The Tacoma Towing Bible

Has anyone in this thread towed a Yamaha jet boat before? Specifically an AR190 or 195S. I am looking at getting one but it sounds like it would be a struggle for the Taco. I only live about 20 miles from the coast, so I won't be towing it super far.

 

I seem to be reading a lot of mixed reviews on towing in D vs 4. Out of precaution on the way home I kept the truck in 4 but boy did it kill my fuel mileage. My coworkers letting me borrow his quad for the rest of the year I’m towing on nearly flat highway posted 65-75. Can I keep it in drive? 06 sport package no secondary trans cooler.

 

I'd keep it in 4 when towing.

 

Yes, but not always. This is not a yes or no question.

It depends on the engine - how hard it's working over the terrain. Judge that by sound and feel. You should monitor transmission temperature - temp is also used as a guide toward gear selection. In other words, you have to "drive" the truck.

And 4 isn't always the answer, either. I've pulled down to 2 while towing - yes, it was a 3200 lb trailer, and a steep, long grade, so this is the exception, not the rule. But, I do use 3 quite a bit.

This is a very short version of a long answer.

 

@NEUMATIC ^^ this 100%. Buy yourself a scan gauge or something similar and program in the two ATF temp sensor outputs - you will see in real time how your driving and conditions impact temps in your transmission.

A converter is a fluid coupling device, rotors (fan like assemblies) running very close each other transfer the engine energy through fluid to the transmission. Heat is a by product of this transfer. When one rotor is mechanically turned by the engine the fluid moves and causes the other rotor (turbines) to spin. This is how an auto can stay in gear but not actually move at lower RPM. Now the lockup clutch is another part of the converter, Its a small clutch that works similar to a clutch in a manual but hydraulically applied and effectively bypasses this fluid coupling to eliminate loss under certain conditions, (When locked the auto transfers power like a manual trans.)

The reason you hear people recommending not towing in D 5th or 6th gears of an auto is because it allows the Taco to go into overdrive gear(s) which is a huge mechanical disadvantage and the converter can unlock in those gears which will generate massive heat. You have a heavy load on your Taco + stock gears + tall gears in overdrive (meant for cruising with little load) = massive heat generation if you are trying to keep up speed. The engine is transferring energy to an unlocked converter so the turbines are moving ATF to transfer energy to your trans. In tall, overdrive gears at freeway speeds with the load of a trailer the engine is at a mechanical disadvantage which makes it work harder and harder putting more and more energy into the converter which makes more and more heat. This massive amount of heat will fry your ATF and then your transmission will grenade because the ATF has lost its properties. That is why you should get a device to monitor your temps. Downhill = no big deal. I'll go into S5 on long descents or even S6 if I'm on the downslope of some massive mountain pass and have several miles to cruise

 

Do you know how to tell if your torque converter is locked up?

If you can keep it locked while cruising in 5th you should be fine to use it. It's when it starts unlocking that builds heat. It's not just the transmission shifting between gears that builds heat. So again, if you are driving on flat ground without a headwind, try shifting into 5th. It's easier to keep an eye on this when not using cruise control as well.

 

Did you mean not to use 5th or 6th when the transmission is unlocked, or are you trying to say 5th and 6th gears don't lock?

Also, he's in a 2nd gen, so no S5, S6, etc.

 

Got another question for you... when you say your mileage took a hit, what would you say your MPG is normally for this type of drive, and now with the trailer? These things really do start drinking it when towing.

 

I typically get around 17 on the highway and use just under a 1/4 tank getting to my hunting spot. I got home with less than half a tank. I only towed the quad on the way home. But just to maintain speed not going over 72mph I was running around 3k rpm. In drive doing 75 I’m normally at 1800 rpm. I am not climbing hills or going down any steep grades, 2400 feet of elevation to 3040 feet over 70 miles. Not sure exactly how to tell if the converter is locked or not. Any input? @YF_Ryan

 

I’m looking into the ScanGauge 2 but I don’t think it will show up before I leave on Thursday

 

In my experience when driving in 5th, the RPMs jump about 500 when the TC is unlocked. It's a smaller increase when it's unlocked in 4th which has been about 200-250 RPMs on my truck.

 

Drove the truck to work today and kinda felt what you’re talking about. Simple answer till the ScanGauge shows up is I’m gonna take the long way around my hunting unit. Speed limit is 55 4th gear should be fine till then. What are the average/normal trans temps you guys are seeing?

 

As @buzzkill911 mentioned, your RPMS will suddenly jump up a few hundred when it unlocks. Another way to tell is to slowly give it more gas and watch your RPMS, if you don't see a quick spike, but instead a slow raise in RPM and speed you are still locked, if it jumps up in RPM without much acceleration, you are unlocked. I'd suggest going out and experimenting a little bit and you'll catch on quick. I've never run a scangauge, but I'm sure it would be nice to have.

 

While the Scangauge is a cool tool, there are newer OBDII dongles that will sync to your phone. I read about them a lot on other forums. Not sure if they'll read transmission temps but it might be interesting to find out.

 

Scangauge can display both tx temps plus the current gear so you know easily if you’re unlocked or not.

 

How does temp and gear indicator tell you if you are locked or unlocked?

 

I notice it most, towing in 4th gear. If the tx doesn’t downshift but the rpm increases, it usually indicates an unlock. Also the TC temp will increase with an unlock. I can usually get it to unlock by tapping the gas pedal.

 

I'm just getting at trans temp and gear indicator don't clearly indicate whether you are locked up, as you stated?

 

The combination of current gear, trans temps on the scangauge, along with rpm, will allow me to know when the TC unlocks. Do you have the ‘current gear’ gauge displayed on your scangauge? We might be talking apples and oranges as mine is a 3G and yours appears to be a 2G.

 

I just don't understand how the scan gauge helps. Trans temps shouldn't be noticeably different when the thing unlocks. That'd take some time, whereas the rpm change instantaneously tells you it unlocked.