Help me understand the 4HI 4Lo Settings on H3

[H3Lady]

Can someone kinda of let me know how to use the buttons on the dash for 4hi 4lo and when to use them and in what condtions. We have sometime heavy snow here too.

PS...I turn off stabiltrack and I feel the H3 rides better, but plan to leave it on in wet weather.

[HummerNewbie]

If you need to be in 4HI Lock, you probably shouldn't be driving at highway speeds anyway

[wannabeH3]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">

I'll bet you lunch it's 5.... </div></BLOCKQUOTE>

your on im gonna make a movie with my digicam! haha

[Hummer H3 SUV]

You might want to read the manual that comes with our Hummers.

[Hummer Guy]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jkH1+H2=H3:
Should and does the 4 ^ always stay lit.? Do you need to be in Dive 2 or 3 to have the Rear Differental work?? </div></BLOCKQUOTE>
You probably meant locking rear differential working? In that case, the locking rear will only work when in 4 low lock, but you do not have to be in a lower gear -- but you'll probably want to be!

[Georgemarc]

Just to the right of the 4LO Lock

[hyperion78]

how close are the H3 diffs and all to the 03 bravada AWD system. My parents have one and they're having issues with it feeling like it's slipping when you're hard on the gas. I test drove an H3 today and it felt like it was sort of doing that too. Couldn't tell if it was that or the bumps in the road.

[Steve R]

Anyone care to touch on the subject at hand?

The only difference between 4hi OR 4hi-locked is that the transfer case locks; this is essentially the center-differential. You only want this "locked" situation when there can be slippage on the ground (mud, snow, sand...loose conditions).

You do not want to use this setting when on pavement. We've had a couple instances where some H2 owners forgot to switch out of 4hi-locked and drove on pavement long distances...only to fry their t-cases!

Enough said...but if you want more:

When a vehicle makes a turn, the outside wheel will turn more rotations then the inside wheel...this is the reason for a differential, it essentiall absorbs the difference in the axle. Much in the same way, when a vehicle turns the front axle will cover a different distance then the rear axle...and so the transfer case has a slippage device to account for this. This slippage device can make things sloppy offroad, and so we lucky Hummer owners can "lock" this center differential.....and so the transfer case is "locked"

Enough said....want more?

Try this: find a parking lot where there is dirt. do some tight circles and you can feel the vehicle easily turning. (roll down your windows to listen). NOW, go into 4hi-locked and make those same circles: you may sense/feel some hesitation and even hear the ground breaking as the slippage is no longer afforded.

Good quesiton!

[BUKHUM]

thanks everyone for the lesson when to use 4HI, 4HI Locked, 4LO...good review

SFOX...danks fo duh engis lesson...

[Steve R]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by tacocat:
Does the center diff truly lock or is it one of those visco clutch deals?

Personally, I would like to see a T-case offer 2wd, 4Hi full-time, 4Hi part-time, and 4Lo with a true locking center diff. </div></BLOCKQUOTE>

I too would like to have seen a 2wd option on the t-case, not sure why they don't have it, probably cheaper and easier to make it the way it is. They figured a full-time 4wd is fine.

As for the locking t-case, I'm not sure whether it's a locking or viscous deal. Most the high-tech mechanical guys will tell you that only the axles have differentials, etc....our transfer case doesn't exactly have a differential, but something so similiar that it's fine to think of it as a locker. In normal operation I think we split power 70% to rear and 30% to front, then it become 50/50 when locked.

Here is one thing I can tell...from experience: if you jack 3 wheels up in the air and try to move forward with just one wheel on the ground...you won't go anywhere in 4-hi UNlocked. Once you switch to 4hi-locked, you'll move on that one tire on the ground.

[tacocat]

Steve hit that one on the head. A typical full-time 4x4 has three differentials, front, center, and rear. As far as using part-time 4wd, part-time 4Hi is typically employed when the ground allows slippage and you want to carry some speed. 4Hi will come in handy during mud bogging, dune running, or playing in the snow.

If you have the 4.03:1 T-case, 4Hi will probably be really handy.

Does the center diff truly lock or is it one of those visco clutch deals? Personally, I would like to see a T-case offer 2wd, 4Hi full-time, 4Hi part-time, and 4Lo with a true locking center diff.

[wannabeH3]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Steve R:
Anyone care to touch on the subject at hand?

The only difference between 4hi OR 4hi-locked is that the transfer case locks; this is essentially the center-differential. You only want this "locked" situation when there can be slippage on the ground (mud, snow, sand...loose conditions).

</div></BLOCKQUOTE>

i dont think thats correct, i thought you had 4 hi 4 hi locked (REAR DIFF LOCKED) 4LO locked with rear diff locked, and then you have the center diff locking button only usable with 4 lo lock. am i wrong? right?

[Hummer Guy]

4HI -- everyday driving
4HI Lock -- Slippery mud, snow, ice, sand
4LO Lock -- Rock crawling, step climing, DEEP snow.

Some places will say to use 4hi lock in the rain -- I've never been a fan of that recomendation unless it's some kind of hurricane...

[H3Lady]

yup thanks

[Steve R]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by wannabeH3:
am i wrong? right? </div></BLOCKQUOTE>

Right, you're wrong.

The rear locker is actuated seperately via a button, it's operational only in 4-lo. It locks the rear differential.

The transfer case, which distributes power to the front axle and rear axle, has it's own differential of sorts. Unlocked (aka full-time 4wd) it distributes power 70% to rear, 30% to front and allows slippage. Locked (aka part-time 4wd) is just turns front & rear axle irregardless of either axle having traction or not.

It's really quite simple once you get beyond the confusing issues.

One thing I will say, it's important to know and fully understand these features and how they work when offroading. More valuable then most realize.

[H3OH]

Last I checked, I had a little black book sitting in my glove compartment...

[wannabeH3]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Hummer Guy:
In order to turn it off you have to hold it down for 5 seconds and a little light will come on the dash...if you have an adventure package, its right next to the locking rear diff button </div></BLOCKQUOTE>

its 10 seconds!

[Hummer Guy]

In order to turn it off you have to hold it down for 5 seconds and a little light will come on the dash...if you have an adventure package, its right next to the locking rear diff button

[jkH1+H2=H3]

Whats up Sorry my english is a little off today.....U must be a Babe magnet.

[Hummer Guy]

who are you talking to H3SUV?