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How do the Auto-Hubs know you slected 4x4 ?


DoctorBill
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I never Four Wheeled before living in the Snow Area of Eastern Washington, so I essentually

know squat about Four Wheel Drive - except for the small amount I've picked up owning a

Suburban, 2 Jeeps and now this '95 Pathfinder.

 

How is it that the Auto-Hubs in my '95 4x4 V6-XE know to make connection

when I pull the 4x4 lever back ?

 

Are the Front Auto-Hubs autonomous - not connected to anything else for a go/no-go signal ?

 

My old '95 Jeep Cherokee had a Vacuum system that locked the front axle into 4x4.

 

Does the Pathfinder 4x4 lever make the Transfer Case lock into 4x4 ?

Then how / why do the Hubs make the connection ?

 

I am somewhat cornfuze-ed in that in some 4x4's, you can leave the front axle locked in

(always rotating) and then lock in the hubs to get Four Wheel Drive.

 

I don't follow how my '95 works.

 

If the Selector Lever engages the Transfer Case to put power up front, then why have Auto-Hubs at all ?

Why not have the front axle always connected to the wheels and the selection occur at the Transfer Case ?

 

Why Both ?! Just to save the energy rotating the front axle ?

 

I don't understand why there would be both a selection at the Transfer Case AND Hubs that need to connect ALSO....

 

Maybe I am just being slow witted today.

 

DoctorBill

Edited by DoctorBill
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Why both? well, allot of vehicles don't have both. Take the R50 for example, its hubs are pemenantly locked and the selection is only done at the lever. So everywhere they go; the front wheels turn the cv wich turns the differential which turns the driveshaft wich turns the un-coupled gear inside the the t-case. If you add it up thats about ~50lbs or more of rotating weight that isn't being used for any purpose. That takes energy wich reduces MPGs and shortens the life of bearings and universals (that normally outlive the vehcile anyway). So when an R50 owner goes to manual hubs and shed all that rotating mass when they are on the steet they gain 1~2 MPGS from it.

 

 

HOW do auto hubs engage? They actually don't engage when you pull the lever but that is the first step. Once the lever is pulled the driveline is engaged(FWD gear>driveshaft>diff>CV joint) once the CV joint turns inside the hub it rotates a clutch that slides into a locked position. This can happen in foward and reverse but only if the CV is beeing driven, in other words the wheel spinning arround a motionless CV will not engage the hub.

 

How do they disengage? since the cv is nolonger being driven all it takes is rotating the wheel in the opposite direction it was going and the spring loaded cluch slides back into a free position.

 

If your feeling adventureous you can take the hub apart to clean it and grease it. Seeing the internals may give you a better Idea of how this works.

Edited by MY1PATH
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Wireless radio signal from inside the transfer case to the hubs?

 

Actualy the mechanism in the hubs is such that when torque is applied through the driveshafts it forces the brake plates inside to lock together, engaging the hub. I don't quite understand EXACTLY how it works, but that's the idea.

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Why both? well, allot of vehicles don't have both. Take the R50 for example, its hubs are pemenantly locked and the selection is only done at the lever. So everywhere they go; the front wheels turn the cv wich turns the differential which turns the driveshaft wich turns the un-coupled gear inside the the t-case. If you add it up thats about ~50lbs or more of rotating weight that isn't being used for any purpose. That takes energy wich reduces MPGs and shortens the life of bearings and universals (that normally outlive the vehcile anyway). So when an R50 owner goes to manual hubs and shed all that rotating mass when they are on the steet they gain 1~2 MPGS from it.

 

Exactly. I put a set of $90 Mile Marker manual hubs on the wife's R50 and instantly got +2mpg so it gets over 20 mpg running at 70-80mph.

 

B

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Wireless radio signal from inside the transfer case to the hubs?

 

Actualy the mechanism in the hubs is such that when torque is applied through the driveshafts it forces the brake plates inside to lock together, engaging the hub. I don't quite understand EXACTLY how it works, but that's the idea.

