How do I use 4WD and not destroy my truck?

Hi all, I've googled and searched here but can't really find answers to my concerns. I'm probably overthinking things but would rather have peace of mind. Recently got a used 1999 SR5 4WD. Never had much experience with 4WD.

So, how do I use the 4WD without destroying something?

1. I understand tight turns should not be made in 4WD. Will my turning radius be restricted or will I physically be able to turn tight and end up grinding something up?
2. What's considered a "safe" turn? 45 degrees?
3. What about with lockers on? Should I turn even less?
4. Does this apply anywhere or only on flat, smooth surfaces? I.e. If I'm on a bumpy, soft, sandy road, can I turn any tighter?
5. The manual says can go from H2 to H4 if under 25mph. I tried that once at about 5mph and got a terrible grinding noise. Is something wrong?

Thanks for your patience and humoring my anxiety!

 

Basically, just don’t use it on hard surface with good traction. i.e - pavement.

You can use it on dirt, gravel, sand, mud, snow. The sharper the turn, the more the truck will “fight” you in the turn. Is just how the system works.

Same thing goes for the Locker.

 

Don't use 4WD on asphalt or Concrete. Lockers put your rear diff. as a Posi Traction rear end. Use 4WD on like was said, loose terrain, mud or snow. It lessens the strain on the gearing. As far as the grinding, stop and put it in 4WD, as far as it being damaged....I have no clue.

 

To be safe, check the fluid in the transfer case and both axle housings (if you haven’t already). If the grinding noise persists then I’d take it to a pro.

 

Key word being on “dry” asphalt. If it’s slippery don’t risk ending up in the ditch, it’s okay to put 4wd on rainy road. You will definitely notice when your truck is not happy with what you’re doing

 

Ok, so if on asphalt or concrete, J

But on asphalt on a rainy day, I assume I still don't want to be making tight turns right? Is a 90 degree turn on to a street too much?

 

Yeah, don't make that turn with 4WD engaged.

 

I read this as 'WD40' instead of '4WD' and was very confused

Find some forest service roads, throw her in 4wd and play with the hi/low and rear locker features. As long as you're not making slow and tight turns on grippy dry pavement you'll be fine. I've kept my truck in 4lo on smooth rock trails for miles making turns and been fine.

Binding is very noticeable and you'll feel it if it happens. If it does, don't force the truck through it.

 

Assuming you didn't get an owners manual with your purchase, they can be found in PDF form, legal and free, on Toyota websites. Could be useful.

 

Definitely NO 90° turns in 4hi! Way way way too tight of a turn! Even on wet roads it's kinda iffy to turn in 4wd. Long slight turns in 4wd aren't bad when theres some snow.

If you try to turn tight and your locked in 4wd you will feel it binding and fighting you. That's bad! Basically if it's fighting you it's binding and that's when things break. You'll know when it's not okay just by how it feels.

 

On a rainy slick road, I would just slow down. On ice, yeah 4WD. Off pavement, no issues.

I know some here say no problem on pavement if you dont turn, but it's not the way I was raised.

 

Big difference if you have Manual Hubs or the ADD system which do you have??

It comes down to when in 4Wd your tires need to be able to slip.

If they can not slip it creates Torque Bind given enough torque bind things will break .

If your lucky it will be something low cost if not get ready to open your wallet.

 

I try to make a habit not to make sharp turns (where you get close to full lock) in 4wd period. Even offroad when it's feasible i think it's better to reverse/forward a couple times to make a sharp turn more gradual than come close to full lock and take a chance of binding things up. I've experienced binding even making a sharp turn on dry snow in a parking lot lol. I never bother with 4WD in the rain on wet pavement... just good tires and a safe speed. I only engage on ice/snow/dirt/gravel.

 

Manual front hubs. Sounds like from all the advice here is just engage on off-road/snow conditions and as light turns as possible!

 

Regarding the 2H to 4H grinding, hubs need to be locked and then you can go 2H to 4H and back at pretty much any speed. If hubs are not locked and you are moving, the front diff is not spinning, so you need to be stopped to switch into 4H or there will be some major grinding.

 

If you are on dirt or snow you can do all the turning you want in 4wd. Don't worry, it's a pretty durable system. You have to really abuse it to hurt anything.

 

The manual does state to engage 4H from time to time so it doesn't seize up. For the majority of people, that will have to be done on pavement. I personally engage it only when going straight for about a mile and then I turn it off.

 

If pavement is your only option wait until it's wet for some slippage.
Also from the manual...

H2- use this for normal driving on dry hard surfaced roads.
H4- use when you experience loss of traction.

Under Tips for driving in various conditions...
"Four wheel drive models-Toyota recommends not using four wheel drive on dry-hard surfaced roads."

From Toyotas four wheel drive systems website...
"Drivetrain Binding on Dry Pavement... The way a part-time 4wd system is designed both front and rear axles rotate at the same speed when 4wd mode is engaged. This splits power at 50% front and 50% rear. On dry pavement this will cause the drivetrain to bind when vehicle is attempting any type of turn. Drivetrain binding causes severe strain on various 4wd drive components. Therefore 4wd mode on these vehicles should only be engaged in slippery conditions such as off road driving and poor road conditions."

From Toyota four wheel drive system explained (Tacoma HQ)...
The Tacoma – like a lot of pickup trucks – uses a part-time 4WD system. The front differential locks, which means that the Tacoma’s 4WD system should only be used on surfaces with limited traction. Using the Tacoma’s 4WD system on dry pavement should be avoided, especially if you plan on taking any turns.

From 4X4abc.COM (see below links)...
The terms used differ from driveline wind up to axle bind, axle wind up and drive line bind, but fact is, that you can not use part time 4WD on dry high traction surfaces. Period. You'll get drive line windup. This has been known since the invention of 4WD more than 100 years ago.

 

Key words from the post you quoted - “going straight.” No problem with that.

 

I read as avoid using 4WD on dry pavement... especially if you plan on making any turns. I didn't see anything where engaging 4WD on dry pavement was recommended.