3rd Gen SR5 4 WD operation?

I have a 2016 TRDOR and I hardly ever use Crawl Control or Rear Diff Lock. I do use MTS regularly. The MTS is basically a “variable slip A-Trac” system since there is NO A-trac button. I own some timber property with steep logging roads and some inclines are long enough that with an “open differential” in the rear, without adequate momentum (speed) you can get stuck and have to back down the hill and start over. My son has a 1999 Tacoma and there is no rear locker or A-trac. You basically have 2 driven wheels , one on each axle. In the Gen 3 my understanding and experience is the 4WD LO is open rear diff when MTS is NOT engaged. In 4WD HI the “Trac” system does use brakes to stop the spinning wheel and transfer power to the other wheel which appears (thru the otherwise open diff) to have the least traction. It is thru this method Toyota uses the brakes to keep the wheel with the most traction powered. It’s really a good system. With the Gen 3 you can use the rear locker with NO MTS and I’m usually fine on these steep hills. Or I can engage MTS and it’s even better because you get the wheel with best traction on the front and rear. With the rear locker engaged and MTS you have the most traction with 3 driving wheels with great traction. Except my owners manual says MTS does not operate when rear diff is locked. Some other summaries I have read imply MTS still works on front axle with rear diff locked if under 3mph. Not sure which is correct. I am considering buying a 2023 SR5 4WD, after selling my 2016 TRDOR, and am realizing with no MTS and no rear locker I’ll be back to the 1999 capability like my son’s Tacoma. My 2016 owners Manual describes the features of all Tacomas and it’s my understanding the default status of 4WD LO is “Trac off”. So you would actually have better traction control in 4WD Hi when “Trac” is on. In summary if I get an SR5 (not trail version) I will be getting stuck at my property. Looks to me like the TRDOR is no more expensive than Trail edition. But the Trail edition has some factory lifting but less off road software regarding MTS and Crawl Control. The Trail edition is looks like a good option. I do think MTS is superior to rear locker only but not a bad configuration. If it was only less expensive. Am I correct the SR5 (not the trail version) has no traction control logic in 4WD LO?

 

Idk, what kind of property you have, you'd get stuck in, but i have a fairly nasty at times of the year 2 mile dirt road with lots of large rocks, and deep mud ruts to navigate before i get on the asphalt. Even with a ft of snow, my sr5 in 4wd and decent tires handles it with no problem. Compared to the tundra i had, this tacoma is like a tank. Haven't even come close to getting stuck.

 

I have a 2016 TRDOR and I hardly ever use Crawl Control or Rear Diff Lock. I do use MTS regularly. The MTS is basically a “variable slip A-Trac” system since there is NO A-trac button. I own some timber property with steep logging roads and some inclines are long enough that with an “open differential” in the rear, without adequate momentum (speed) you can get stuck and have to back down the hill and start over. My son has a 1999 Tacoma and there is no rear locker or A-trac. You basically have 2 driven wheels , one on each axle.

In the Gen 3 my understanding and experience is the 4WD LO is open rear diff when MTS is NOT engaged. In 4WD HI the “Trac” system does use brakes to stop the spinning wheel and transfer power to the other wheel which appears (thru the otherwise open diff) to have the least traction. It is thru this method Toyota uses the brakes to keep the wheel with the most traction powered. It’s really a good system. With the Gen 3 you can use the rear locker with NO MTS and I’m usually fine on these steep hills.

Or I can engage MTS and it’s even better because you get the wheel with best traction on the front and rear. With the rear locker engaged and MTS you have the most traction with 3 driving wheels with great traction. Except my owners manual says MTS does not operate when rear diff is locked. Some other summaries I have read imply MTS still works on front axle with rear diff locked if under 3mph. Not sure which is correct.

I am considering buying a 2023 SR5 4WD, after selling my 2016 TRDOR, and am realizing with no MTS and no rear locker I’ll be back to the 1999 capability like my son’s Tacoma. My 2016 owners Manual describes the features of all Tacomas and it’s my understanding the default status of 4WD LO is “Trac off”. So you would actually have better traction control in 4WD Hi when “Trac” is on. In summary if I get an SR5 (not trail version) I will be getting stuck at my property. Looks to me like the TRDOR is no more expensive than Trail edition.

But the Trail edition has some factory lifting but less off road software regarding MTS and Crawl Control. The Trail edition is looks like a good option. I do think MTS is superior to rear locker only but not a bad configuration. If it was only less expensive. Am I correct the SR5 (not the trail version) has no traction control logic in 4WD LO?



^^ I fixed that so it's easier for us to read. You're welcome.

 

If it were me, prioritize the following:

• Good tires
• An air compressor (so that you can deflate the good tires)
• Traction boards
• Shovel

If you are still getting stuck after all of that, then MAYBE consider a locker.

 

Oof! That is a wall of text.

The non-OR 3rd Gens do great off road. TRAC works quite well, but not a good as A-TRAC / MTS. The biggest difference that I have seen is that it takes a bit more wheel speed to engage the TRAC system. But, wheels off the ground is no issue for the SR / SR5 / Sport / Limited.

