New trucks and 4low...

[DaveInDenver]

I had an 04 4Runner like described above. The only issue was you could not turn the traction control off. There was a work around some out to do this but then a bunch of lights would be on in the dash area.

We had an 2005 SR5 4Runner V6 for about a year and a half. There was a VSC disable button on the lower left dash. I don't remember if 4WD High would disable it automatically or not but you could turn it off until the next key cycle in any mode, 2WD or 4WD Auto.

 

[F8LZ71]

To clear up any confusion with the GM 4x4 and Autotrac systems...

1. The 2 speed transfer case equipped trucks can run in 2wd, Auto4wd, 4Hi or 4Lo.
2. When 4Lo is selected VSC and Traction control are automatically turned off. (some models)
3. Off-road specific models like the Colorado ZR2 and Bison come with electronic locking diffs front AND rear instead of the G80 auto locking rear diff found on Z71, Trail Boss, AT4, All-Terrain or any other model with the tow package installed. (Midsize and 1/2 ton).

 

[RoyJ]

Whether or not I use 4Lo highly depends on the transmission I have in the truck:

• In my old 100 series, it's geared relatively short, and I do not need 4Lo (I do not rock crawl)
• In my 1999 V10 Dodge, the 47RE is ancient with 2.45:1 1st gear. With a Bigfoot camper, I'm in 2Lo (vacuum actuator mod) as soon as I hit logging roads. It allows me to drive in 3rd or OD with the converter locked, less heat in the tranny
• In my Ram 1500 8 spd, I've never used 4Lo. Partly because of teh 4.7:1 1st gear, partly because it's a pavement queen...

 

[shade]

That's where the knucklehead in the operator's position has to predict things. You want to shift on the fly into 4WD before you need it so you don't slip. It's why I think there's more accidents now on snowy roads (the invincibility effect aside). All auto 4WD or AWD systems are reactive, you're already starting to spin and the system is trying to unf*ck things. If you're a level headed driver (as we all are, no doubt) and knew when to go in and out of 4WD you never need the traction control to do it for you. Naturally you also drove circles in parking lots on snow days to get the feel of your truck and know how if you have engaged 4WD and are still starting the spin or drift you knew how letting off the gas and steering would get you straight again. Of course now the car does all of this for you so you never learned nor practiced. So as long as your particular spin matches the designed parameters it works. When it doesn't, welcome to the ditch!

I routinely see 4WD/AWD vehicles making off-pavement excursions in the winter, most likely because they're overdriving the available traction when turning or stopping. On winter roads where ground clearance isn't an issue, I'll take a FWD econobox with proper winter tyres over anything else on all-season meh tyres.

To clear up any confusion with the GM 4x4 and Autotrac systems...

1. The 2 speed transfer case equipped trucks can run in 2wd, Auto4wd, 4Hi or 4Lo.
2. When 4Lo is selected VSC and Traction control are automatically turned off. (some models)
3. Off-road specific models like the Colorado ZR2 and Bison come with electronic locking diffs front AND rear instead of the G80 auto locking rear diff found on Z71, Trail Boss, AT4, All-Terrain or any other model with the tow package installed. (Midsize and 1/2 ton).

For clarity, does "electronic locking diffs" = a fully locked differential, that uses an electrically actuated locking mechanism? I ask because the use of ABS-derived, "LSD-ish" features have become popular, so I can see something similar being promoted as an "electronic locking differential".

 

[MOguy]

We had an 2005 SR5 4Runner V6 for about a year and a half. There was a VSC disable button on the lower left dash. I don't remember if 4WD High would disable it automatically or not but you could turn it off until the next key cycle in any mode, 2WD or 4WD Auto.

View attachment 526995

With my 4Runner you had one system that would control the engine and how much power it would deliver to Wheels if there's wheel spin and then you had another system with the brakes.

Not sure about the 2005 but with the 2004 you could only disengage part of the traction control, but there were still issues with the engine controlling wheel spin. I think yours is the same, you're only turning off part of the traction control. But I might be wrong. Mine wouldn't even let me do donuts in the snow. With the Tacoma you could completely turn off all the traction control

I was fine with it, it was my grocery getter, pull the trailer, go camping with the family vehicle. I didn't do off-roading with it anyway, I have the Wrangler for that. The 4Runner did do well as a winter vehicle. I had Super Swampers on my Wrangler, it was dangerous in the winter.

I really liked the 4Runner until it had head issues at 165k. After that I kind of lost faith in Toyota. I know the head issue was only with the early 4.0 but I got stuck with one so I'm a little bitter.

 

[F8LZ71]

For clarity, does "electronic locking diffs" = a fully locked differential, that uses an electrically actuated locking mechanism? I ask because the use of ABS-derived, "LSD-ish" features have become popular, so I can see something similar being promoted as an "electronic locking differential".

Yes, true locking diffs. No gimmicks.

 

[Highlander]

4 auto is basically 4 Hi. It is engaged by a computer when it detects, through the sensors, a slippery surface. It house into 4 hi automatically. I don’t like that to be honest. I prefer doing myself.

