I wonder does my car have any kind of locking differentials? rear diff lock button is missing... what 4wd means? how it behaves? please..... 4runner 1998 limited.

The 4wd button acts like AWD. Safe to drive in any conditions. But you should have a center diff lock button. I know my '01 does, but maybe '98 is different, idk.

'98 is different. It is part-time 4wd only.

Pushing the button on the side of the lever, puts the truck in part-time 4wd, which means it should be used in slippery conditions. There is no differential in the '98 transfer case.

If he has the rear diff locker, there will be a button that says "RR diff lock" to the side of the steering column on the dash.

Like this:

no it doesn't have any locking buttons.. do you know what is L4? thank you for response

oh yes, I saw this picture earlier and couldn't find this button on my car. what part time 4wd means?

So, when the button is not pushed, the tcase is only putting power to the rear driveshaft. That's rear wheel drive. When you push that button, that tells the tcase to power the front and rear driveshafts equally. This is what's called "part time 4wd" - you don't have full time 4wd. There is no center diff on the transfer case, so you want to try and limit your 4wd use to surfaces where it's relatively easy for the tires to break traction - gravel, dirt, snow, ice, etc. It's not the end of the world if you use 4wd on dry pavement, but be aware that it adds stresses to your drivetrain and has been known to break stuff.

When the shift lever is in the "H" position and the button is pushed, you're in what's called "four-high", which means there's no additional gear reduction happening in the transfer case. When the 4wd selector is in "l4", that's called "four-low", and the transfer case has engaged a set of gearing (2.26 to 1, I think? Somewhere thereabouts anyway.) that drops your final gear ratio, meaning you get much more torque available but your RPMs will be much higher for a given wheel speed. Four-low is for climbing very steep hills or very slowly crawling over obstacles like rocks or crossing a deep rut. It multiplies your torque, so don't use it if you're in a very low traction situation (bad mud/slippery ice/etc) or plan on doing more than 20mph.

You don't have a locking rear differential, or a center diff that would give you multimode, or full-time 4wd.

thank you very much!

is it same when you lock center diff on full time 4wd?

If I understand what you're asking, yes. Some vehicles have a "center differential" (similiar to an axle differential, but part of the transfer case) that lets the front and rear driveshafts turn at different speeds, this is called full-time 4wd. Some trucks with full time 4wd also have a way to "lock" that center diff. When the center diff is locked, the system behaves exactly like a part time 4wd system (like yours), which is useful in low traction situations where one or more tires are likely to spin.

In Toyota trucks, that full-time 4wd with the center diff lock is called "multimode" - not every truck has it. Other manufacturers have different systems with different names.

Now its all clear to me. Big thanks to you Kevin!

Hi, I just had a question regarding the combination of manual hubs with a locking differential. Solo Motorsports has an adaption in there long travel kit to have dana 44 manual locking hubs. I figured I could do those and then get a spool piece for the front instead of a locker. Street would just have hubs unlocked, and off road they would be locked. There doesn't seem to be much information on this topic, can anyone explain to me why this wouldn't work?

You lock manual hubs whenever your sending power to the front wheels (so in AWD or 4wd). Not locking them in 4wd sends power to the front diff, but it wont get to the wheels. So being in 4wd/awd with the hubs unlocked is as good as 2wd.

You keep them unlocked when not sending power to the front wheels to save wear and gain MPG. With the manual hubs unlocked, the front differential is not being turned.

Just treat your manual hubs same as your 4wd. When ones locked, the other needs to be locked

Would it work purely mechanically speaking? Yes, kinda. Would it work in practice? No, a spool in the front end would effectively kill your turning radius (or ability to turn at all, for that matter) - nor will you ever, ever be able to use 4x4 on pavement without seriously damaging your diff.
You're far from the first to ask spool in front axle? | Pirate 4x4