4wd for dummies...

[LMcD]

Hi all,
I have been reading some threads on 4wd and what to do and what not to do. I have had it for a few months now and have not put the machine in 4wd yet.

This thread was pretty helpful
( http://www.delica.ca/forum/turning-on-p ... 91-15.html )

But. Could someone dumb the basic do's and dont's down for me, and hopefully answer a few questions with my 93 l300 super exceed.
What is this locking hub stuff? Manual or Auto...how do I know what I have?
Once stopped, can I just put it in 4wd and drive away?
On snow covered roads can I drive in 4wd? Can I drive at say 50kph for an hour while commuting to/from work on snow covered roads?
Once in 4wd can I reverse? or this there something funny that happens with the hubs?

Much Thanks,
LMcD

[Big-Bird]

Welcome to the forum.

Locking Hubs: Part of the front drive assembly that sits in the middle of the front wheels. Some Delicas have manual hubs and some have auto hubs. Manual hubs have a dial that must be turned by hand to physically engage the lock ring gear which in turn engages the CV axle.


Auto Hubs will engage when the transfer case is placed in a 4WD mode which causes the front driveshaft to turn which causes the front CV axles to turn and that engages the auto hubs....automatically. Auto hubs use a cam design that is turned by the CV axle which engages the lock ring gear.


Both have their advantages/disadvantages.

(+)Manual hubs tend to be stronger and ensure a positive lock. (-)Have to get in and out of the vehicle to use them.
(+) Auto hubs can engage into 4wd even while the vehicle is moving (at slower speeds). (-) Weak/Poorly maintained hubs can disengage unexpectedly when backing up while in 4WD.

4WD high can be used at highway speed but the rule of thumb is only use it if road conditions warrant it. And if the roads are so bad you need 4wd perhaps you should not hit 90+ kph!

4wd low is a crawler gear, Engine RPMs run higher but forward speed is slower. Used on difficult terrain, while pulling heavy loads or going up steep inclines. Good for keeping engine RPM's up so the engine doesn't bog down and stall. Also increases torque to the wheels without revving the snot out your motor.

Taking hard turns while in 4wd (hi or low) puts stress on the entire drive train. Its really risky when the driving surface is dry pavement because the stress can potentially break CV axles, auto/manual hubs and in extreme cases differentials....all get very pricey to repair. This is far less of an issue in soft dirt, icy roads, gravel, and even snow because these surfaces allow for wheel slippage which reduces the stress.


Regardless if your Delica has auto or manual hubs its a good habit to back up 3-6 feet after you disengage 4WD to ensure the hubs are disengaged. A partially engaged hub can cause a loss of control situation or severely damage the 4WD system if it were to engage on its own. Lots of cruching sounds usually occur.

Rule of thumb: you don't need 4wd to hit the drive through the Timmy's or McD's!

Happy wheelin'

[konadog]

Some L-300's have permanently locked hubs too. They look just like L-400 hubs. Pretty rare, but I got one like that and have since upgraded to manuals. I have seen a few other 300's like that.
If you have manual hubs you have the option of unlocking them and using the low range gears on pavement. Convenient for me with my utility trailer and a steep, tricky driveway.
Also, it serves no purpose to reverse after disengaging manual or perma-locked hubs. With manuals it's all in the "manual" switch.

[Big-Bird]

Some L-300's have permanently locked hubs too. They look just like L-400 hubs. Pretty rare, but I got one like that and have since upgraded to manuals. I have seen a few other 300's like that.
If you have manual hubs you have the option of unlocking them and using the low range gears on pavement. Convenient for me with my utility trailer and a steep, tricky driveway.
Also, it serves no purpose to reverse after disengaging manual or perma-locked hubs. With manuals it's all in the "manual" switch.

Permanent hubs are usually referred to as drive flanges and the only way to disable them is to unbolt them, rare...agreed and yes many people switch to manual hubs to try and reduce wear and gain better fuel economy, improve 4WD options.

As for "serves no purpose to back up with auto or manual hubs" you are very wrong. Most times the engagement gear will release as long as there is no pressure/load on them. Backing up after disengaging 4WD (manual hubs unlocked) is a good practice because it ensures the engagement gear is fully released. I have been offroading with all kinds of trucks, SUVs and such for over 15 years and all it takes is one time to ruin your day. An auto hub in my Xterra did grenade and its because I didn't back up 1 time and ensure a full release. Perhaps you have been lucky with your Deli but the cost to fix my issue was more painful than backing up 3 feet just to be sure.

[konadog]

Switching from perma-locked flanges won't help fuel economy. I was hoping it would when I upgraded, but was told by CCA Glen to not expect any measurable improvement in fuel economy. He was right. He also told me I don't need to reverse after disengaging manual hubs. Same thing my last mechanic told me. Have never done it in 20 years of driving manual hub equipped 4x4's and have never had a problem. I reckon nobody gave a thought to reversing after disengaging 4x4 until the introduction of auto-hubs and the need to use the reverse motion to unlock them.

[LMcD]

Thanks Folks.

After I wrote my post, I went out to look at my machine, and it says "Auto Free Hub" on it....
I should have looked before writing...but thanks for the info and keeping it simple.

We had a good storm here in NS yesterday and I took her for a few drives in 4WD.... she was pretty awesome in the snow and climbing the snowy streets with hills. Put a good smile on my face.

LMcD

[TRUTHautomotive]

So just to clarify, because most of my experience is with AWD systems.
The delica's 4WD system is resilient enough to use 4H on highway and city (gentle corners) in snowy/icy conditions? (Alberta winters)

[konadog]

So just to clarify, because most of my experience is with AWD systems.
The delica's 4WD system is resilient enough to use 4H on highway and city (gentle corners) in snowy/icy conditions? (Alberta winters)

Yes - as long as the surface is slippery you can be in 4x4. Exposed pavement, wet or dry, is BAD - snow or ice covered pavement is OK. You can leave the hubs locked and pop in and out of 4h as conditions require. You can change while moving as long as it's in a straight line and you're not going too fast. They say up to 80 clicks, but I feel that's too fast. Switch gently...

(edited for spelling / clarity)

[vstrom]

So I have flanges on mine, and I've often thought of going back to manual hubs. With manual hubs can you leave them locked indefinitely? No harm done? Only reason why I'd want manual is for the ability to use 2LO once in awhile. Otherwise I'm happy with the flanges.

[konadog]

So I have flanges on mine, and I've often thought of going back to manual hubs. With manual hubs can you leave them locked indefinitely? No harm done? Only reason why I'd want manual is for the ability to use 2LO once in awhile. Otherwise I'm happy with the flanges.

My bus came with flanges too. Basically they are permanently locked hubs. I changed over to manuals so that I could use 2LO as well. Happy with the change. You can leave manuals locked no problem, just don't go into 4x4 unless you're on a slippery surface. I spent 1/2 the winter with the hubs left locked.

[vstrom]

Right on, thanks Kdog.. thats what I thought.