Transmission service and best way to get transmission temp?

Hello all!
Well, I ALMOST sold my Tundra the other day! Nearly pulled the trigger on a $90,000 diesel one ton dually! My wife budgeted for up to a $1,200/month payment, plus my Tundra is paid off, and we'd be able to put money down, BUT, regardless, spending that much money on a truck is just a difficult pill to swallow!

Plus, I don't trust the CP4 fuel pumps on new diesels! When they go out its over $11,000 to have them replace and the system cleaned out! Wild!

SO, I'll be tasking my Tundra with some heavy duty work for a bit linger, even though she's got just over 100K miles now. Over the past year my wife and I have bought a heavy(ish) all steel car hauler, and a 27.5' bumper pull travel trailer. I figured that it was time to buy a one ton dually (I've always wanted one), but they're just so pricey!

My 2015 Tundra CrewMax has been a phenomenal truck! Every combination of what I pull is within the GRVW of the truck, albeit close to max, and probably work best left for a 3/4 or 1 ton pickup.

So, I removed the heavy 35" mud terrain tires and had the tire shop mount some smaller (285/75R17) Toyo Open Country R/T Trail tires yesterday. They're load range E, and rated for 3,968 lbs per tire.

Last week I ordered a pair of air bags and brackets for my truck. Each bag will lift 2,500 lbs. I get into some heavy tongue weights towing my '61 Cadillac Deville on my all steel car hauler, so the bags were needed.

So, we're getting ready to drag our travel trailer to the beach for spring break. I'm trying to get my truck all prepped for the haul.

New tires, air bags, air filter, and drained and filled the transmission pan with fresh fluid today. BUT, this drain and fill only replaced 4.5 of the 11 or so quarts of oil today! And, I measured exactly the amount of fluid that I drained and filled it with the same quantity. But, this half-arsed service is leaving me not feeling so good.

I've seen videos on how to pump all of the fluid out of the transmission. But, I don't have a way currently to get a reading on the transmission temperature, and I want to do right by my transmission! So, before I drop my rig off at the dealership, and HOPE that the tech does a good job, what's the best way to access the trans temp, so that I can make sure that my fluid level is correct, by slightly overfilling, and draining excess out of the overflow drain?

Also, if I'm going to pump all of the fluid out, I'm kinda considering adding an external trans cooler, with it's own fan. I have a brand new cooler, complete with fan, that has -6 JIC/AN fittings on both the inlet and outlet sides. Does anyone know exactly what fittings I'd need to connect my aftermarket cooler?

I know that this is a very long post! I appreciate anyone that has read this far, and would really appreciate any help on accessing my transmission temp and connecting my -6 JIC lines to the factory cooler lines.

PS - I'll add that I'm NOT trying to bypass my factory cooler. I'm wanting to add to it, to prevent my transmission temps from creeping up on long climbs. It won't over cool, as the fluid will still pass through the factory cooler built into the radiator.

Thanks,
Nik

The truck, with the new tires:


Trailer we're dragging:


Air bags:

 

I have the OBDlink MX+ it works right out of the box with the pan and torque converter temps, no need to add the codes manually like the cheaper OBD dongles.

 

I appreciate your response! I went and looked at them, and went ahead and made the order. Seems like a good investment at $140. I just downloaded the app, too, so should be ready to go when it arrives! Thanks for the reccomendation!

Nik

 

I use it all the time. This is how i set mine up.

 

Looks like I see a Barcelona 4R? How about some pics of the '61.

 

Yup. My wife's T4R.

Here's the '61 Deville:

It's bagged and swapped to Holley Sniper EFI. Otherwise stock.

Here's the latest money pit:

 

ATF drain & fill is totally legit. Just do it every 20-30k miles. In fact studies show it is better to d&f more often than to replace the whole fluid once in a while - ATF has to suspend less worn material and has more friction modifies.

> probably work best left for a 3/4 or 1 ton pickup.

Don't you get a rear diff size in 3/4-1 ton Fords and GMs similar to Tundras 1/2 ton? Gen 2 is built to tow.

 

Regarding the drain and fill, I agree. Though, I was less than pleased to see how black the fluid was. I was hopeful to see fluid that was more red; less black. So, I may do a full transmission flush, then just start doing the drain and fill every 10-15K miles. Or, I suppose that a drain and fill every oil change until it starts coming out clean may also be a good option.

And yes, my Tundra definitely tows well! It's got a very beefy rear axle and got a very respectable towing capacity. The only part that I don't like is the input from the trailer that you get into the truck, do to the trucks short wheelbase, and relatively light weight. But, it does tow well!

I REALLY wish that Toyota would get into the diesel 3/4 and one ton truck market. But, I'm also amazed that they haven't gotten into the sprinter van market! They would absolutely crush that market, particularly with a smaller diesel engine offering, like the Mercedes vans.

 

I think there is a way to check the temp thru a combination of shifting/button pressing that come on the dash. After doing that, once it gets to the proper temp, N will flash. You then have time to check the level.

I believe this is the video that mentions it.
https://www.youtube.com/watch?v=NUAuGmDGntY

 

Yeah, I know that you can short out pins 4 and 13, then turn the key on, and cycle back and forth between neutral and drive until you get lights to flash, then go to park (I BELIEVE this is the process) and the "D" for drive will tell you whether it's at an appropriate temp. I THINK that if the "D" light is off, the trans is too cold, if it's flashing, it's too warm, and if it's solid on, it's the correct temp. I was going to do it this way, but for $140, I'd prefer to just buy a tool that will give me a readout of the exact temp. It'd be my luck that I'd accidentally short the wrong two pins, and nuke my CPU, or something. Or forget to remove the wires shorting those two terminals, and cause damage, which I've read can happen! I'm gonna try to not let myself be too cheap on this one. I've got another Toyota that I'll also be able to use the reader on, so it'll be $140 well spent.

ETA: perhaps it's the "N" light that will tell you the trans temp, and not the "D". I don't remember.

I had watched this video:
https://m.youtube.com/watch?v=x97UZ...yYW5zbWlzc2lvbiB0ZW1wZXJhdHVyZSBjaGVjayBtb2Rl

 

How did you get it to display like that? Is that the factory head unit or aftermarket?

 

I believe that's his phone, with a small display from the OBDLink app, displaying over a navigation app. I don't think that's the Toyota head unit.

 

Ah, was hoping it was an overlay on a head unit (factory or aftermarket). I do like how that app is an overlay though.

 

That would be really sweet!

 

Its my tablet that I have mounted.