engine oil tend to sit around 214-217F. This is true whether I'm towing or not. I assume that's a function of more resistance in the drivetrain and everything constantly spinning faster as I've seen others post similar results. Anyway I change my transmission fluid every 30k miles... probably overkill but since I'm always running 15-20F hotter than normal I figure $200 a few extra times is still much cheaper than a new transmission

This is super helpful. Thank you!

 

[linuxgod]

Which ring lights up on lockup? the AT pan temp?

The green ring around the gear (number "5" in my dashboard screenshot).

It's really a second gauge which is slightly larger than the gear gauge. The gear gauge sits on top of it so they're stacked... if you removed the gear IIRC the entire circle behind it is actually filled green. You could do this with any gauge you want

 

[skrypj]

The green ring around the gear (number "5" in my dashboard screenshot).

It's really a second gauge which is slightly larger than the gear gauge. The gear gauge sits on top of it so they're stacked... if you removed the gear IIRC the entire circle behind it is actually filled green. You could do this with any gauge you want

Thats cool! I have not really spent the time messing with it, basically just shoved the key PID’s in and went

 

[lx4dp]

Scangauge should work, I just don't know how to get the PIDs you need. There should be 2 PIDs for transmission - one is pan and the other is torque converter

OBD Fusion is $5 and then it's an extra $10 for the Toyota Enhanced PID pack, plus another $20 or so for any ELM327-compatible OBD2 reader (if you don't have one). The upsides of OBD Fusion are (a) they include all the PIDs and (b) several of us have dashboards you can import.

Interesting. ObdII.