What do I need to do to keep my "new" 2021 Tundra happy?

I brought home a clean 2021 1794 Edition that spent its life in Texas. 45k miles.

I've already got Bilstein 5100 shocks, 17x8.5 rims, and 285/70R17 tires ready to install next week.

Curious about what maintenance or mods are crucial for keeping this truck happy and reliable.

I am planning on tons of mods to make it more capable in the woods, but want to address any known weaknesses.

 

Transmission cooler would be 1st on my list.

 

Just do exactly what the maintenance manual says. If it didn't come with one, get one at the dealer. It covers everything needed.

Dan

 

If your goal is longevity, then I would recommend an aftermarket cooler with the OEM parts from pre-2019 Tundras (OEM thermostat, OEM rubber and hard lines) so that your tow-package-equipped transmission will operate as originally designed.

Monitor temps (whether you install a cooler or not) with an OBD port reader. I use the Veepeak bluetooth reader, and it pairs to my phone, where I have the Fusion app set up with trans pan, trans TC, engine oil, engine coolant, lockup status, and battery voltage monitoring.

There are also two maintenance schedules: nearly everyone fits into the accelerated schedule. Toyota tells us to stick to 5k oil changes if we drive on dusty roads. I beat on my '21 a lot harder than that, so I am sticking to the accelerated schedule. It should be in your glove box. If not, it's online.

A simple 2" lift up front will allow you to fit skinny 35s (285/75s). That is your maximum sidewall with no trimming, cutting, or cab mount chop needed.
If you plan on hauling or towing heavy, you'll want some help for your stock rear leafs, which were engineered for maximum articulation and not so much for weight in the bed.

I would also suggest an actual front skid plate and, depending on your location, a cat theft deterrent plate.

 

As far as keeping the truck reliable - frequent oil changes and fresh filters are the easiest and most cost effective way.

The drivetrain is proven solid - some will say higher octane fuels - I’m not among them - quality 87 is fine.

Transmission cooler proponents - why ? I would absolutely agree in adding this if there is any indication of rosing or long periods of use in traffic/ hard miles or other indicators of stressful use on the transmission - but for standard usage - the transmission fluid shouldn’t be getting that heated. Just get a tool to monitor things and change fluids regularly.

 

This is very good advice, obviously from an owner with great experience.

When I commuted 320 miles RT per week, I stayed with the 10k oil/filter change interval. Once I retired (first of 2022) I switched to the 5k interval since I mostly drive to town and back (short range).

Dan

 

This. Pretty sure the 4.6s didn’t have anything but the puck and they have been fine. If you aren’t towing you probably don’t need the auxiliary cooler

 

The tow package equipped trucks all had the cooler. Was there a single 5.7L truck without the cooler before 2019? I’m not sure there was.

Even if he has no plans to tow anything, OP mentioned making his truck more capable in the woods and wanting the truck to last as long as possible. Given those goals, I think it’s a worthy mod. Off-roading, especially in 4Hi, causes sustained elevated temps.

Also, it sounds like OP lives in the mountains. I remember my pan temps just cruising the speed limit on the highway in the hills of middle Tennessee reaching ~230°F. That’s part of the reason I went ahead with the cooler install myself.

There’s a Tundra transmission cooler install video on YouTube that makes it SUPER easy.

 

The massive failure rate of 2019 and up Tundra's that do not have a transmission cooler is crazy. I mean everyday on this forum there is another Tundra transmission failing due to the absence of the cooler. NO, THERE IS NOT. AT ALL. NONE. ZIPPO. Everyone is just assuming something that has not happened. Yes, my cousins friends dad's ex-wife's dog said it so it's true.

More importantly is knowing what maintenance has been done in its 45K of ownership. If the records showing nothing then front and rear differentials along with transfer case fluids need to be changed. You really should also consider getting on a regular and basic transmission drain and fill service which there is a ton of info on this forum discussing it. Nice truck and good to see you're obviously wanting to take care of it.

 

Each person should make their own decision, but the OP asked about the weaknesses. No cooler+towing is going to reduce the ATF fluid life. That’s why transmission coolers exist.

Not sure I’d call it a “crucial” upgrade, but certainly an upgrade to provide some more longevity and peace of mine, especially if you tow.

 

Cooler debate! It’s about to get rowdy!

 

Good grief, don't listen to anyone but me.