Ignore some of the bad terminology and crappy test methods:




Also:

https://www.tacomaworld.com/threads/3rd-gen-traction-control-modes-explained.530695/unread​

 

Only times i needed 4lo was pulling my boat&trailer up a slick grassy knoll from the lake.

 

So I have some steep hills with uneven (left to right) undulations. Erosion is a constant problem. When wet it’s challenging. I have Goodyear Duratrac tires and they are much better than the TRDOR OE tires. My son (1999 Tacoma) has trouble climbing these hills unless keeps speed up. My 2016 TRDOR does not have any problems with MTS or locker engaged. When just in 4WD Lo (no locker or MTS) I do lots of spinning but usually get up hills ok. No question the MTS is MUCH better than just 4WD LO. I don’t think there is any traction control intervention in 4WD LO only. However in 4 WD HI TRAC defaults to ON.

 

MTS still operates across the front axle when the rear diff is locked.

The solution to your problem is very simple. Buy an OR/Trail or buy an SR5 and install selectable locker/s. You really come out ahead with the SR5 and aftermarket locker/s if cost effectiveness is high on your list.

 

The price difference between an SR5 and an Off Road in the same configuration is only like $1800, are you really coming out ahead much after the installation of an aftermarket locker?

 

My impression is MTS operates on front when rear diff is locked. My owners manual says neither MTS braking nor TRAC is operational when rear diff locked. It makes sense TRAC and applying brakes to locked REAR axle would not work since wheels must rotate the same rpm. So the Manual is too broad if it still works on front. Since the Trail Edition is no cheaper the TRDOR I would probably just get another TRDOR if I sell my 2016. The 2023s are so expensive I’m having 2nd thought about selling my 2016. I just retired and mine is 7 years old next month and I don’t think I’m gonna like the redesigned model. Also I’m wondering IF systems start breaking on my 2016 it can be very expensive to repair. My thought process is, I like the Gen 3, and if I want to keep one for 7 more years, get a new one and have a new warranty starting over. I can probably get an SR5 for $5000-6000 less than TRDOR. That’s also impacted by my dealer getting TRDORs with leather, moonroof and stuff I wouldn’t order. My dealer is not taking any new orders. I’m not getting many offers for my 2016.

 

At $1800 you aren't coming out ahead. And if that's the difference we're quibbling over this whole discussion is pointless.

 

The OM is a mess for explaining the TRAC functions, esp as they vary depending on the Taco trims. That is why the Traction Control thread was created.

 

The Multi Terrain ABS is disabled (offroad braking feature) but tractive MTS (A-TRAC) is not. At least no one I know of has found that to be the case.

Note TRAC is not specifically A-TRAC or MTS according to Toyota convention.

 

Yes, I have read the traction control thread. I agree the OM does not thoroughly describe the proper operation of the complex features of the TRDOR. I’m positive I have felt the tire slip change sides due to MTS operation on front axle with rear diff locked climbing steep muddy hills. I would have written the manual differently. It is complicated however, in a good way.

 

A-TRAC only comes in the Off Road and Pro with Manual transmission too.

 

https://www.tacomaworld.com/threads/3rd-gen-traction-control-modes-explained.530695/

 

A-TRAC on my 2020 6mt OR is enabled when the rear locker is engaged. I would likely never use the locker if that wasn’t true. 2 axle A-TRAC > rear axle locker. 2 axle locker might be a good option.

 

I looked at that thread. It clearly states that an SR5 has TRAC on in 4LO, unless you turn off VSC. When VSC is off, TRAC is off also. That means you would get the brakes stopping the most spinning wheel at some pre-set (but not variable/selectable) value. The TRDOR defaults to TRAC off when in 4LO. That make sense because you can select MTS which is selectable wheel spin before TRAC intervention. This is a big deal IMO and makes it much better than my son’s 1999 Gen 1 which has no traction control at all. This makes me think even without a rear diff lock you would have great off road capability as long as you had good tires. I am gonna seriously consider an SR5 4WD or possibly the Trails edition. The Trails edition would also have TRAC on in 4 LO. My dealer prices on Trails edition are almost as much as the TRDOR.

 

Keep in mind that TRAC is not the same as A-TRAC/MTS. The later systems contain a hydraulic brake booster instead of a vacuum brake booster plus other things and are more capable. I think of TRAC as a simulated limited slip diff, A-TRAC as a simulated locking diff, and MTS as an adjustable simulated locking diff. I admit those are not perfect analogies.

 

That’s a good pt. I saw another Utube by “the car care guy” who is an ex Toyota mechanic. He is very knowledgeable about Toyota systems. He described the hydraulic booster you describe as being required to run Crawl Control and MTS. The OM even states that protracted use of Crawl Control can overheat the brake system and I believe the truck will temporarily shut down crawl control until it cools off adequately. So the brake pressure oscillations must be demanding. I’m thinking MTS is not nearly as demanding as CC