Well, the weather isn't that great here at the moment, and I was wondering about highway driving in 4Hi. I've driven on ice and snow in 4Hi before, but usually never over 40mph. Well it's real wet and cold down here (at lease for us lol) and I'd definitely like the added stability of drivin in four wheel drive, but traffic's pretty light and cars are still drivin 60mph+ (lucky them with their 4 wheel brakes, traction control, and abs and whatnot), so I'm just wondering if it's safe to drive an older yota in 4hi in speeds in excess of 50-60mph?

 

I usually drive in 2wd as much as i can. i have heard dont go over 50 or 55 in 4wd but i dont think my truck would do that if i tried. I think you will be fine just watch the dry or just wet spots.

 

no clue...i know i read in a manual somewhere that there isn't a problem mechanically with driving in 4hi that fast but i guess it is personal prefrence

 

No problem driving fast in 4H or 2H with the front hubs locked, conditions permitting. Just pop out of 4WD any time you get onto bare pavement and pop back into 4WD when snow/ice covers the road. You just want to avoid 4WD on bare pavement if possible.

 

Well, I don't think hitting any dry patches will be a problem today lol. But yeah, I definitely want the extra traction afforded by 4wd today, seein as how I tend to hydroplane on a whim, and have my rearend swing out on me even on dry roads with my back diff locked lol.

I knew that you can shift from 2wd to 4wd on the fly with electronic engaging 4wd, but how bout mechanical 4wd shifter? Just throw it in neutral and pull it down into 4wd? I know that you have to come to a complete stop for 4lo, and I assumed it was the same for 4hi. Just never tried cause I figure better safe than sorry lol. Oh, and do manual hubs make a difference? Thanks!

 

I drive between 60-70mph in 4HI without any problems.

As long as you're going straight when on dry surfaces 4HI should be ok.

 

Just grab the t-case shifter and push it forward for 2H and pull back for 4H. No clutch needed, just do so when going relatively straight and not while spinning or under heavy acceleration ro braking load. This is assuming you have the front hubs locked.

 

I scanned this page out of my 95 owners manual a while back... This is a common question believe it or not.




When I used to drive the interstate I would do this from time to time when it really rained hard and I never had a problem. Only thing that sucked was that I would run out of horsepower at around 55mph when the road was flooded.


The piece of mind is well worth it though. One night I drove through at least 8 inches of standing water on I75 at 55 and tracked straight and true in it with my 11.5" tires.

I wouldn't worry about driving in H4 on even dry pavement either unless you locked the front end. In its stock form its an open diff and it won't hurt anything but your gas mileage.

 

you can drive "normal highway speeds" in 4wd, however you shouldn't be driving that fast in 4wd. If its slippery slow down! 4x4 is not an excuse to drive the speedlimit in bad weather.

If the issue is indeed patches of bad weather just leave the front end locked in, and switch back and forth on the fly. I personally like to ease off the gas to eliminte strain on the front end componets, but its probably not needed as long as you're not flooring it.

 

that posting above suggests that you shouldnt do it above 25 mph. that seems a little low compared to the 50 mph or so that i often see around here but regardless, its not the best idea to shift into 4H going 60, slow down some and get a steady speed and shift it. you wouldnt wanna put too much torque on the t-case, though both ends of the tcase should be going the same speed provided your hubs are locked. just remember, 4wd doesnt give you any better stopping power

 

Why not?

If its safe to drive the speed limit it's safe to drive the speed limit. We drive more capable vehicles for a reason.


And the truck is more than capable of doing it, so why do you say not to?

 

see above: 4wd doesn't improve stopping power. slippery road = no traction which is helped with 4wd, but slippery also = no traction during braking, which is the same regardless of 4 or 2wd. you might be able to drive faster than everyone else but you can't stop any faster.

 

ever wonder why so many soccer moms end up in ditches along the side of the road?

 

how do you blind a soccer mom..?








put a windshield in front of her face.

 

Just because you have 4x4 that helps with handling in slippery conditions, doesn't mean the truck will stop any faster than a 2wd will.

 

It centainly helps with no rear brakes. Little technique alot of us like to use called downshifting.

Seriously though, if downshifting uses then engine to slow the vehicle, 2wd only grabs the rear driveline, while if you have 4wd engaged it'll slow both the front and rear drivelines.

 

seriously, in california, where we rarely see rain, everyone forgets how to drive in it.

ive seen so many accidents that could have been avoided if the people were going slightly slower. all wheel drive is wonderful in the rain, and 4wheel is too, just not as much. personally, id keep it in 2, go slower (who cares if you get there 10 minutes late, at least you get there...) and most importantly, always keep vigil for those idiots that dont know how to drive in the rain.

as for the question for whether or not you can use 4hi on rainy streets. yea sure. just dont get trapped in thinking that it will increase your wet weather performance, thus allowing you to go the same speed as you would on a dry road.

 

It doesn't seem to me that you'd get enough slippage on rainy streets to warrant using 4x4.

 

Haha, well when you factor in tires that are highly prone to hydroplaning, a shorter wheelbase, and a locked differential, you fear every puddle and rain slick road at any speed. It's not that I want to go faster, it's that I enjoy not inducing a spin or having my rear slide out from under me every time I make a turn, or having no steering when I drive over a puddle.

 

I can't argue with that logic at all...


It should be noted however that 4wd does increase the performance of the vehicle, just not the braking. At high speeds such as on an interstate, stability is far more important than braking, but logic dictates that you should never exceed a speed that you can't safely brake from. If visibility sucks, slow down.