Transmission cooler missing…I know I know

Could you shift to 4Lo when doing slow off road driving?

 

Bahhh…Toyota

 

I had to shift into 4Lo in a few spots. It just kept my speed slower and rpm's higher, but I didn't get stuck LOL. I think it really was just a lack of airflow. My trans temp gauge stays dead in the middle 98% of the time, so when I saw it climb the other day it made my backside pucker...


This day I broke my front driver side CV and got stuck. I had to go back and CONQUER the area after I replaced the CV, and that day I noticed the trans temps getting up.



All fixed, but travelling with a buddy just in case. FYI, I like the external cooler system in the 2007-2018 Tundra's better than the 4Runner design at bottom of the radiator. As a previous 3rd Gen 4Runner owner I was already pre-disposed to be fearful of the "Strawberry Milkshake".

 

Bypassed the radiator and installed auxillary on my 18 4Runner at 25k. End of that nonsense. Also put a frame mounted hitch, airbags and e rated KO'2's on it too. Good to go now.

 

heat transfer performance won’t change to a meaningful degree.

going to full pao like amsoil makes it more resistant to heat degradation.

 

I should do that on my daughters 2011 4Runner......

 

One man did what Toyota couldn't, seems like little R&D cost to me???

 

No cost, except time when you dont have to answer to anyone elses pocketbook.

 

Yea that's it, definitely misread it.

 

https://www.tundras.com/threads/2011-2018-additional-transmission-cooler.80225/

Although this won’t help if there’s no airflow.

 

100* ambient - Approx. 3500-4000lbs total tow weight. Truck should have a cooler. Am I going to worry about it or add one? No.



That being said, I have had 2 times in the last month or so when I put the truck in reverse 1st thing in the morning and it just revs like it is in neutral for a couple seconds before it finally seems to "catch" and start backing up. I'll be bringing it in for my 10k mile service in the next couple weeks and will let the dealership know about it. My guess is they will not be able to replicate and I'll just keep driving it until it gets worse or doesn't.

 

That right there is exactly the proof that this system is flawed. No way in hell you aren’t degrading that transmission fluid at 260-270 deg pan to TC temps. And you aren’t even towing half what the truck is rated to tow. The one guy that posted that his transmission overheated and the warning lights and messages came on pulling a pass was also towing a 4,000 lb trailer, ridiculous.

 

Get ready for the fallout!! Soon they will be saying why 75 mph, how come this, why that? Many Toyota fanboys here can't accept that they were ripped off.

 

Don't get me wrong, I have read many of your posts and they are heavily biased towards justifying your decision to purchase the trans cooler kit for an issue that is yet to be proven. Fanboys on both sides here. My plan is to drive it until it dies or the lease is up and make a decision on what to do from there.

 

Those temps (260-270) are high and would definitely make me nervous. I haven't seen anything close to that high on mine, thankfully.

My trailer is about 4300 lbs and even in hills at 100 degrees ambient I run at about 220 with a max of 230, but I stay out of 6th and top out at 65 mph. I've seen people on here with the factory cooler (2018 and prior models) posting the same numbers as I am getting, so I'm not sure how effective the factory cooler is/was. The aftermarket ones seem to be highly effective.

 

Pretty spot on, if slow in 5th with a light load I was also about 230 ish. My issue is I want to see 600k out of the truck, so cooler it is.

 

No the fan boys will tell him he should be towing in S3 at 4000 rpms on the highway, and never exceed 45 mph towing and then it won’t get over 230 deg.

 

Exactly, and Toyota does not care if it only last you 60,001 miles, then it’s not their problem!

 

I see no harm in putting a cooler on, for sure. I still haven't decided if I will or not. I have a 100k mile warranty and plan to do more frequent transmission fluid changes, but overall I'm not too worried.

My travel trailer is listed as 65mph max, so that's what I stick with though I have definitely hit 70 more than once and without any significant temperature differences.

I am always curious too about the history over the years on the Tundras that were delivered without the towing package. I'm sure there are older Tundras out there without the cooler that have seen significant towing over the years. It would be good to hear about the history of those.

I am a mechanical engineer so it's rather interesting to read some of the comments on here about engineers and the decisions that are made.

 

I tow a 5500 camper pretty regularly with my 19 and have several thousand miles logged. I don’t know what my temps are running but i would assume pretty warm from the comments I’ve seen. I do tow in S4/5 and have never seen the transmission light come on. I know Toyota recommends towing 65 or under and i try and stick to that but some of these highways in Texas have 75mph speed limits and if I’m not towing at 70 i might get run over. 70 is about as high as i go though.

 

Biased?? Okay, but facts are facts. Even you are seeing excessive heat. You simply are not highly concerned, and are leasing, I however own, and I happen to care. So, somewhat of an apples to oranges comparison.

 

What’s hysterical is that trucks with tow packages all are designed with tow haul to be used in D but because we can’t keep the tranny temps down now it’s gospel to by pass it by using manual shift gears and staying in lower gears. Does anyone understand how stupid that is? I towed this 9000 lb boat 1000 miles in 90+ deg temps in D with tow haul on, at interstate speeds, and did it regularly with never an issue. Now I’m supposed to use the truck differently than it was designed to be used!

 

Thanks for this link. Very cool. I need to get under my hood quick and determine what I want to do. The link says price was $299 as of Sep 8, 2021. It's already increased to $349 in just 3 weeks. Yikes this darn "Inflation".

 

Fact - aftermarket cooler kit lowers trans fluid operating temp when towing.

STATEMENT UNSUPPORTED BY EVIDENCE - Transmission will be damaged by towing by increased transmission fluid operating temperature while towing.

Proof - None.

The only fact is that the cooler lowers the temp. There is no evidence that it is actually needed.

 

Two lanes are an option. Personally, I avoid interstates with travel trailer. Simply saw too many shredded over the years. Ounce of prevention is worth a pound of cure.

 

Except of course for 80 years of automotive science!

 

Is that below Keystone dam?

 

Well for some reason the mfg. designed a thermostatically controlled cooling system on the side of the housing. I guess it was to brighten the headlights or lower the drag coefficients. I dunno!