Why did Toyota add the front diff temp sensor to the 3G Tacoma then delete it?

I have a 2017 TRD OR with the front diff temp sensor in the oil. It’s strange to me that I can monitor the front diff temp and not the rear diff, which arguably takes way more abuse.

Does anyone know what an overtemp condition on the front diff results in as far as the operation of the truck and its ECU? A warning message on the dash or limp mode?

Also why did Toyota get rid of this option on subsequent MYs?

 

What would the percentages of Tacoma drivers be that would need that?

 

Where did you read it was removed? From the 2023 owner's manual, page 488, under "Warning message and warning buzzer list": https://assets.sia.toyota.com/publications/en/om-s/OM04047U/pdf/OM04047U.pdf

 

Page 580 in the '19 owners manual.

 

this is what toyota has to say about front diff temps.



Sensor range

 

^Interesting. I've driven two hours in 4hi at ~60 mph (mix of dirt and gravel) without the temperature warning message coming on. Wonder what it takes.

 

Pure speculation, probably 250°F and higher

 

Same here. I've driven hours in 4 hi on pavement as well.

 

^Wonder if that's the reason the 4Runner Limited has a plastic duct on the front skid plate, to direct cooling air to the front diff. The 4Runner Limited is full-time 4WD, so the front diff turns all the time:

 

My understanding is after 2018/2019 the differential housing no longer has the bung for the sensor. When I got my truck regeared I was asked that question. If my info is wrong feel free to correct me.

 

https://www.tacomaworld.com/threads/front-diff-temp-sensor.697797/

Previous threat in this topic.

 

While the owner’s manual still has the note about front diff temp warnings, the front diff no longer has a temp sensor. I’m not sure exactly when they got rid of it but I believe it was either starting the 2020 MY.

I don’t know why they got rid of it, my best guess is they determined the front diff wasn’t something that actually needed any temp monitoring after all.

As to comparing front and rear and why one had the sensor and the other didn’t, it’s somewhat apples and oranges because you’ve got 2.5-3x the amount of diff fluid back there (keeping the heat spread out through more oil). You’ve also got a larger housing to dissipate heat to and in the OR/Pro/Manuals, you have larger/higher strength rear axle components to take the added brunt anyways.

 

I wonder how it determines if you need cooling time or to switch to 2WD?

I have driven hours and hours and miles and miles in 4WD and never seen either message so maybe it is irrelevant.

 

I've driven 8hrs+ in 4WD at highway speeds and never got a warning.... maybe because it was cold out? Snowy roads and all that

 

Normal driving in 4WD ain't gonna do it. Not sure what they were really thinking and it's pretty interesting to have but for sure completely irrelevant.

Only way I can think to over heat it is tow in front wheel drive only or sustain one front wheel spinning for an extended period of time. Who wants to try??

 

Maybe that's why Toyota deleted the sensor, same rationale they had with deleting the aux transmission cooler...