Your truck won't be happy until you put in a Supercharger.

 

Did anyone mention gas? They love gasoline. Feed it lots of gasoline.

 

Tranny cooler, aftermarket rear leaf springs, TRD pro headlights, greasable u joints, seat covers, dash mat., differential oils, transfer case oil 75w Toyota oil., Transmission drain and fill twice 200 miles apart, wiper blades, air filter, cabin filter, rodent proof the HVAC fresh air intake under the cowling at bottom of windshield, you don't want mice in the HVAC system. Start saving for brake rotors, put in a battery, factory batteries are junk. Then there are about a thousand other things, and once you spend about 50 grand you will have a pretty decent ride. Good luck with your upgrades and your new side hustles!!

 

Air Injection Pump bypass. There are kits available. Once this thing malfunction, i.e. stuck open, the truck will be in limp mode.

 

OP your truck looks great. what kind of a bed cap is that?

We've got a member here with I believe a 2014 5.7 with 600k miles you should reach out to/follow re: maintenance. Name is "doggunner"

 

No one who is pro-cooler thinks there are tons of failures right now. We’re not even out of the 5yr factory drivetrain warranty yet. And actually, there have been a couple reported on the forum. One guy had a service ticket written up for his 2020 that he towed 3k lb daily with—it said that the transmission fluid was black and burnt smelling, and it noted that the external cooler had been removed. He got a new transmission from Toyota and never logged back in on the forum.

The key here is LONG TERM. Most if not all of us decided on the Tundra due to the insane durability and longevity of the now 15-year-old early 2nd gens that went and/or are still going extremely high miles. This transmission in the 2019-2021 trucks is the exact same as in those trucks, except it’s missing the external cooler Toyota originally designed it to come with as part of the tow package.

I think I speak for most of us pro-cooler folks when we say we just want it to operate as originally designed for the long term should we choose to keep it well past the warranty period.

 

Again - everyone’s situation is different. Let’s not confuse it.

For the OP - driving in 4HI frequently is rough driving to me - so a cooler may be an upgrade worth considering. The most common reason for a cooler upgrade is towing - but there are others and this is one of them.

Let’s also be honest - at least 50% of late model half ton owners tow nothing heavy nor use their 4wd more than 5% of their trucks drive time. For that half - the mod is nothing more than a pricey cosmetic accessory and overkill. Sure - you can spend $1200 for “piece of mind” in form of a trans cooler, spend about the same buying an extended service contract that covers 10 years and 100k or miles that will cover the trans AND anything else drivetrain - but only provide coverage for a limited time or you can spend less and just go frequent fluid changes/drain and fill the trans and assume a higher level of risk. It’s all up to the individual and their needs. That’s the thing about a forum - what works for one poster may not for the next - there are no “absolute” correct answers. For a majority - the extended service contract gives both solid piece of mind and cost certainty - but your individual mileage may vary.

As to maintenance prior to OP purchase - again, it’s a factor - but my opinion - first this drive train is more forgiving of lax maintenance. No vehicle is reliable without maintenance- but some are more forgiving of less frequent maintenance and extended use. Second - it’s ALWAYS a chance you take buying anything mechanical that something breaks. Only things are how likely is it t break and what’s it cost to repair. Historically - this drivetrain is more reliable than comparables from other makes. Doesn’t mean fail proof - just less prone. Why play Russian Roulette with 3 chambers loaded when you can play with only 1. Likewise - cost of repair - in general Toyota uses more common use components and less pricey tech than others - so more plentiful parts that cost less to produce means lower overall cost.

For the OP - a lot of info here - distill it down and remember it for what it is - opinions on what you can do. A lot of solid posters here - but only you know what fits your needs and budget. Ultimately there is a law of diminishing returns in any maintenance/upgrade you perform. Cheapest are fluids and filters - it gets you the most bang for the buck along with a cheap OBD reader. A trans cooler will give you a lesser chance of trans failure with occasional/frequent heavy use - but it comes at a cost. Personally - if I invest 50k in a vehicle - I say spend $1500 in buying more protection. Of course some people would rather buy something flashier or that gives additional utility versus a “maintenance” upgrade and their choice/there money. Even without it - it’s a solid truck with no extreme reports of failed transmissions. Take a gander at a Ram forum for example and tell me owners can say the same about their trucks WITH trans coolers installed at the factory.