Sometimes, especially if your truck is higher mileage the brakes can be worn and the hubs will not lock. Though it won't grind as they just slip.

 

If you jack up your truck up so all 4 wheels are off the ground you can start the truck, put it in 4wd and then see if your hubs are engaging.

 

What I do to make sure the hubs lock in is, put it in 4hi, then roll forward a few feet, then go and do what I'm gonna do.

 

The grinding sound is usually the cv's spinning faster than the wheel while the hub is trying to lock.

Edited by adamzan
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Are these the MileMarker's that I'd buy for my '95 V6-XE.....

 

http://4wheelonline.com/MileMarkerNissanHubs.59251

MILEM-435.....Nissan ‘90-’96 (6 bolt 28-spline), Supreme Chrome (435)

for $114.26 with free shipping ?

 

What is this ?

"If OEM automatic hubs, a conversion kit is required to convert manual hubs."

Would I need that 'Conversion Kit' ?

 

Stupid Question ?......that price is for the PAIR of L&R hubs...not each side separately ?

 

Is there anywhere else that has these same hubs for a cheaper price ?

 

If I do this, I just lock 'em in and switch from 2x to 4x at the lever.

 

Should I buy these and install them - or stick with the Auto Hubs I have now ?

Will the opinions come out 50:50 ?

 

DoctorBill

Edited by DoctorBill
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Sometimes, especially if your truck is higher mileage the brakes can be worn and the hubs will not lock. Though it won't grind as they just slip.

 

The FSM has a minimum thickness for the two brakes stacked, 15.4 mm I think. But when I stacked mine they didn't exactly nest together cleanly. The stack was "wobbly" so it was hard to measure. I think if I lined if up so that the two brakes were "parallel" I got more than the minimum, so should be good...

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its all preference,

With the manuals I leave em unlocked most the time to save gas.

If there is snow out or I am at a trail head I lock them and leave em that way untill the snow is gone or the trail run is over. Once locked going 4x4 is a lever only action.

 

some people would rather not "get out and lock/ unlock each time" (not done if you just leave em locked) and others just don't want to bend over and unlock them when they are concered about saving MPG.

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Are these the MileMarker's that I'd buy for my '95 V6-XE.....

 

http://4wheelonline.com/MileMarkerNissanHubs.59251

MILEM-435.....Nissan ‘90-’96 (6 bolt 28-spline), Supreme Chrome (435)

for $114.26 with free shipping ?

 

What is this ?

"If OEM automatic hubs, a conversion kit is required to convert manual hubs."

Would I need that 'Conversion Kit' ?

 

Stupid Question ?......that price is for the PAIR of L&R hubs...not each side separately ?

 

Is there anywhere else that has these same hubs for a cheaper price ?

 

If I do this, I just lock 'em in and switch from 2x to 4x at the lever.

 

Should I buy these and install them - or stick with the Auto Hubs I have now ?

Will the opinions come out 50:50 ?

 

DoctorBill

Yes those are the correct hubs and it is a set of two.

 

I don't know where to get them cheaper but that seems like an ok price to me. You might try www.4x4parts.com.

 

Yes when you lock them you just use the lever inside the truck. Its really a personal preference and most people who off road the truck usually prefer manuals. If the auto hubs are working properly and you just use it in the snow you should be ok.

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Hells Bells...I just ordered them a while ago !

 

I don't have the patience to wait for folks to give me their opinion.

 

Now I just hope none of the 12 bolts breaks off in the axle side of the Hub.

 

I took off my wife's Geo Tracker's Manual Hubs and cleaned and lubed them several

years ago.

A couple of the Bolts didn't want to start unscrewing.

Scared the Hell out of me....removing broken off bolts inside something is my

idea of a nightmare come to life.

 

The Tracker is now deceased - someone drove across the 55 mph highway right

in front of my wife. Crumpled the front end (totaled) but she is OK except for

a screwed up shoulder and neck. Other person had the minimum legal insurance !

 

Anyway, I finally got my 3/8 inch hex driver set out of mothballs and put it on my

air hammer for taking off wheels.

