2022 Tundra Suplemental Transmission Cooler?

Awesome and thank you. So by pinning it it keeps the valve open? Should it keep the fluid temps to about 190? Would safety wire work?

 

• The pin will keep the valve open.
• Without being pinned the oil reaches 190°+ before leaving the transmission. The pin will allow the oil to flow as soon as you start the truck.
• I used 1/16" single strand wire. It was stiff enough to keep the plunger open. Boy for me without a lift it took some effort to push in the pin and insert the wire!

 

Any updates post pinning the stat? Had a look at the lines coming from the trans, appears ideal place mount lower temp bypass and run hose directly to external cooler.

 

Results of Towing:

A 3.5 hour per direction trip. Four mountain passes along the way. Camper weight loaded 2500 lbs. Using Tow-Haul mode. Thermostat pinned. Derale 13402 (32k btu) transmission cooler. Ambient air temp 90 degrees so the air was on the entire time while driving.

Cold start temps: Radiator 90, engine oil 85, transmission oil temp 85 degrees. Warmed temps one hour into travel, flat grade 60 mph: Radiator 190, engine oil 180, transmission oil 180. First mountain pass 1 and 1/4 hours into trip - 10,000 feet elevation: Radiator 195, engine oil 190, transmission oil 190. Second and third mountain passes (9350 ft and 9950 ft) 1 1/2 hours into trip: Radiator 190, engine oil 190, transmission oil 190. Next hour of driving with no mountain passes, flat to down hill grade: Radiator 190, engine oil 175, transmission oil 175. Fourth mountain pass, 3 hours into drive, 30 minutes from bottom to top, 12,100 feet in elevation, varying speed limits from 30 to 15 mph with many sub 10 mph hair-pin turns: Radiator 195, engine oil 200, transmission oil 200. Remainder of directional travel 30 minutes of down hill and flat grade, 15 - 30 mph: Radiator 195, engine oil 180, transmission oil 180.

The return travel saw similar results at each mountain pass location, and when towing on flat grade conditions. I would recommend a cooling unit with at least 50 % more cooling BTU. To error on the safe side "go big"(Derale 53481 59k btu).

BTW I averaged 16.5 mpg (tank) for this entire round trip.

 

With the T-stat pinned and going thru my 59,000btu cooler. I am staying under 180° without towing. I ordered the same T-stat you did (145°, wish they had the 135° in stock). I am planning on bypassing everything later this week. Run thru the 145° T-stat to the aftermarket cooler. My next towing adventure will be at the end of the month.

 

Sounds like you have found the ideal zone! 59K btu will be my next and final step. Which Derale model did you use?

 

I need that !

 

Those are good numbers albeit 2500# but still in warm conditions and at high altitude. 200° is no issue at all but lower is better. So where did you cut it inline? On the return line between the OEM puck and trans? *PS - incredible towing mpg!!!

 

I installed the Deral #53478, 34 row series 10,000 unit. It was a stand alone cooler with no mounting kit or fittings. As stated it has 59,000 btu capacity.

On a side note your 2500 pound camper must be a pop-up to get that great milage? Towing my 5200 pound camper I was getting 10.5 mpg compared to your 16+ mpg. My camper is 2x the weight as yours and I assume taller so a higher wind resistance than what you are towing. I am satisfied with my milage towing.

 

yes my camper is a pop-up. Went that direction mainly because it fits in my garage - 10ft box and 21ft when open. Forrest River 207SE. Easy to tow and as stated much less wind resistance. So many nice campers out there for us who enjoy the outdoors. Enjoy the summer, camper and truck! Thanks for the cooler information.

 

see post 178 - after the puck on the return feed to the transmission.

 

This is a "figure it out as you go" process. Below is a recap of what I have done and already posted in this thread.

• Installed a Banks Supergauge to monitor transmissions temperatures. First trip out with my 5200 pound camper the transmission temp peaked at 226 degrees!! This was not my first time towing, but first time with the gauge installed.
  
• Installed a Derale 10,000 series 59,000 BTU transmission cooler. Picked up the return line leaving the stock transmission cooler and sent the fluid through the Derale cooler. Towing the camper the temperature still peaked at just over 200 degrees. I feel this is still tool high a temperature.
• Discovered that the stock transmission thermostat opened at around 195 degrees.
• Pinned the stock thermostat open. Summer driving without the camper the truck stayed well under 180 degrees.

