Auto. Transmission Temperature Parameters When Towing

Thank you for the info. I'm going to pin the thermostat open and see what our temps are pulling the trailer before going with an aftermarket cooler. All the towing we'll ever do will be in flatlands. No long or steep grades.

Is there a video tutorial I can study up with in reference to pinning the thermostat?

 

The Tacoma is a well engineered vehicle for sure. However, and this is for all vehicles, they all have a certified limit but the design is always for the "middle" not the upper limit. For example, your truck's RPM limit is 6500 or so rpm. Sure, it will do it but it's hard on the engine if you do it all the time. Same as towing weight. My Tundra will tow 10K but I will never put more than 7K back there just because the manufacturers say I can. I typically halve the specs, because that is what will give me lest life and performance.
I put 6500 behind my Tacoma once. It was not pretty and I have been towing all my life.

 

check out this thread. Op has a good picture of it. It’s on the passenger side climb under and look for this. I bought a cheap spring c clip. U push the plunger in I used a screw driver and while holding it in you insert the clip through the small holes to keep the plunger pushed in.

https://www.tacomaworld.com/threads/someone-talk-to-me-about-pinning-the-transmission-t-stat.682424/

 

I'm with you 100% regarding staying back from the certification limits. What you're stating is sound logic, for sure.

The most weight we'll ever be pulling with the Tacoma in 5,000 lbs. 2 1/2 ton is 1,800 lbs. less than maximum towing certification. That is more than 25% less than the maximum towing certification of our Tacoma. Granted, that is on the high side of "middle" and 25% above "middle" but I don't believe it is unrealistic to expect the truck to handle those weights. Again, maybe I'm expecting more than I should be.

 

If you’re staying in the flats. Keeping it below 65, and you are absolutely required to be using a proper WDH for a trailer that size and maybe even airbags you’ll be fine. Get yourself a really good brake controller too, i recommend the Prodigy P3. That’s my setup for towing with airbags. Keep er slow. It’s gonna really struggle going up grades at that weight and no regear but it will do it slowly.

aftermarket Trans cooler could be a good idea, but I don't see how it will make much difference if the T stat isn't pinned open also. temps will stay in the 190-195 range even with the added cooler because of the T stat. I guess it will just help to cool it once it actually opens going up a grade. I'd rather start out at 165 before going up a grade and give myself a bigger cushion.

 

Thank you sir. As you can see I'm new to the Toyota Tacoma experience and new to this message board and you have saved me a lot of time pointing me in the right direction.

 

I don't really have to try hard to hit these numbers in the summer. I've since upgraded my trans cooler so it'll be interesting to see what affect it has.

 

The Ranger we pulled with prior to purchasing the Tacoma had the 4.0 liter V-6 that developed 207 HP and 238 ft. lbs. torque. The old Ranger handled the tow load very well on the terrain which we towed. As I'm sure all of you are well aware the Tacoma is rated at 278 HP with 265 ft. lbs. torque. That is a full 25% more horsepower and over 10% more torque. Just gotta' believe the Tacoma will do quite well pulling the same load on the same terrain.

Although I haven't had the opportunity to get numbers regarding hitch weight the trailer we're pulling causes the Tacoma to squat very little. So little as to make me skeptical that the truck needs any additional weight carrying help.

 

link to this upgrade? I need

 

Naw, that's fine especially in Illinois.
My point was... any time you have an expectation from a vehicle... be it speed, handling, performance, towing or anything, always strive for the middle in order to get longest life because when you start modifying in order to improve one of the above, you make the vehicle suffer somewhere else.

The truck will do 105 mph but the engine longevity will decrease. Same with towing only now the transmission suffers. Even though you are keeping it cool the additional loads are still there and that will reduce the life of the clutch plates, even though you are keeping it cooler.

By keeping my limits "in the middle" I compromise but don't have to worry about the decreased longevity.

 

https://www.mishimoto.com/heavy-duty-transmission-cooler-kit-electric-fan.html

Keep in mind that's just a universal kit so you'll have to figure out mounting and running the wiring.

 

was your wiring difficult?

 

The 4.0 ranger delivers its torque way earlier in the rpm range. Not saying its a better tow vehicle but comparing peak output numbers between the two is pointless.

 

I towed the same trailer in the picture i posted above with the 4.0l 2007 4runner, and with the 3.5l tacoma. I do agree that even the Toyota 4.0L engine spun less rpms and seemed to pull with more power to me. the Taco does have more power, but you gotta get up to 3.5k+ rpm to feel it. Gears really help these 3rd gens, Truck pulls like a champ now with 5.29's

 

I just cut the connectors off the mishimoto fan, installed a Deutsche connector and ran wires to my switchpro. It's not fancy temp operated or anything, but we'll see how it does.

 

so with your switch pro you choose when it turns on, or is it automatic? Can this not be wired into the default wiring of the OR transmission cooler?

 

Pull the same 4800lb Hideout with the 2005 and the 2017;

4.0 might have gotten it going at first but as far as pulling on hills and going down the highway the 3.5 does it better, cooler, and gets better mpg.


(old pic,3rd Gen now has 265/70R17 E RTs)

 

I understand where you're coming from and I also understand that the Tacoma is not, and never has been, intended for heavy towing service. That said I purchased the truck with the expectations of it being capable of towing at least a reasonable percentage of it's certification.

I've pulled the trailer in question with the Tacoma a couple of times for short distances and it has a noticeable power advantage over our old Ranger. As you stated, it's also obvious that the sweet spot develops at a higher RPM Tacoma but once it gets there the difference is significant. All that said I really don't believe one is any more suited for towing to it's maximum than the other.

 

Agreed. That is our conclusion having now towed with both.

You're pulling just about the same weight (but with significantly more wind resistance) as we will be towing. What has been your experience in regards to transmission temps concern's?

 

I choose when it turns on. It is not automatic. The stock OR only has a cooler, no OEM fan.