Shifting into 4H.

My Tacoma spends a lot of time blinking at me. It probably is the most finicky system I’ve ever owned. I’ve owned Rams and Jeeps that didn’t seem to be this picky about going in and out of stuff. The rear locker is probably the most finicky. Conditions seem to have to be perfect. Just what I’ve observed so far.

 

Hehehe time to part out. Call dibs on the rear end and front axles.

 

have it checked out by the dealer,,, many other's and mine are not at all.

 

Technically it should shift into 4X4 at a stop, but if the gears in the transfer case are not perfectly aligned it won't make the shift until they line up. If the wheels are turning it will engage in less than one revolution of the wheel when everything lines up. I prefer to make the shift to 4hi when the truck is moving. It will rarely make the shift under load. Letting off the gas and let it coast for a few seconds will usually do it.

Low range is different. The owners manual says come to a stop, shift the transmission to neutral, Or depress the clutch all the way to the floor with a manual, then make the shift. Once again it just works better if the truck is moving SLOWLY. As in 1-3 mph. There is an even greater possibility the gears aren't aligned when going to low range and if the wheels turn very slowly it will engage when everything lines up. But it has to be real SLOW.

Owners manual says about 10 miles/month. TECHNICALLY as long as you are in a straight line you won't break anything on pavement, but I don't know any places where I can drive 10 miles in a straight line.

I strongly advise NOT driving on pavement in 4X4 or any other surface with good traction. Find a gravel, or loose dirt road to do this. And there is NEVER any reason to be in 4X4 at 60 mph. If you can safely drive over 25-30 mph you don't need to be in 4X4. It's doing more harm than good at those speeds.

This is why. Inside the transfer case is a drive chain that transfers power to the front axle. If you drive on pavement or any surface with good traction it puts the entire driveline in a bind. The chain is the weak link. They rarely if ever break, but over time they do stretch. Once that happens you press on the accelerator pedal one day and the chain will slip on the cogs when under load. It isn't cheap to repair. BTDT twice.

 

To move into 4L you have to be in neutral right?...

I'm not sure of the proper procedure ( what's ok and what's not ) moving to 4H - I've done it going slow, like under 30 MPH.

I'll check with my 'shop-dudes' next oil change - these guys live for Toyotas.

 

Wisdom.

See the quote above. Teach a man to fish. RTFM my dude.

 

I think the manual states not to shift into 4wd over 50 mph, or something like that. But, when you do, straight line, no load, until the light is green. Ski

 

"On the Fly" is the correct term, and you can use 4hi in any inclement weather, including rain, where slippage can occur.

 

I've done this in wet-weather...on a straight-away of course at 50mph or less.

Better traction is the result as compared to "not engaged"...I've tested both conditions.

 

2HI <=> 4HI can be done on the fly up to like 65 mph
4Hi <=> 4LO must be done while sitting still and not in gear

The instructions are in the owner's manual and also (I think) on the visor.

 

So doing 70-75 in 4HI is not advised? Like I did on the way to work this morning? There was black ice on the bridges and yes I slowed down in sketchy areas but I accelerated to normal speeds on straight and semi straight runs. I been thinking what’s the speed limit for 4HI…? I don’t remember seeing it in the manual. I didn’t want to unnecessarily shift in and out so I just leave it in on icy mornings. Am I doing it wrong or…? Serious question. Not being a smartass. I’ve driven Fords and Chevys at high speed in 4HI without damage. Just wondering if this is not good practice. Got about a 50mi commute mostly highway.

 

Wouldn't the spinning and grabbing of tires while in low range on a slippery road or rocky trail be more detrimental to driveline than the torque created while turning on dry pavement while in 4WD? I don't know, just asking the question.

 

Probably not advised. However, if you can safely achieve 70-75mph then being in 4Hi is unnecessary, so switch it out on the hwy. I don’t think you’ll hurt anything by activating/deactivating your 4wd as required.

 

Yep goodies in tharr need ta meesh

 

Just use it when you need it on the fly. It just works. No need to overthink it.

 

You are fine. I’ve read that the truck will not transition from 2hi to 4hi above a certain speed but I’ve never experienced it. It’s very common in areas with snow to switch back and forth at hiway speeds.

For the most part, a modern car with an automatic transmission will tell you if you are doing something stupid. The goal of automobile engineering is to eliminate the weakest link: the human. It the future cars might be the overlords.

 

It will not shift past 62 mph, it will just beep until you turn the knob back. You can go whatever speed you want once you’re in 4wd. I was testing rear driveshaft vibes and removed the rear driveshaft as part of that. Took it to 85 mph on the front diff and it ran perfectly fine.

 

It's fine and you can run 4HI as fast as you want, there's no limit based on being in 4HI. I don't agree that there's no use to 4HI above some speed. Run it as you see fit.

The truck will reject a 2HI to 4HI shift above about 62 mph but not a 4HI back to 2HI shift.

 

Thank you. This reinforced the advice I recently was told by my dealer service manager and a friend who races off road. They both said to send it. As long as the gears allow it fine. The worst thing could happen is cooking a u joint if turning rediculously on dry pavement. Most people who don’t want me to go fast in 4WD haven’t navigated a mountain pass with 20 foot drifts. I drive fast. Not only to use the vehicle to its potential but to get where I’m getting with max efficiency. Sucks for the folks who can’t fathom why someone drives fast but that’s why we were not created equal. Get outta the left lane. I got places to be. If I wanna eat ditch dirt it’s my prerogative. When I blow by someone and they hit the brights at me they need to decide wether they should get safely to where their going instead of freaking out about what I’m doing