My concern here is I am still going through the stock cooler first, which is influenced by whatever the engine coolant temperature reaches. Towing for a long period of time I feel the transmission oil temperature will eventually match the engine coolant (as also stated by MaxPane3) in this post.
I live in New England so in the winter I would think I would need so type of T-stat just not one that opened at 195 degrees.

New Info

I finally bypassed the factory puck/warmer and installed the aftermarket T-stat.
I was going to install the Improved Racing FSC-145 T-stat in the location you pictured, but with the fittings it was too long. I did not want t cut the factory steel lines. The front rubber hose was too short.


I ended putting it up by the aftermarket transmission cooler behind the grill.


I have only driven the truck without the camper (will be taking the camper out tomorrow) and the temperatures are still under 180 degrees, but closer to that number. Here is what the specifications are for the Improved Racing T-stats. I did not read the fine print. The "full flow" temp is 163 degrees. This is still 30 degrees lower that the stock t-stat. I thought the "fill flow" was 145 degrees. I will see tomorrow what the temperature gets towing the camper. If it is higher than I want, because I used threaded connections, I can just remove the Improved Racing T-stat in the summer. Not ideal for I wanted a "fix it and forget it solution".



This was a concern, the color of the removed transmission oil. The truck only has 4400 miles on it and the oil is this discolored. I would expect some discoloration, but for the mileage I think this is excessive. Both containers are plastic and filled to about the same height.



I am leaning towards replacing the transmission fluid...???
I will post my temperature results after my trip this week.

 

Great info/write up. In addition to cracking at 145, I read all the T-stats flow 10% fluid to the external loop when closed. My intention for the T-stat is for the 5 month Northern VT winter and few -20f days.

FYI - the Improved unit went up $20 past couple weeks, Amazon still has them at old price $179.

 

Results of Towing test #2:

A 2.5 hour per direction trip. One major pass along the way. Camper weight loaded 2500 lbs. Using Tow mode (used Tow-Haul on prior session). Thermostat pinned. Derale 13402 (32k btu) transmission cooler. Ambient air temp 80 degrees, and the AC was on the entire time while driving.

Cold start temps: Radiator 90, engine oil 85, transmission oil temp 85 degrees. Entire out-bound trip is uphill. 1.5 hours into the trip to the only major mountain pass - 11,300 feet elevation: Radiator 190, engine oil 195, transmission oil 200. Remaining drive was one hour, and downhill to flat: Radiator 190, engine oil 180, transmission oil 175.

The return travel saw similar results at each mountain pass location, and when towing on flat grade conditions.

The Transmission Oil max temp reached was 200 - and like tow test #1 was only for a few minutes going up to the top of the pass(es) summit. I'd like to see the max temp stay in the low to sub 190's.

Low temps suitable to me not possible with the 13402 so I pull it and install the Derale 53481 (59k btu cooling). See results in later posts where I towed over mountain passes with elevations over 11,100 ft and 10,600 ft.

 

Thx for sharing your test 2 data. I’m ok with 200°, of course lower is better but 200° is within spec. If it was 100° ambient then it would have probably been too high. I’m really anxious to see your test results with the 59K btu unit. I’m going to wait before I buy. Thx again!!

 

do you have a device to monitor the temps other than what the oem readout dash unit provides? If not get one and you will find that your transmission oil temp is higher than desired even though the Mothership says it is "okay." As for hard shifting - do a search and see what you find. This is a Supplemental Transmission Cooler Thread Not a Hard Shifting Thread. BTW, based on the number of posts you have made in rapid succession it looks like you are trying to reach that magic number of 50 in record speed.

 

If I could ask a newbie dumb question, where exactly is the fill tube on these 10 speed transmissions? I know it's on the pan, and we have no dipstick...I just can't see it? Thanks.

 

Just trying to keep the thread on point - discussions and results of Supplemental Transmission Coolers. An impossible task but not too much to ask. So now to break with my request - likely your hard shifting transmission issue is not temperature related. Could be low on fluid or have a bad actuator(s) or both. Not sure what your truck's history is - bought new, used, tow, no tow, mileage.... Likely you will find more useful information on a thread that discusses your issue specifically. If it is under warranty take it to the dealer and see what they find. For sure get a Scangage II or equal product to learn what your truck is doing related to temps, charging,.... worth the $.

