Use 4h on highway about one hour, is that hurt anything?

If something broke you would know right away ( broken CV or axle shaft most likely) . If it still works it’s cool. It’s like if a really fat person sits in a chair . Either he broke it , or he didn’t and people can keep sitting on the chair.

 

Where’s that link of the guy who's wife grenaded the differential driving in 4wd on a dry parking lot and he asked why the warranty repair was denied when you need it?!

 

Just because it isn't broke now doesn't mean you didn't damage something. The damage from stuff like this is cumulative. A fat guy can sit in a chair for only so long before it eventually breaks. A skinny guy can sit there a lot longer before it breaks.

Just about everyone I know with a 4X4 has done something similar, but not for 80 miles. Unless you felt binding it is unlikely that you'll see a catastrophic failure any time soon. But you did over stress parts and they will fail sooner than they normally would have. If you're like most people who trade often it will probably be the 2nd or 3rd owner who pays for the damage though. This is why I really don't like to buy a used 4X4.

If you are in a high traction situation in 4X4 and turn the wheels sharp then you stand a good chance of blowing up something in the transfer case or front diff. If you're lucky you'll break a U-Joint before something more expensive blows up. But what you did is more likely to stress the chain in the transfer case. Over time if it is over stressed it will stretch and eventually start slipping on the gears when you accelerate.

The chain in your transfer case

 

I have done many times forgetting to take it out of 4H but then realized the light on the dash indicating it was in 4H. Now if that 4 L then you are in trouble but I doubt you could go 80 MPH maybe 20 if you are lucky but you would know.

 

My truck never comes out of 4H all winter long (around 5000 miles) I drive 70mph on solid ice roads, make full lock turns, etc never had any problem whatsoever come spring time twist the knob & it's now in 'summer mode'

It's a Wyoming thing if I have to explane it you wouldn't understand

 

I was going to mention that too that if you live in the North Snow Country like Canada and parts of the U.S driving in 4 H is normal during Winter months unless you get nice clean roads then it goes 2H .

 

Part out!

 

Yeah 3rd gens do that too. I think the threshold is 100 kph, so maybe you can turn on 4wd up to 62!

 

You're fine. The tires did the slipping so your gears and transfer case chain didn't have to.
I did the same thing yesterday after getting off a flex ramp. Forgot I was in 4low and wondered why the 35s were chirping as I backed into a parking spot.

 

@80 MPH you're not in 4wd anyways so it doesn't really matter. It drops out at 60ish or so. Highways lack tight turns so even if you were in 4wd it wouldn't matter. I turn mine on on long straight drives occasionally anyways.

 

Truck is likely still fine, but at that speed you can bet it didn't do the 4wd system any good either.

 

Kind of think the system has more strength then the tires have traction. Ever accelerated fast enough to spin the tires?

 

I know 4wd won’t engage over 60mph. Is there an indication that its dropped out if you exceed that? Annoying ding? Flashing 4wd indicator?

 

There's no indication because it doesn't "drop out" at any speed. The only restriction is performing a 2HI to 4HI shift above about 62 mph.

 

This is incorrect.

 

No

 

Anything is possible but it's highly unlikely. The drivetrain isn't indestructible but it's fairly stout. I wouldn't sweat it for a second.

 

They are engineered for those types of stresses, including probably while hauling a load or pulling a trailer. The case in my earlier comment was about a post where there was leaking oil and holes in the guy’s differential. It was most likely due to his wife gunning it to get off ice in a parking lot and while doing so it hit dry pavement all while she was turning. The funny part was he was trying to get Toyota to cover it.

 

When off road, loads through the drivetrain are typically lower because of tire slippage. There are always exceptions and thing like bouncing on steep climbs and similar will spike torque loads through the system, but usually low traction surfaces result in low loads on the system.

 

Straight out of the owner's manual:

BUT ALSO


You're supposed to be engaging 4x4 once a month according to your owner's literature.

Regarding wear on the components from driving perfectly straight on the highway, that's like saying you've overstressed the brakes and torque converter by driving the car, best not to use them to avoid wear.