Towing with a 2016 and not going higher than 6th gear.

[bloc]

So you are saying that putting over 214,000 miles on the LC and somewhere over 100,000 on the LX without an issue isn’t enough evidence but you think that I need to monitor tranny temps? How many transmission failures are you aware of? I’ve seen one or maybe two on mud but that doesn’t seem like many. I understand that there are many different types of people on mud and I don’t consider my type to be superior, merely my type, and I don’t mean to discount the advantages of being a “numbers” person but I have quite a bit of actual hands on evidence that putting it in D and hauling yourself around doesn’t cause damage. You can do all the monitoring you want but I find that the surroundings are a lot more interesting. And, again, real life experience doesn’t indicate a need.
I just did a quick scan on my Gaia account and it shows over 20,000 miles of hauling the travel trailer from just over 49 degrees N to just over 68 degrees N but I don’t record the jet boat towing.

Good for you. It’s probably a good thing that you choose to do this in a vehicle that is so overbuilt, but a lack of failures for you does not mean you are doing things in a way that doesn’t abuse the transmission and fluid.

One advantage to towing in a lower gear is precisely that you can look at the scenery and not need to watch for the torque converter unlocking or worry about transmission temps.

You do what you want, but people on this board need to be aware of the risks of following your method.

 

[Fisher23]

Getting my 2016 LC200 ready to tow my 4k pound loaded travel trailer. Just installed a Redarc controller, and needed to purchase a 3 foot electrical extension for the trailer wiring hookup. The recommendation is to not tow any higher than 6th gear. I've read the manual and don't understand how to do this. Do I need to go into manual mode and shift every gear? I hope not. Haven't done all of that shifting since my 82 Hilux.

Sounds like your lc200 a diesel?

.. you will have no issues towing, but the recommendation is to put it in "S6" if you have that option.
Some guys down under run a torque converter locker, but I'm not familiar with it.

 

[GordJ]

You do what you want, but people on this board need to be aware of the risks of following your method.

Thats hilarious

 

[Dunbar]

When towing you so need to know the torque converter and transmission pan temperatures. You may have gotten away without knowing but if you get over a certain temp it's toast. Just like an exhaust gas temperature Guage on a diesel with a chip. My 7.3 powerstrokw can run 1175°F all day but at 1250°F it will melt pistons.
It's cheap insurance to get an OBD2 Bluetooth device and an App to monitor your systems.

 

[GordJ]

When towing you so need to know the torque converter and transmission pan temperatures.

I am continuing this discussion in the spirit of debate. I hope we can all learn something and not fall into the ”attack” trap

The only reason that the manual, in my interpretation, says to downshift on hills is because the engine isn’t, potentially, turning over fast enough to turn the water pump and alternator while coasting down a l-o-n-g downhill. Cooling and charging would be effected. And, duh, downshift to control speed on hills. The reason that lower gears in S is mentioned is because in the higher gears the gear ratio is such that the engine is actually being slowed down by the driveshaft.

In regards to your “need to know” line quoted above

No, you don’t. You want to. I understand that some of us want to know but it is far from important to know the temps. Again, 53 years of experience against theory. Show me the failures. For every one who saw his temp rise and acted accordingly ther are (insert number of magnitude here) more who drive oblivious to the issue and never know. You have a gauge because you want to and I understand that but for all the reported temp rises there are virtually no failures. Who’s right, the ones who see the rises in temps and call out for solutions or the ones who don’t see the rises and don’t see the failures? If there were failures your position would be credible but right now all you’re doing is preventing a problem that isn’t there. IMO!
There are vastly more 200’s driving around without gauges than with so there should be a plethora (just inserted that to lighten the mood) of burnt out tranny’s if high temps were a real world problem. There not even a dipstick! What does that tell you?

 

[Dunbar]

You don't need to know. I do.

 

[bloc]

There are vastly more 200’s driving around without gauges than with so there should be a plethora (just inserted that to lighten the mood) of burnt out tranny’s if high temps were a real world problem.

There are vastly more people avoiding overdrive while towing heavy because it has been taught as good practice for decades, and transmission temperatures are a primary reason for that.

Obviously I haven't done the actual poll but thinking about the people I know and work with, dozens of which frequently tow boats and travel trailers, if you were to ask whether those with automatics use the "tow-haul" mode if available or tow in a lower gear, the vast majority would do so. I'm pretty sure the broader public that actually tows would reflect this trend. For this reason your assertion that the lack of failures indicates it being harmless isn't a good argument, IMO.

Again, these things are overbuilt. If you had to choose a vehicle to drive with the TC unlocked, one with such a robust cooling system and two (maybe three?) transmission fluid coolers would be a great candidate. That doesn't mean it is the best way to treat the truck, and for those of us hoping to get 4-500k or whatever ridiculous number is fully within the potential of these vehicles, the smart play is use a lower gear to make it easier on the transmission, on top of boosting oil pressure and coolant flow.

As for coolant flow going downhill.. the engine would be producing virtually no power so there isn't really any heat to shed. Downshifting on hills has much more to do with controlling speeds than anything else, though yeah charging system when driving at night would be important too. By the way if coolant flow is a concern going downhill it should be much more of one when the engine is actually producing horsepower.. either flat ground with a large trailer (wind resistance) or going uphill with additional weight.

