which wheels drive in forward mode? (Full Version)

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which wheels drive in forward mode?

  

skeeet -> which wheels drive in forward mode? (10/19/2006 2:38:53 AM)

Does anyone know which wheels are the drive wheels when going forward ( locking diff. off). I was wondering this because in addition to my spare 315x75x16 tire I also carry an extra factory 285x75x16 and did not want to stress out the transfer case if I had to use the 285 with the 315's. If I used it on the non drive wheel this would not happen. I think the front left and rear right are the drive wheels in forward mode?

  
jettech737 -> RE: which wheels drive in forward mode? (10/19/2006 9:18:51 AM)

All of the wheels are drive wheels even with the locking diff turned off.
In normal conditions both wheels on an axel will receive equal
power, but when one wheel loses traction the other wheel will stop spining.
When you engage the locking diff the axel will send power to the oposite wheel.
So to answer your question it does not matter which side you use it on. But as far as to
damaging your transfer case I don't know about that.

fisherman119 -> RE: which wheels drive in forward mode? (10/19/2006 11:12:36 AM)

frount driver' rear passanger????????

Fireman -> RE: which wheels drive in forward mode? (10/19/2006 11:21:40 AM)

The "in a nutshell answer" is all of them. Even though it is full time 4wd, it's not the same as being in high lock .. but the transfer case does act like a differential and allow for traction variances to be applied to various wheels in the case of slippage. High lock will send dedicated power to all wheels, but transfer of power still applies via the front and rear diffs, provided the rear locker is not activated. If the rear locker is activated, then there is no "transfer" in the rear, and both wheels will turn equal with throttle input. In that case there will still be variances up front, based on traction, but those variances only apply to the front wheels, and their traction at the time. These variances would not occure if the front axle also had a locker, .. in that case they too would turn all the time when engaged.

Ditch your smaller tire, you don't need the added weight, and it won't do you any good. You can cause damage by running it. When in high 4wd (street mode) if slippage causes the t-case to send power to the wheel that has the smaller tire, then you can put stress in the form of binding, on the t-case. The same way you should never run different axle ratio gears front to rear, you shouldn't run larger or smaller tires front to rear, or different sized tires on a locker equipped axle. If the smaller tire is the "driver" at that time, then you t-case is trying to turn on axle at one speed, and the other at another speed. Chances are it will just bind and click and pop.. without breaking anything.. but it's best to just avoid it all together. All 4wd vehicles need to run equal sized tires, especially full time 4wd.

Dennis -> RE: which wheels drive in forward mode? (10/19/2006 11:37:37 AM)

Question:

I know the 4Wheel Hi lock distributes the power 50/50 as apposed to 60/40 without the lock on...Also it will only engage to the Hi-lock below 45 mph.


My question is; If you are driving in Ice and heavy snow conditions would it be best to have the 4Wheel High lock on?

shortbus -> RE: which wheels drive in forward mode? (10/19/2006 11:45:56 AM)

for the snow and ice situation, i would say yes, 4 hi lock is an advantage, albeit a small one. the weight of the engine will help give the front wheels more pressure and hopefully help with steering. although if you're on ice, it's a toss up as to what will help. just don't go into 4 lo lock and back up, unless you're only going straight.

Fireman -> RE: which wheels drive in forward mode? (10/19/2006 11:49:32 AM)


quote:

ORIGINAL: Dennis

Question:

I know the 4Wheel Hi lock distributes the power 50/50 as apposed to 60/40 without the lock on...Also it will only engage to the Hi-lock below 45 mph.


My question is; If you are driving in Ice and heavy snow conditions would it be best to have the 4Wheel High lock on?


I'd say yes to using the high lock as long as the conditions are pretty icey, and with the heavy snow. It's probably safer too since the system won't "hunt" for slippage/traction as much. This way you have the dedicated power and the system will be less likely to slip to start with. I would return to normal high if the road is, or gets, drier though. It may be best, but as you know, I'm sure that normal high would be ok too. I guess it boils down to: is the added safety worth the extra gas. I know in my case it would be.

Being in south Texas, I rarely have to deal with those conditions. On my old full time 4wd truck I ran hi-lock on the road, twice, with ice and snow with no troubles.

Dennis -> RE: which wheels drive in forward mode? (10/19/2006 11:55:40 AM)

Thanks..Shorty & Fireman

I'm looking at the same sorta light conditions for winter here too in OKC..But once in a blue moon it dumps a load on us for a few days..

Linus Gump -> RE: which wheels drive in forward mode? (10/19/2006 1:32:12 PM)

One thing I dicovered last winter is to disengage the traction control system when you are on snow and ice on the street. It tries to brake the tire that slips. This brake action doesn't seem to use ABS so the tire locks of a second which causes the vehicle to slide around a bit. It can get kind of scarey when you expext the vehicle to go one way, but the TCS makes it go a different way.

skeeet -> RE: which wheels drive in forward mode? (10/20/2006 12:42:55 AM)

Jettech737 - I do not think that all wheels are drive wheels unless you have a posi diff in front and back. I have been on ice several times and in several of my 4 wheel drives. Since the vehicle was only spinning the wheels and not moving forward I Got out and saw only one wheel in the front and one wheel in the rear moving. When I put it in reverse it was the opposite wheels that were spinning. I just forgot if it was the front left and right rear that move in DRIVE.

