Help me understand H2/H4/L4

Recently bought a 2002 Tacoma
2.7L 4 cylinder 4WD Standard Cab manual transmission. I’m trying to absorb as much information as possible about it. I’ve read some of the previous Tacoma threads on 4WD, so I’m hoping you can help me fill in the gaps and ensure I don’t break anything.

H2 - Always drive in this mode on pavement. 2WD (rear) and is for every day driving. Can shift in/out at speed.

H4 - 4WD but only use in low traction. Mud/snow/dirt but never on dry pavement. Can shift in/out at speed.

L4 - Crazy terrain, rock climbing, deep mud, etc. Likely won’t need it as a newb. Ensure you’re stopped and in neutral first.

N - What would happen if you drive in N for the 4WD shifter?

Thanks for the help and helping me learn.

 

Couple corrections.

H4 is limited on maximum speed to engage/disengage. IIRC, the speed is about 60 mph.
There is a mythconception about dry pavement. Yes, you can drive on dry, but it is not recommended. Tight turns will cause the drive train to bind. In truth, it is recommended to drive about 10 miles each month in H4 to keep the system lubed and functioning.

N is for NEUTRAL. No gears are engaged. You can not drive in N. You could roll downhill.............

 

You’re pretty close.

I’ll add that with the MT you can shift into 4L while coasting slowly with the clutch in. I find it to be smoother this way. 4L is especially good for extra control as it gives you a much lower overall gear ratio which makes engine braking more effective.

with 4wd shifter in N you will go nowhere as the transmission is disconnected from the driveshafts completely.

 

I may still be feeling out the 4WD shifter because it felt like I was in neutral, but in gear on the standard shifter of course, and it still drove. Although the 4WD light was on so I was likely in H4? Need to get tighter with shifting that gearbox.

For H4 is it okay to drive around town in snow then? 10 miles a month I can do, especially with snowy and slippery conditions

 

H4 is fine to drive in low traction like snow or dirt.

Only consequence to h4 on dry pavement would be difficulty steering due to driveline bind and higher wear on tires and the driveline components. I've seen people break CVs with extreme (1,000s of miles) driving in h4 on dry pavement.

Keep in mind that driveline bind is not going to break a healthy driveline. Moab Utah is basically sandpaper rocks and people drive on those with 4wd and 35" tires. the tires will "bark" as they break traction and slip the tires on the rocks. I can't imagine a more traction rich environment that is frequently driven in h4.

 

ELI5
H2 - daily driving, forest service roads, etc
H4 - forest service roads, snow, slippery, wet. (you won't hurt anything if you drive on dry pavement for short periods, but don't make a habit of it)
L4 - Same as H4 plus much more difficult terrain. The lower gear gives you more control and power when the going gets rough. In L4 little movements of the gas peddle have less effect on the vehicle.
N - Used for towing the truck with all 4 wheels on the ground.

 

for short distances at low speeds only

 

We had someone posting here within the last year or so who grenaded most of their driveline because they had mismatched front and rear tires (diameters were different between front and rear axles). IIRC, this occurred during straight highway driving, albeit for a long distance.

 

I was taught to keep in 2H on snowy roads so I wouldn’t overdrive conditions. Many people get overconfident due to how well they can keep going in 4wd and then get in trouble when they let off the gas or hit the brakes. I used to live in some snowy territory and it always seemed you’d see four wheel drives sliding off the roads on downhills and sharp turns.

Of course when the snow gets deep or you are dealing with really poor conditions 4H is fine.
That’s my opinion anyhow, probably worth less than you paid for it

 

Exactly, thus my "healthy drivelines" comment.

 

I was similarly taught that 4wd can get you more stuck than 2wd, with nothing to fall back on (unless you have recovery gear). If you don't drive like you're looking for trouble, then 4wd can make life a lot easier in snowy conditions.

 

Agreed. The scenario I posted might not occur to everyone, despite how plausible it may be. There are probably lots of folks driving old beater trucks with mismatched tires.

 

^This^

I've seen a lot of broken trucks while wheeling around Moab. The biggest single cause of carnage is the gas peddle. Dingle berries will get into hard spots and just give it the gas which IMO is the worst thing to do. Invariably 75 - 100 pounds of tire and wheel will get into the air, start spinning at fast, then stopped instantly when it touches the ground. All that energy has to go somewhere and something always breaks.

Not using 4wd in snowy conditions seems to be bad advice to me. In 2wd the truck will want to fish tail and and spin out. With all 4 wheels pulling the truck will go wide which is easier to recover from. Besides 4wd/awd cars and trucks are a dime a dozen now days. Over confidence is rampant in snow storms, which is why I do everything I can to avoid the first Darwin storms of the season. (A Darwin storm is when the idiot, over confident drivers remove themselves, and usually somebody else, from the driving pool.)

 

"Don't drive like you're looking for trouble." You sir have provided me with my new advice for anyone driving anything, anywhere. Thank you. I was taught the same thing. It's good advice for those that think 4wd is some magic that will let them go anywhere. On the other hand I put my truck into 4wd whenever the road conditions allow, and drive right over obstacles that would stop me dead in my tracks in 2wd. Not getting stuck in the first place is the best policy. If I start getting stuck in 4wd, I'll stop right there and evaluate my options before proceeding. Without knowing it I don't drive like I'm looking for trouble. I love it.

 

I have to confess, when I first wired up my Hella horns, I had a hard time following my own advice. I really wanted to try them out on someone who "deserved it".

 

I have to admit my advice to stay in 2wd until 4wd is necessary is biased due to years of driving Tacoma five lugs and similar vehicles in snow country. ( I used to live ten minutes from a Western MA ski area) I’ve seen my share of new four wheel drive owners sliding off the roads in that area. I’ve had cars following my rwd pickup hit the ditch and roll over on roads I had no issue on.

That said, once a driver is used to how their vehicle handles in snow, they’ll be able to choose appropriately for the conditions.They’ll know when to lock it in. And there are times 4wd is called for.

 

the max speeds for different gears in h2,h4,l4 are listed in owners manual

 

Nobody mention L2 position. Only available with trucks with manual locking hub. It powers only rear wheels with high torque. I use it for towing heavy stuff (like fallen trees) on hard surfaces. Can make sharp turns without binding and still benefit from high torque provided by T-case.

 

Advice like this is why I don't like to buy used 4X4 vehicles. Yes, you can get away without breaking stuff if you drive in 4X4 on areas with good traction, for a while. But just because it doesn't break today doesn't mean you didn't do damage.

Most of the time you simply overstress components and the damage shows up later but it is possible to do catastrophic damage right now. The guys driving highly modified rigs at Moab and other places see parts breakage far more often than typical users. If you're gonna play, you gotta pay. If you want to keep the truck for years and put 400,000 miles on it don't drive in 4X4 on pavement unless absolutely necessary and limit the time as much as possible.

I've personally had to have transfer cases rebuilt twice and I've seen others do serious damage by doing this. And it took surprisingly few miles of 4X4 operation on pavement. In my case I purchased a used truck where the vacuum lines had gotten reversed on the transfer case prior to me buying it. I was in 4X4 when the switch was in the 4X2 position. I was right out of high school and smart enough to know not to drive in 4X4 on pavement, but not experienced enough to recognize the problem until it broke, twice. Just don't do it. The risk isn't worth the reward

 

Well, there is no “L2” position for our trucks (and def not on the OP’s 2002). It’s just 4L with the hubs unlocked.


I use mine all the time the same way. Crazy useful moving trailers around in tight spots