Stupid Noob Question about 4HI

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You can engage and disengage 4x4 under 62mph. You can drive in 4x4 as fast as you like I tend to keep it under 60.

 

put it to you this way....if you drive mainly on paved roads and are traveling at 50MPH you prob. don't need 4WD in snow or not. 4wd at 50 on a snow covered road is to fast IMO The final drive ratio in 4hi and 2hi are the same. I've driven at 65MPH in 4hi with no problems. I have an 03 and according to the owners manual it says to slow down below 62MPH to shift from 2Hi and 4Hi or 4Hi to 2Hi so i guess you can haul ass without any worries!!!

 

I flip my 4WD on in heavy rainy conditions when I get on the highway. I've gone close to 65mph but not any higher than that. I do that for a couple reasons - peace of mind in rainy conditions (keeps the truck from getting squirrely) and to run it atleast once a month to keep things 'running' and lubricated (so to speak). I only use it in heavy rains and I don't make any turns. As soon as I get off the highway, I flip it back to 2WD.

Obviously, snow is a different story and I have it in 4WD all the time in the snow.

 

109, though I dont recommend it.

 

This is also covered in the owners manual.
For the record I have gone as fast as 70, this was a result of the roads clearing up and traffic speeding up at the same time and I couldn't switch back into 2 wheel drive.

 

If it's iced over I keep it in 4wd. 60-70mph is the norm for icy conditions on the interstate here. If it's wet I would drop it to 2wd you can feel a little bit of pulling and jerking when it's dry enough to be in 2wd. Toyota mechs told me it was better to switch in and out of 4wd when not moving.

 

I'll have to find it again but there's a YouTube video of a guy with a supercharger pulling 13 and 14 second 1/4 mile runs with 4WD engaged. Although I think he's stupid the 4WD system is pretty strong IMO.

As others have said though.. if you're doing under 62 you can engage 4HI however if you need 4WD you should be going a lot slower than that.

 

i have 4x4 on my truck and i rarely use it for highway driving even in bad conditions (have a great set of tires). the only time i use it is on logging roads when needed and the occasional slippery hill/backroad

 

Damage to the transmission isn't the real issue. If you need to be in 4WD because of road conditions, then the collision will cause damage to the truck body if you go over 45! Going 70 in 4WD? Insane!

 

Going any speed won't hurt anything in 4x4, unless your front drive shaft is bent or really out of balance. Although I wouldn't try it. Things will get hot, especially on dry pavement. I don't think you should be driving very fast if you need 4x4 though.