I remember I had trouble to understand how the LR central differential works and one guy, a farmer from Scotland who run a 93s Defender, told me “ do you know how a rear diff works? “ I said “yes” and then he said “ well, imagine a rear differential rotated by 90 degrees that spins tow driveshafts instead of axels”. It made a lot of sense

At this time, the best 4wd in the market is available on Toyota LC 200 and G wagon. IMHO.

 

[MOguy]

4 auto is basically 4 Hi. It is engaged by a computer when it detects, through the sensors, a slippery surface. It house into 4 hi automatically. I don’t like that to be honest. I prefer doing myself.
...

No it isn't.

Regular 4wd drive will offer the same split front to rear. AWD, 4auto, Full time 4 wheel drive... all have some sort of "transfer case" that allows the ratio of power to change from front to rear.

 

[XJLI]

Plenty of full-time and 4 auto systems out there, ones with electronic helpers, or clutches, or gerotor couplers, or viscous fluid, open diffs, whatever.

If the ability to mechanically lock (via lever, dial, or button) 50/50 isn't available, it's useless. It makes me pretty sad that GM moved to the same BS kia and Hyundai put in there SUVs that aren't real two speed transfer cases. Anything without that ability will fail on the trail, 50ft in or 5 miles in. Even the wonderful ATRAC diffs will overheat and turn itself off if you beat on it; can't expect some half ass attempt of that from GM to work as well, and I'm a Chevy guy.

 

[DaveInDenver]

If the ability to mechanically lock (via lever, dial, or button) 50/50 isn't available, it's useless. It makes me pretty sad that GM moved to the same BS kia and Hyundai put in there SUVs that aren't real two speed transfer cases. Anything without that ability will fail on the trail, 50ft in or 5 miles in.

I don't think it has to be all that dire. Plenty of vehicles do just fine in light trail duty. Subarus for example can be quite capable on mild dirt roads and light 'wheeling. The Subarus back when we still got 2-speed cases were danged good. Those were cool.

The main issue I feel is when you don't have solid, simple mechanical connections the heat build up can get to be an issue in viscous couplings and traction control when pushed hard. So it's just a matter of expectations. It's been beat to death but it's true, what works well on harder technical trails isn't nearly as ideal as getting to a ski area in winter. Different tools for different jobs.

Even the wonderful ATRAC diffs will overheat and turn itself off if you beat on it

A-TRAC are just open differentials, it pulses the brakes using the ABS system to prevent wheel spin. You might lose the limited slip if A-TRAC fails but the truck will keep running. Now whether it's wise to work your brakes that hard, well, I'm not sure.

 

[shade]

I don't think it has to be all that dire. Plenty of vehicles do just fine in light trail duty. Subarus for example can be quite capable on mild dirt roads and light 'wheeling. The Subarus back when we still got 2-speed cases were danged good. Those were cool.

The main issue I feel is when you don't have solid, simple mechanical connections the heat build up can get to be an issue in viscous couplings and traction control when pushed hard. So it's just a matter of expectations. It's been beat to death but it's true, what works well on harder technical trails isn't nearly as ideal as getting to a ski area in winter. Different tools for different jobs.

A-TRAC are just open differentials, it pulses the brakes using the ABS system to prevent wheel spin. You might lose the limited slip if A-TRAC fails but the truck will keep running. Now whether it's wise to work your brakes that hard, well, I'm not sure.

All true. My old Subaru was a beast on anything I drove it over, and it had one of the simpler AWD systems; open diffs front & rear, with a fulltime 50/50 viscous center diff. Otoh, I would never try taking it on the same trails as my truck.

I tire of seeing A-TRAC and the like bagged on for not being what they aren't, and of A-TRAC fanboys saying it's just as good as a locking differential. A-TRAC works very well in shorter applications while traversing an obstacle. Used too hard for too long, and it overheats the brakes. It's also a poor substitute for a locker in some situations, just like a locker isn't always ideal. It's not magic or the devil.

 

[MOguy]

what works well on harder technical trails isn't nearly as ideal as getting to a ski area in winter. Different tools for different jobs.

yep!

 

[luthj]

50/50 torque splits with a differential are not the same as classic no center diff 4x4. The latter will allow one axle to spin, thus torque is limited by the spinning axle (unless abs/traction control is available). With locked/no center diff 4x4 both driveshafts must spin at the same rate -always-. The torque split can vary from 100 to 0% depending on wheel traction.

I personally think is great there are so many different configurations available across the vehicle range. It may mean you can't get the exact model/package you want with the 4x4 system desired, but there will always be a decent option for all but extreme usage cases. It may require looking outside a specific brand for those loyal to one ecosystem.

 

[shade]

I personally think is great there are so many different configurations available across the vehicle range. It may mean you can't get the exact model/package you want with the 4x4 system desired, but there will always be a decent option for all but extreme usage cases. It may require looking outside a specific brand for those loyal to one ecosystem.

To prove your point, there's even an AWD Prius available - with no center differential. It's a weak system, but it puts some power to the rear.

I'd still put winter tyres on it, though.

 

[DaveInDenver]

I personally think is great there are so many different configurations available across the vehicle range. It may mean you can't get the exact model/package you want with the 4x4 system desired, but there will always be a decent option for all but extreme usage cases. It may require looking outside a specific brand for those loyal to one ecosystem.

So to whomever is selling a small truck with a stick shift and manual transfer case - shut up and take my money now!