Along with "when using engine braking, do not put the transmission in 'D'" it also says "...shift range position must be in '5' in the 'S' mode" in my 2013 manual. I've been on plenty of hills where sticking to S5 would get me killed even without a trailer. I bring this up because the manual is clearly just a starting point to develop good practices when towing, and as you figure it out you adjust those methods to treat things right. Whatever the trailer, if someone wants to use a higher gear, learning how to look for the TC locking and staying locked in that gear would be a smart move. Or simply downshift and enjoy the scenery.

 

[GordJ]

Yes, I remember the Ford fiasco with their trannys and failure, everyone hit the OD off button right after startup (the cry "why can't they make this the default" still rings in my ears) but the trannys still failed, the Chevs before the Allison's and the Dodges before the whatever they have now. Not using OD or D was a stop gap measure that produced no noticeable results, those companies had just as many failures until they upgraded the engineering. In my uneducated option, shifting gears manually is just something that the manual gear shifters like to do.

 

[TeCKis300]

As much as I am a proponent of using sport mode, I tend to side with @GordJ on this one. The 200-series is a modern car. As with any modern car, it's thoroughly developed and validated. I wouldn't word things as strongly and would say using sport mode is an optimization. For heat and efficiency. But not a must. Same with watching temps. There's no need on a modern car that is fully developed and has faculty to manage and protect its components.

I've watched the OBD computer and lockup, and it'll lock just the same. Sure it may unlock more, but even the unlocking is a feature that multiplies power and torque without switching gears. Interestingly, you would think that downhill doesn't built heat in the tranny. But it does, as the torque converter is always unlocked during engine braking. The computer can monitor fluid temps and will likely exercise different duty cycle on the lock/unlock to keep heat in check. Managing brake pad heat is a different animal as the computer has no ability to assess temperatures there. And this is the situation that is called out in the manual for the driver to manage. Trading heat in the caliper braking system for added heat in the transmission.

 

[Fisher23]

What exactly is the safe temperature for the transmission when driving?

I know on my other vehicle if it's not in 4 low in the soft sand the temp goes up really fast.

 

[bloc]

There's no need on a modern car that is fully developed and has faculty to manage and protect its components.

The majority of which apparently have “lifetime” transmission fluid..

I didn’t know our torque converters unlock under engine braking though. That’s interesting.

 

[TeCKis300]

What exactly is the safe temperature for the transmission when driving?

I know on my other vehicle if it's not in 4 low in the soft sand the temp goes up really fast.

Safe is probably a loaded question. There's a lot of headroom in modern fluids, with probably the ability to go well into 260*F+. It's a sliding scale though, with the trade of high temp use with shorter change intervals. It's maybe @bloc 's point, that if we're using it to high temps over longer durations, is not going to be a lifetime fluid. Managing fluid temp would be akin to managing fluid life and perhaps why it's not a bad practice to use S mode.

Here's a relevant article where the latest Tundras remove the tranny cooler. They use the 6-speed that is common to pre-2016 200-series. Engineer sees no problems with fluids almost into 250F range.

Video: Does The 2021 Toyota Tundra NEED A Transmission Cooler? We Find Out On The Ike Gauntlet!

In this Ike Gauntlet test, we push the 2021 Toyota Tundra transmission to its limits to see if it in fact needs a transmission cooler.

tfltruck.com

 

[bloc]

@Fisher23 that is a great example. Most transmissions can’t lock the TC at all in the lower gears you’d be using in soft sand, so your ATF temps will quickly rise. Using low range more than doubles the torque to the wheels for a given engine RPM and gear taking a lot of load off the converter.

Safe is probably a loaded question. There's a lot of headroom in modern fluids, with probably the ability to go well into 260*F+. It's a sliding scale though, with the trade of high temp use with shorter change intervals. It's maybe @bloc 's point, that if we're using it to high temps over longer durations, is not going to be a lifetime fluid. Managing fluid temp would be akin to managing fluid life and perhaps why it's not a bad practice to use S mode.

Here's a relevant article where the latest Tundras remove the tranny cooler. They use the 6-speed that is common to pre-2016 200-series. Engineer sees no problems with fluids almost into 250F range.

Video: Does The 2021 Toyota Tundra NEED A Transmission Cooler? We Find Out On The Ike Gauntlet!

In this Ike Gauntlet test, we push the 2021 Toyota Tundra transmission to its limits to see if it in fact needs a transmission cooler.

tfltruck.com

Plenty of “lifetime fluid” cars without towing or any real severe duty have trashed ATF when it is finally drained at 150k or whatever number you like. That burnt/abused/just worn out fluid has reduced ability to protect the pump and clutches.

Also my understanding was the 260F ATFs were generally synthetic, of which our WS fluid is not. Not that I want to get into that debate again. It’s possible WS has a special sauce that helps keep it stable at elevated temps but conventional wisdom had me setting 240 as an upper threshold for conventional fluids, so not too far off the engineer’s number. But we don’t need to let ours get that high if we use the appropriate strategy.

Point is.. yes. Treat the stuff right, it’ll treat your transmission right.