 

THAT got them moving ! Nothing like an air powered Rotating Hammer to

take off recalcitrant nuts and bolts....after some "KROIL" has soaked into

the threads for a day.

 

KROIL is one amazing product ! Hard to find, but a miracle in itself.

Some Gun Reloading shops that I frequent carry the stuff.

 

Should I spritz some Spray Oil into the new Hubs before I install them ?

Can I trust the Manufacturer to have lubed them properly ?

 

You know....the old "Trust me! I know what I'm doing !" thing. Ha....!

 

DoctorBill

Edited by DoctorBill
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Questions about replacing the Auto Hubs with Mile Marker Manual Hubs (on order)....

 

Do those hubs come with six new bolts for each side ?

 

Am thinking of having a mechanic do the change over.

Too miserably cold and wet to do it myself - getting too old, also.

 

How long should it take ($75 per hour) ?

 

Has anyone ever had the bolts stick and break off ?

 

Anything the Mechanic should watch out for ?

 

DoctorBill

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Do I have to use the old bolts or do these Mile Marker hubs come with new bolts ?

 

I suppose I should use the anti-seize compound on the threads, also.

 

DoctorBill

Edited by DoctorBill
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Whan I installed MMs I reused my stock bolts and stock snap ring on the CV. I wouldn't bother paying someone, it takes like 10min per hub to swap. If you were local I'd swap em for you for a beer per hub :laugh: !

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Has anyone looking at this ever ordered anything from

 

http://4wheelonline.com/ ?

 

They say don't even ask about a tracking number until 4-5 days after ordering !

 

Most places ship the next day or the day after....

 

Are these people really slow to ship ?

 

DoctorBill

 

PS - Edited in later.

E-Mailed Customer Support today (10th - 5 days later) and asked about my order.

Got this back:

"I called the warehouse and the manager told me the part is a special order. So the current due date is 12-28-10.

Thank you,

Jed V.

4 Wheel Online Customer Service

www.4wheelonline.com

1-813-769-2451

1-813-769-2467- Fax"

Funny thing - my VISA was debited $114.26 two days ago.....

I had to ask before they let me know it was not in stock.

Their web site did not say it was a special order item, either.

"Supposed" to be in 2.5 weeks from now then add shipping time.

You be the judge about this place.....

Edited by DoctorBill
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I ordered the Mile Maker hubs for my '95 Nissan from 4wheelonline.com on 12-5.

 

http://www.nissanpathfinders.net/forum/index.php?showtopic=28766&view=findpost&p=548098

 

You wouldn't know that I had done anything except that they debited my VISA

card on 12-8 for $114.26 ! They pay the shipping.

 

I finally asked them what was going on....they said the item won't get in

until 28 December....never heard from them again.

 

Supposedly a special order item - which was not elucidated on the order page...

 

Is this normal behavior for 4wheelonline.com ?

 

I am not a happy camper, as it were.

 

I am surprised that no one has commented on this mail order outfit....

guess very few order from them.

Wish I had known better.

DoctorBill

Edited by DoctorBill
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We bought the wife's at 4wheelparts.com. Then they called and said they were back ordered and it would be another 6 weeks. Ok, we waited and got them about 2 months later, still at the sale price. We didn't need them immediately, but yes, that is how many places operate. You should be able to cancel the order and get a refund to order elsewhere, but in our case NO ONE IN THE US HAD THE PARTS IN STOCK. :shrug:

 

B

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  • 2 weeks later...

I received the Mile Marker Hubs from 4WhellOnline.com today via UPS.

 

They look good. 90 day warranty. No invoice with the package.

 

4WheelOnline sent them when they said they would.

 

Had they told me these were a special order item right up front, I would

not have anything to criticize them for.

 

OK - Apparently I have to remove the Drive Flange and Gasket before installing

these babies.

 

d8a2383cd8.jpg

 

I assume I have to jack the vehicle up to do this....take the wheel off.

 

Is there anything I should watch out for - be aware of when doing this

replacement ?

 

DoctorBill

Edited by DoctorBill
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