19-20 Discussion on Missing Ambient Cooler

Well fucking said, Sir!

 

Umm, no. That’s not anywhere close to what I said or implied. Feel free to reread my post.

 

I’ve never seen so many people upset at how other grown adults spend their own money.

 

I read and understand your comment very clearly, as can be seen by my comment.

My Simpsons remark was frivolous in nature.

 

LOL!

 

Was that PC correct?

 

So I'm finally out from among the mountain men where there is cell data. The highest temps I saw was 223f on a very long steep hill letting the truck do its thing. Tow haul mode ON and truck in D. If I took over and ran it in 4S I only saw temps around 195f but my mpgs suffered. Best mpg was around 11 and worse average about 8.

 

Attached another csv log for a non towing trip showing transmission temp at pan averaging 216 (max it got 218) while it hit a Max of 236 on torque occasionally and that was while stopping and accelerating and goes back down afterward. outside temp was 86.

When I tow my 4000lb travel trailer , I'm Getting similar temps on s4 with tow/ haul on . This is all flat

Going camping next week , I will upload the collected data

 

Good info. I have been waiting to hear your report.

What conclusions are you drawing from the experience? Do you think the

$52 Hayden 679 Universal 11” Rapid-Cool Add-On Transmission Cooler to Enhance Cooling (not for direct replacement of the factory unit)

Hayden 679 has enough capacity for your towing? Do you plan to tow in D for the mileage, or in 4S for the lower fluid temp? Your Opinion: Do you think you'll still need to change the fluid more often at the temperatures you are seeing? Where was your highest engine oil temperature? Just mining your thoughts.

Maybe you'll give us a long, detailed write-up when you get back, and have some time.

 

Recieved my thermostat from @Roman yesterday. Put it in the future to-do box.

 

The Tundra software is pretty smart and putting it In D the truck could see 6th gear in downhill and level stretches of road. TC lock doesn't happen as much if you put the trans in 4S. Not concerned with 223f. Most of the time the transmission temps were 195f to 200f. If you really wanted the trans temps as low as possible you could run it on 4S and never see temps higher than 200f. The

$52 Hayden 679 Universal 11” Rapid-Cool Add-On Transmission Cooler to Enhance Cooling (not for direct replacement of the factory unit)

Hayden 679 works very well and it's and easy install if your fabricating your own mounting bracket also its has a lower price point.

I'll be changing the trans fluid more often than a regular service which according to Toyota is not required. Toyota considers WS a lifetime fluid and only change it under severe service. I could never get my head around that one.

 

Forgot to add, engine oil temps stayed normal and never exceeded 200f.

 

Huh. Well, that's good news. Please excuse my old-school Tundra ignorance, but does that mean they deleted the transmission auxiliary cooler and kept the engine oil cooler?

 

Nothing has changed as far as the oil cooler.

 

This is my stock 2018 calibration, thought the info might be useful. If the transmission fluid exceeds 257 F, or coolant temp 208 F, the torque converter switches to a hot lock up schedule. When comparing them generally the hot schedule locks later and holds longer. Not much help towing up a long grade where it never locks imo., but clearly operating over 257 F is planned for.

 

Fantastic information.

 

Here is another set of data from my last camping trip last week .
This is towing near 4000lb trailer with gears and family .
Factory settings , I tow with tow/haul on and S4 .
I uploaded 2 csv files from my round trip.
Temps always around 215 , occasionally goes to 235 on torque when I stop and accelerate and drops back quickly

 

And you do or don't have a cooler?

 

Factory settings , no additional cooler

 

My report after 2 weeks in the mountains towing 5.5k. Temps are a consistent 210f (pan) going up the longest high climbs. I left the trans in D with tow haul mode on. I just let trans do its thing. My mpg has been very good and ranges between 9 and 11. When climbing in doing the speed limited 100kph (60mph) and ambient temps are 30C. On the flats running 100kph temps are a steady 195f. We are in the BC's Okanogan country.

 

What were you getting for the same path without the cooler ?

 

I FINALLY got my OBD Fusion app working with the settings file from @jtwags. Last night I checked it out and was running 213-214 temps on flat interstate with the cruise set at 75. The oil temp was right at 200.

Edit: All stock, no extra cooler

 

Around where I live where it's slightly hilly and the ambient temps were around 20C (70f) I was seeing 245f at 100kph with the trans in D.

 

Was that on torque or pan ? Was that towing?

 

That was the pan temp towing the exact same load.

 

That surely was high , I towed last year in the hills up in Vermont and new hamshire my 4000lb trailer and never got the pan above 218 , but that was on s4 also running 55 and 60 mph

 

As a mechanical engineer I love these kinds of questions too. I geeked out on this exact issue for a few weeks a while back.

It's true that you should avoid roasting the trans fluid, but it's not the only thing in there that heat will destroy. From my research I found that the wire insulation and electrical connectors within the trans are the weakest link when it comes to multiple high temp heat cycles. Temps above 230°F will reduce the expected lifespan of those plastic electrical components even if the fluid, seals and other hard parts in the trans are not significantly impacted.

As I said in a previous post, $100-$200 for a good quality auxiliary cooler is much cheaper than replacing the transmission.

 

^ Exactly, and for those of us that keep vehicles 15 plus years those gremlins from cooked brittle electrical insulators can get expensive quick to diagnose and fix, especially if intermittent. Best to keep those temps down if possible.

 

OK well my recent temps driving in rolling hills ~8000' if that makes a difference in 75° ambient temperature were 205° to 235° I was mostly only going 55-60mph.

When I first got mine and was concerned and had a Scan Gauge I was seeing a minimum of 220°.

Since I tow a LOT (25' Airstream ~7000lbs) in desert southwest, upwards of 100° often,I have bought the ATF cooler kit here and think for my purposes a benefit.

I'll be towing once more before I install the cooler and will report those numbers in about a week.

G