Transmission temps when towing

I recently purchased a '17 tundra trd pro. It is the first truck with an automatic transmission that I have owned and I will be using it for occasional towing of my travel trailer with the trailer having a max weight rating of 6500lbs. I notice that my tundra lacks a transmission temperature gauge and it doesn't seem to even have an idiot light for overheating. I will use the tow haul button for towing to reduce transmission temps but are there any other recommendations on how to tow with an automatic transmission to reduce heat. Also, are there any good options for monitoring transmission temps?

 

I use a Scan Gauge II to monitor my trans temps. It plugs into the OBDII port and you can configure it to monitor lots of stuff going on.

I do believe there is an idiot light for trans temps, but I certainly wouldn't want to rely on that cause once it comes on it's too late. I tow a smaller travel trailer (around 3500 pounds) and I monitor my trans temps pretty closely. I live in Phoenix AZ and tow up into the mountains all the time. I would say average temps hover around 200 degrees, and on long climbs uphill approx 6% grades temps climb to 225 to 230 degrees. These are on hot days of 100+ degrees.

 

X2 for the ScangaugeII. I have mine mounted (with Velcro) in front of my gauge cluster on the steering column. I tow a 4,000 lb camper and my temps are almost always in the low to mid-190s in S4 in tow/haul mode. In this pic I was near the top of a mountain so the temps had increased slightly. I like the ScangaugeII because you can program it to monitor the temps at the pan (TF1) and the converter (TF2). I know several folks have downloaded an app that provides the same features.

 

Since I have that bullydog hooked up recently, my trans temp stays about 190-200 not towing anything ¯\_(ツ)_/¯ don't know how accurate that is but when I'm driving a lot of highway and but it's like 115° outside it's been up to 205°

 

The bully dog has a nice looking display on the web site. Would you recommend that for gauge monitoring and tuning or is it overpriced and over hyped?

 

I wonder why they did away with the gauge on the third generations. The second gens have them. Seems an odd thing to remove...

 

I tow 6500lb tt and I do drive and tow mode Fl is flat but hot as hell, I don't have a temp gauge yet but I crawl under and feel for excessive heat as soon as I pull over and it all was feel normal.. Will be looking for a temp gauge soon..

 

I think the gauges are really cool and you can check everything on them.. it will display like 4 at a time from trans and engine temp, battery volt, miles per gallon, rpm and on and on.. I have t messed with the tuner since the guy who installed it did mine.. besides that it's cool and it's like $350 right now ¯\_(ツ)_/¯

 

I would be afraid the engine/drivetrain warranty would be void with the Bully Dog. Anytime you mess with the tuning the warranty is done.

 

You just put it back to stock tune and that's it, take it in ¯\_(ツ)_/¯

 

If you pin the temp regulator open will it affect mileage via computer compensations?

 

On my 2010 - with Trans cooler, and Bully dog to monitor the temps...

relatively chilly (under between 40 and 60 or so degrees - as the BD is relatively new to me..but towed with tundra in the past) days...I have found the following

Driving normally, highway speeds, in D about 65 MPH...My Engine Trans Temps would get in to the low 190-195 Range after a few hours of driving...would vascilate up and down a bit...but between 180 and less than 200...for the most part.

Towing my 6500-7000 pound camper...for the same run (had to drop off the trailer for some work, and pick up...so the terrain was relatively exactly the same, hills, etc.)

I use S4 and Tow haul...and keep the RPM right around 3000 (+-) which is about 65 or so on the highway in this gear.

My Engine Trans Temp were a tick higher...not much...but never went above 200 degrees...bounced around 190-199 for the trip...keeping both relatively cool for the run.


On a separate drive from Pa (near Philly) to the DE beaches (not too many hills to speak of...but some elevation changes, bridges, etc..) I towed S4 the whole way down - still under 200 (looked like it wanted to go to 200..but came sown immediately to 199 or 198 or so...while trip...

On the way back, on a section of Rt 1 near Dover...pretty flat...I placed in S5 to see what happens to the temps...it immediately shot up to 205...not a huge change..but a difference to be certain...I placed in S4 and after a few miles it came down to 199


for me, I will take the loss in MPG to keep the engine and trans in as cool a state as possible...shifting gears causes heat...and when at speed, needing 4-5-4-5-4-5 (whatever) causes more heat than just leaving in 4 and letting the HP / TQ do its job...plenty of power on demand, and just doesnt care ...


while not a perfect testing platform to be sure, the information that it returned seemed to show - keeping it in the lower gear causes less heat build up, and provides gobs of available on demand power - good enough for me.

the on-board temp gauge - never moves, and is not really calibrated to show a difference between 195 or 199...but the digital gauge does.


now....that is for the highway....I also do some towing in the local areas where the speed is not 65...but 45-50 or so...in that case. If I am just tooling along getting on the highway...I'll leave in S4...If im going to be driving a few miles and there are some hills...and the speed is 45-50 (like most of Virginia it seems and parts of NY, PA..etc) I will leave in S3 and prevent it form wanting to get in to 4th to save gas...my RPM are around 3000 (sometimes higher if I need more grunt)...but never a problem. just tows like a beast. Occasionally, I will need more RPM to climb some steep hills (10% grade for 3 miles around Lake Raystown comes to mind...) Ill grab 2nd and let the beast EAT for the trip....coming down...will also use 2nd, and get the RPM up to help hold back the trailer...and use the trailer brakes to initiate a slow down before engaging the truck brakes...someimes just tapping the truck brakes does not send enough signal to really stop the trailer...engage the trailer brakes...then roll on the truck/trailer brakes...works well


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