Do I Really Need the Differential Lock? -help

[02SE]

First I've ever heard of "part time" 4wd. That 4WD button is responsible for sliding the selector fork in the front diff over to engage it. As I remember it (before I did the 5spd swap) the front drive shaft was always engaged. All the wheels were waiting on was that front diff to be engaged to get power.

It may be the first time you've heard the term "part-time" 4wd, but nevertheless that is what it is.

Furthermore, the transfer case in a '96- '98 Limited is not sending power to the front end, until the 4wd button on the transfer case lever is pushed. Or on manual J-shift transfer cases until the lever is moved from 2Hi to 4Hi.

Doing so moves a shift fork in the transfer case, which engages a chain coupling in the transfer case, which in turn sends power through the inverted tooth Morse chain to the front output chain coupling, which is splined and bolted to the front output flange, to which the front driveshaft is bolted. Thus sending power through the front driveshaft to the front differential.

The front driveshaft IS NOT always spinning.

From the factory, we have what is called A.D.D for Automatic Disconnecting Differential. In such a system, the driver's side front CV-axle shaft is always spinning the side gears and spider gears in the front differential when the vehicle is moving. The passenger side CV-axle is spinning up to the A.D.D coupler. When the 4wd button is pushed on the transfer case lever, (or the lever manually shifted for manual systems) the transfer case sends power to the front output, (as I previously described) while the A.D.D coupler simultaneously engages the front right passenger side CV-axle to the front differential. As you described in your quoted post.

Part-time 4wd means there is no differentiation between the front and rear driveshafts. Since there is no differentiation between the front and rear driveshafts, the driveline can bind and even possibly break parts, if the part-time system is used in high traction situations. Hence the recommendation to use it when road conditions allow some wheel slip, to help alleviate binding and potential breakage.

Full-time 4wd traditionally has meant the vehicle has a high and low range transfer case with a differential in it, which allows the front and rear driveshafts to turn at different speeds.

All-wheel drive (AWD) traditionally has meant a vehicle with no low-range, which can send power to the front and rear driveshafts, and allows those driveshafts to turn at different speeds from each other. That ability means it can be used all the time, on any surface without the driveline binding.

That said, AWD is the term usually used on this board, for the Full-time 4wd capability which some years and models of 4Runners have.

 

[PNW yota]

Then get the best of both world, find a good 2000-2002 with a locking center and multi mode 4wd then retro fit an e locker (which isn't that expensive honestly) and Your set.

That way you have true flexibility and still factory components.

Or just buy a 1999 or 2000 with the multi-mode (which allows locking or unlocking center diff operation) and factory locker...

Like a few have already stated, most owners have no idea what the button does, other than make lights on their dash blink (since they push the button when not in 4-Lo because the rig never sees anything but pavement), so it's not likely to be a major selling point that drives price up.

 

[4Running Daily]

I'm with everyone that's saying you should hold out and wait for one to come up that already has the e-locker. I really don't think it's going to add any more to the price. 3 out 4 factory locked 3rd gens I've been involved in buying, had absolutely no clue what the locker even was.



But really, whether you'll need the locker or not depends on the type of wheeling you'll be doing. Since you plan on doing snow wheeling, I'd say it's worth it.



I've been on plenty of trails that I never needed a locker for. Then there's the trails that I wouldn't have made it up without the e-locker. Then there's other trails that you won't make it up unless you're locked front and rear.



You can see in this video that even having a rear locker wasn't enough, I need the front locker:






And in this one, the hill at the end took [MENTION=75445]4Running Daily[/MENTION] 5 tries even with the rear locked, while I walked up it the first try. That part starts at 1:38, and unfortunately the camera died before I went up it:





So lockers can be very useful if you're on hard enough trails. Plus, they help to not mess up the trail so much since you're less likely to sit there, spinning the tires, digging a hole.



That's my two cents.

Just wait until I make it up the water tower line before you


OP, lockers are nice, but you don't NEED one. If you find a clean well maintained open diff 4Runner, buy it. Lockers can always be added if it's a necessity. Buy an open diff 4Runner, put on a Toytec Ultimate Lift kit with Superflex rear coils, and add on some decent rubber and you'll be amazed the places you can go.

 

[Gerdo]

Thanks for the great info. I've been stuck in thick snow before and it's not fun. Those are the situations I was thinking it would be handy.

Thick snow like the vehicle was sitting on it's belly in snow? If you high center a rig in snow, all the chains and all the lockers are not going to allow you to drive off it. This is why a winch is almost a must for someone that could end up like this when alone. The winch will pull you thru it or back off it.

I want to get a rear locker installed on my 2000, but I don't know how much that would cost. I am not capable of doing it myself, so I would have to have someone get the part and do it. Hopefully it wouldn't be more than $600.

I bought a built third member with an ARB air locker and installed it. The shop that I would take a vehicle to get one installed in Denver would be Western Drivetrain.

You want a selectable locker, not an auto locker! An ARB with compressor is going to cost over $1200 in just parts. Personally the air locker is way better than an E-Locker. It locks and unlocks almost instantly. I can try an obstacle open and if I NEED to lock to get thru, hit the switch and it locks without needing to move.

Again, NEED a locker? Nope. And I wheel with a group that wheels hard trails. Most of us don't use our lockers that much.