Fireman -> RE: which wheels drive in forward mode? (10/20/2006 12:51:50 AM)


quote:

ORIGINAL: skeeet

Jettech737 - I do not think that all wheels are drive wheels unless you have a posi diff in front and back. I have been on ice several times and in several of my 4 wheel drives. Since the vehicle was only spinning the wheels and not moving forward I Got out and saw only one wheel in the front and one wheel in the rear moving. When I put it in reverse it was the opposite wheels that were spinning. I just forgot if it was the front left and right rear that move in DRIVE.


Was that other 4wd a fulltime 4wd, with traction control?

skeeet -> RE: which wheels drive in forward mode? (10/22/2006 1:02:31 AM)

The 1979 Grand Cherokee was a full time four wheel drive, the FJ40 was manual front locking hubs, CJ7 and Pathfinder were not full time. I just do not see how a non posi diff vehicle can have both wheels have power in one direction. Take any full time "four wheel drive" and get it in dirt, put it in drive and floor it and you wll see only one rear wheel spin and dig in on each axle. Full time units will only transfer power from the center diff back and forth to the front and rear diffs unless you lock it and then front and rear diffs get equal power. This has nothing to do with what is going on in the front and rear differential. If it is not a locker or a posi unit on that axle there will be only ONE wheel getting any power and the opposite wheel will get power when in reverse. If this was not true then why would they even need a posi option if the axle automatically powered both wheels?

Fireman -> RE: which wheels drive in forward mode? (10/22/2006 1:50:32 AM)


quote:

ORIGINAL: skeeet

The 1979 Grand Cherokee was a full time four wheel drive, the FJ40 was manual front locking hubs, CJ7 and Pathfinder were not full time. I just do not see how a non posi diff vehicle can have both wheels have power in one direction. Take any full time "four wheel drive" and get it in dirt, put it in drive and floor it and you wll see only one rear wheel spin and dig in on each axle. Full time units will only transfer power from the center diff back and forth to the front and rear diffs unless you lock it and then front and rear diffs get equal power. This has nothing to do with what is going on in the front and rear differential. If it is not a locker or a posi unit on that axle there will be only ONE wheel getting any power and the opposite wheel will get power when in reverse. If this was not true then why would they even need a posi option if the axle automatically powered both wheels?


Sorry, but that's not all totally true. My old 77 K10 was fulltime, and would almost always spin all 4 tires with open diffs. On several occasions I've pulled stuck trucks out, and looked at 4 "black marks" where my wheels were spinning. I think it's when you jack the vehicle up off the ground, and no wheels are touching that you get the "one wheel up front, and one rear wheel" turning effect. I still believe that a certain amount of torque is applied to both wheels on a given axle.

So, with what you've said, and what I know.. if you have the adventure package, then that leaves you with one place to run your smaller spare. You can't run it in back if you have the locker (at least not when it's on), so run it up front. However, it's usually advised to put smaller tires on non-steering axles.. so if you have a rear locker that pretty much leaves you no great options. Now, if you don't have the adventure package.. you can run it out back... or you can elect to leave the locker off, which sort of sucks depending on your situation... seeing as it's a great advantage to have.

I really don't see the point of running a smaller tire when you already have a correct size spare.. when all you would really need to do is carry a small 12v compressor, and a tire plug kit (which take up a lot less space, and saves gas etc). Plug and fill the flat, and save the good spare for the trip home. As long as I've been wheeling, I wouldn't waste the effort to carry around something that wouldn't serve my needs 100%. I don't see your smaller spare doing that.. since you have to try and figure out where it's ok to run it.

So in the end, I just feel that it's a moot point, when theres much better options out there. I can understand carrying two spares for extremely remote locations.. like the Australian outback, or something along those lines.. but toting two around for a much shorter wheeling trip.. or everyday, is just sort of silly to me. There are better options.. and they don't include potential damage to the system. I'd sell that spare to someone who could use it, and put my money towards better provisions. But, that's just me.

shortbus -> RE: which wheels drive in forward mode? (10/22/2006 2:38:02 AM)

i assume the H2 has the same type of drive system as the H3. i had all 4 tires barking on the slickrock in moab, and only the rear has a locker. maybe the bus really is retarded, but it had power to both front wheels at the same time . . . and i only had one spare, for whatever that's worth . . . .

HummerMike -> RE: which wheels drive in forward mode? (10/22/2006 10:56:16 AM)

I'd like to comment on the snow driving. Last year I had the joy of driving in a very heavy snow storm in Chicago. It was the night a Southwest Plane skidded off the runway at Midway Airport crushing a car and killing one person.

Anyway, I played around with the 4 wheel options to see what combo I felt worked best. Now I was in about 6-8" of snow on the road and no plows were able to keep the roads clear at this particular time. I found that running in 4 High Lock with the Stabili-Trac system turned off worked the best. Running in 4 High lock gave me the best traction and control in turning. The stabili-trac system kept trying to take over when it felt any kind of slippage whatsover so I found myself "fighting" the truck more than actually trying to drive. Now, I know that the system was just doing it's job but I prefer to use my hazardous driving skills and control the vehicle myself. That's just me.

My reccomendation to anyone that is going into the snow season is to go out to a large parking lot or somewhere where you wont crash into someone/something as soon as you get a decent snowfall or some ice and play around with the different options. It's better to be prepared and know how your vehicle is going to react when you get out into a real situation.

Mike

  

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