No dip stick. No fill tube. Fill plug on the side of the transmission. Only way to know if it is properly full or not is to do a "level" check.
There is a thread somewhere on the Gen3 posts for it. Similar to what is done for the Gen3 Tacoma (and likely the Gen4 Tacoma). The Pan has two bolts - one to drain the pan, and one to perform the level check with.

 

Apologies if I got us off point. Enjoyed reading this entire thread.

 

Tow test #3 results:

Two 135 mile highway towing legs - 55 mph to 70 mph. Two mountain passes each way -11,100 ft and 10,600 ft. Home elevation 5800 ft. Round trip tank fuel average 17 mpg using Tow+ mode.

Derale 53481 transmission cooler (59K btu/hr). Transmission thermostat pinned.

Max temps reached pulling uphill to pass summits: Radiator temp 193, engine oil temp 185, transmission oil temp 185, air temp 90 degrees.

Max temps on flat highway grade: Radiator temp 190, engine oil temp 170, transmission oil temp 174, air temp 90 degrees.

Overall I would say the transmission cooler setup currently installed performs as desired. I am totally comfortable with the towing results for all towing situations. I am certain non-towing results will be equal or better in every aspect.

I hope these reports and results help others make their decision as to what size unit to install. I'm satisfied with the Derale 53481 transmission cooler results and glad I up-sized. Happy towing. Be safe and enjoy your travels.

 

Excellent !! The 59K BTU shaved off another 15°. Those are perfect numbers IMO. Thanks again for sharing your test data. Those are the results I’m going after. *Note-Totally amazing towing mpg too.

 

Will report on last camping trip for the season in mid September. Basically a mild uphill and downhill trip of 380 miles each leg. Highway speeds 55 to 65 mph. A true test of a typical non-mountain towing experience.

 

when the general color of the oil is more brown than cherry red it is time to change. The darker the color the more indication of long periods of high heat exposure. Anything approaching 200 degrees for 30K miles is suspect. Take that number to 220 or over and you are pressing your luck with 30k changes. JMO.

 

@MaxPayne3 - is there a preferred fluid for this 10speed? Toyota WS , Aisin WS or Redline d6?

 

At some point I plan on using Amsoil SS blue cap aft. I’ve used in my 15 Tacoma that speced WS and did awesome on it.

 

If the ATF fluid expands at higher temperatures, what is the min or optimal atf temperature? I would think too cold of a temperature and your starving oil in the tranny to a certain degree?

 

150 PSI in oil cooler? Never. The valve body has a plunger that limits the amount of pressure reaching the cooler line. It has maybe a few PSI.

 

Hopefully those fittings are temporary, I don't recommend nor do I use hose clamps in my shop, transmission pressures can exceed 160 psi under load. I use AN fittings because they don't leak. There are AN fittings that don't require special crimping tools. It also uses a special type of hose for those fittings but once you push the hose onto the fitting it's permanent. If you've done home plumbing repair think of the Shark Bite fittings. If you need to convert between NPT and AN there are fittings for that too.
As for the fluid color, it's still got a nice red tint to it. The fluid is going to start turning darker naturally as it breaks down doing it's job. Not really much different than putting in nice honey colored oil in your engine and a week later it's turning black. When the trans fluid loses all the red tint and starts turning dark brown or black, that's a good sign it needs to be changed. Being in Arizona, I recommend to all my customers getting a service every 40k miles, or sooner if they are towing frequently. A transmission service every couple of years is cheaper than replacing a transmission.

 

@MaxPayne3 Can you provide PN or links to the fittings/hose recommended? is there a preferred fluid for this 10speed? Toyota WS , Aisin WS or Redline d6?

 

If 200 was max and not sustained while towing 2500 lb up to 10k ft then that is a great result. Interestingly enough, when I'm driving mine daily with no load in 110 degree plus heat, I'm already at 200-203 degrees trans temp about 10 miles into my commute and it stays pretty regulated between 193-198 degrees. Still too hot for my liking but I'm in a leased vehicle under warranty so I'm going to wait and see how things go before adding my cooler. This past spring I took a trip to the AZ Rim country, going from 1200 ft to almost 7000 ft on 6% grades with an unloaded truck and 4 passengers 80 degrees outside my trans temp got up to 228 degrees at one point. That's unacceptable for me.