[moonlight]

If you don't actually need to? My SO said he remembered hearing somewhere that you shouldn't engage the 4 wheel drive unless you were actually slipping and needed it.

I like to engage it if I'm on rough, potholey, dirtroad in case I need it. Is that a bad thing?

thanks!

[MR.CLIFFORD]

as long as your wheels are on a surface that will allow slipping then you won't damage anything. Driving around on pavement in 4wd is stupid. Off road is alright but why would you "need" it?

[knoxville]

Originally Posted by moonlight

If you don't actually need to? My SO said he remembered hearing somewhere that you shouldn't engage the 4 wheel drive unless you were actually slipping and needed it.

I like to engage it if I'm on rough, potholey, dirtroad in case I need it. Is that a bad thing?

thanks!

I know that 4wd lever is very beautiful, and is hard to not touch - but just wait until you need it. potholes....dirtroad....2wd man.

Mr.Clifford is right...wait until the slipping occurs. Have fun and be safe.

[moonlight]

Well, in the case of today, I was on a logging road that climbed a pretty high hill near my house....parts of the road were quite steep and the first time I encountered a steep part, my wheels slipped some. That's why I put it in 4 wheel for the rest of the climb, even though most of it was easily handled by two.

The logging roads are very cool here in the PNW when you're allowed access...they go way up into the mountains, often carved in the hillside with cliff like drop offs on the outside of the road...

[Dacaur]

Putting it in 4wd when you are on a dirt road is fine the only time you shouldn't put in in 4 is on dry pavement, like it says above, as long as the tires can slip, its fine to put it in 4 and wont hurt a thing. I personally put in in 4 any time I think there is a chance of needing it, its better to be in 4 and not need it, then to get stuck in 2 and hope you can get out, when you have lost traction and your wheels are already spinning is NOT the time to put it 4 wheel drive....

[CoriolisSTORM]

just a question related to this guys. Most of the 4 wheel drive vehicles I've been in have been all time 4x4. Why isn't a Jeep that way? (Besides the fact that the gas mileage is already bad enough?)

[AKULARED]

Yeah bruddah,
the gears turn at slightly different rates so the occasional slip keeps you from tearing up your differential

[blupupher]

Originally Posted by CoriolisSTORM

just a question related to this guys. Most of the 4 wheel drive vehicles I've been in have been all time 4x4. Why isn't a Jeep that way? (Besides the fact that the gas mileage is already bad enough?)

It is a design, use thing.
AWD and 4wd are diffeent things. AWD allows each wheel/axle to turn at different rates via some type of limited slip/clutch/viscious coupling device on the transfer case. They work fine for street and trail driving.
A 4x4 system has a transfer case that locks the front and rear driveshafts together. 50% of the power going to each driveshaft. Ususaly the t-cases are stronger, and usualy will have a low range.
There are other differences, but these are the basics.

[redneckjeepr]

Originally Posted by CoriolisSTORM

just a question related to this guys. Most of the 4 wheel drive vehicles I've been in have been all time 4x4. Why isn't a Jeep that way? (Besides the fact that the gas mileage is already bad enough?)

AWD is for volkswagon cars, 4WD is for JEEPS

[airduds]

50% of the power going to each driveshaft.

This is semantics and I hesitate to even say it but differentials and transfer cases don't necessarily send equal power to each axle or driveshaft. They send equal torque to each axle or driveshaft.

If you jack up one side of your jeep with an open rear diff in 2wd and put it in gear the tire in the air will spin freely and the other won't move. Both tires are receiving equal torque. The torque isn't enough to make the wheel on the ground turn. Without motion, there is no power. So while both wheels are receiving equal torque only the jacked up wheel is being powered.

[Jim Shanks]

I understand what you are saying with regards to an axle. But the tcase.. isn't it driven by a chain? that is engaged and locked "fully" when the handle is pulled up?

Jim

[crgrissom]

Originally Posted by airduds

This is semantics and I hesitate to even say it but differentials and transfer cases don't necessarily send equal power to each axle or driveshaft. They send equal torque to each axle or driveshaft.

If you jack up one side of your jeep with an open rear diff in 2wd and put it in gear the tire in the air will spin freely and the other won't move. Both tires are receiving equal torque. The torque isn't enough to make the wheel on the ground turn. Without motion, there is no power. So while both wheels are receiving equal torque only the jacked up wheel is being powered.

(Assuming you are only jacking up one rear wheel...) Now try the same thing in 4wd, and then try it in an AWD vehicle. This will clearly illustrate the difference. In the first case, just be sure there is no danger when your Jeep drives off the jack.

Chuck

[ShadowKntSDS]

Originally Posted by airduds

This is semantics and I hesitate to even say it but differentials and transfer cases don't necessarily send equal power to each axle or driveshaft. They send equal torque to each axle or driveshaft.

If you jack up one side of your jeep with an open rear diff in 2wd and put it in gear the tire in the air will spin freely and the other won't move. Both tires are receiving equal torque. The torque isn't enough to make the wheel on the ground turn. Without motion, there is no power. So while both wheels are receiving equal torque only the jacked up wheel is being powered.

For the Jeep transfer case, the front and rear output shafts are rotating at the same speed, and do not nessisarily deliver equal power. If the rear is slipping, the the front gets the power, but both will be spinning at the same speed. The jeep's transfer case acts more like a spool than a diff. This exactly why you DONT drive in 4wd on pavement. Any minor differences in the front/rear tire size will cause the vehicle to want to spin the axles at different speeds, but the tranfers case wont let them.

On an open diff, if you jack up the rear end in 2WD, and rotate one wheel the other wheel will want to spin the other way. This is because the average rotational speed of the two wheels must equal the speed of the drive shaft. Since the drive shaft isn't moving, +1 rpm (forward raotation) and -1 rpm (backward rotation) cancel out.

AWD, 4wd part time, and 4wd full time systems are very differnt. Most AWD cars do have a differential between the fron and read drive shafts. Audis for instance have a torsen diff that changes the power delivered to the front/rear. Subaru's claim that 90% of the power goes to rear during takeoff, and 90% to front while deaccelerating.

[Broadway]

All that being said, we still take our rigs out in 4WD and go through some seriuos tranfer case torture i.e. rock climbing and so on. Is the low speed of 4 wheeling having a lesser harmful affect than it would on regular driving speed.

[beachedjeepyj]

Originally Posted by CoriolisSTORM

just a question related to this guys. Most of the 4 wheel drive vehicles I've been in have been all time 4x4. Why isn't a Jeep that way? (Besides the fact that the gas mileage is already bad enough?)

well my old zj was a 4x4 and had 4 wheel drive all the time. the t case only had 4lo N 4hi. i really liked it because if i needed it there was no need to shift into it i could go straight on a trail then straight to the street. it handled alot better in my opinion on the street too and i havnt been on a trail with a part time 4wd system yet so i cant compare the two.