Top speed with 4wd?

[Hill, Bill E]

55mph seems awfully high for the t-case to spin at in 4hi...

You have to remember, the T-case is already spinning. As long as your rear wheels aren't spinning, or your hubs are open(for vehicles w/lockouts) You are fine to shift on the fly into 4 HI. And as far as running w/hubs locked, I lock mine at first snow and leave 'em, just shifting the transfercase from 2 to 4. Doesn't hurt anything but milage a little. As long as all 4 tires are the same size your good. The wear is minimal on an open diff. If you have a locker, thats a different story.

[LumberJack]

Just something to keep in mind. If you are thinking of shifting into four wheel drive for bad roads on the highway I would think again. I have seen way too many 4x4 on there sides, because they where going above 40MPH while on highway. When in four wheel drive and you hint an icey spot the vehicle goes into a spin ( 360 ) before you know it. On highways it is safer to stay in 2 WD, You may slide but are less likely to do a 360.

[oros35]

I've comfortably run 65 in 4wd for many miles. I didn't need to, and if you really need it you probably won't be going that fast.

And there right, everything is spinning already, just not locked in. That's why the speed doesn't matter much. (for a TJ that is without lockouts)

Some of the older full time T-cases arn't much different than the part time ones of today. It's some extra wear from the loading from turning but it's not much different than 2wd than in 4wd in a straight line.

[Northstar]

Why exactly would you want 4x4 at 55 mph? If it's slippery the 4wd is not going to help at all at those speeds. Once there is any potential slippage of the tires, the 4wd can't do anything rapidly enough to keep you straight. Even the automatic all wheel drive on the new trucks has a tiny lag to it when it senses slippage, at 55 things just happen too fast. And with a short wheelbase bad things happen twice as fast.
The way I look at it, 4wd is for traction, getting out of slippery spots or for wheeling. AWD is more suited to what you want to do. If you just want it to make you feel more comfortable, it probably won't hurt but you're wasting fuel and wear on parts. Of course, when you spin out of control and go down in the ditch, you can drive back out without going to all the trouble of engaging 4wd. Personally, even when offroad I don't touch 4wd until I need to continue on. Like to know how far 2wd takes me, and I like having the 4wd kept in reserve to save me. Even when snow plowing, I don't use 4wd until I have to.

[Northstar]

As a side note, I spent ten years driving tow trucks, we contracted with 7 local Police Agencies including State Police. So I developed my own opinions on 4wds at highway speed in the snow, based on my experience.

If you were to look at it statistically, you could prove that Grand Cherokees are in fact the worst vehicle to drive in the snow, as opposed to being the best. This statistic could be supported by the fact that while they account for less than ten percent of the vehicles on the road, they account for more than a quarter of the vehicles upside down in the ditch during a snowstorm.
Don't even get me started on the way every manufacturer advertises their 4WDs and AWDs blasting through snow at high speed in a completely irresponsible manner.

[oxcj5]

I agree with Northstar....

When I started wheeling I thought 4wd was always supposed to be in.

The guys I ran with frowned on it for trail rides. That is unless you are doing an obstacle, or hitting a mudhole trying to get stuck.

"If you get stuck while in 4wd what are you gonna use to get unstuck" "winching takes too long"

[Mozman68]

As a side note, I spent ten years driving tow trucks, we contracted with 7 local Police Agencies including State Police. So I developed my own opinions on 4wds at highway speed in the snow, based on my experience.

If you were to look at it statistically, you could prove that Grand Cherokees are in fact the worst vehicle to drive in the snow, as opposed to being the best. This statistic could be supported by the fact that while they account for less than ten percent of the vehicles on the road, they account for more than a quarter of the vehicles upside down in the ditch during a snowstorm.
Don't even get me started on the way every manufacturer advertises their 4WDs and AWDs blasting through snow at high speed in a completely irresponsible manner.

I think that is more a symptom of drivers being over confident in the ability of their vehicle....I always notice that vehicles that have slid off the road are SUV's....people going too fast in a too heavy vehicle.

My Commander kicks *** in the ice and snow...the TJ...well...it slides quite a bit.

[Hill, Bill E]

All good points. I prefer 4wd on slippery roads(at a safe speed-not 55+)Becuase the front end pulls, helping to keep you striaght. And we can't forget the old addage.."Four wheel drive can get you going faster, but it won't help you stop any faster" I think it all comes down to personal preferance and driving skill. I lock my hubs at first snow just so they are locked in, then use the T-case as needed. Usually 2wd is fine, and 4legged drive is just a lever away.

[tomsjeep]

I have in years past gone 50 mph in 4wd hi with little obvious problems... but it seemed to contribute to some premature axle wear in front.
I cannot imagine trying to do 65+ in 4wd.
But then, individual skill (and foolishness) is always a factor.

I keep it under 45 in 4wd nowadays.
If I get there early, is someone going to take my parking spot?

[FUBAR]

you can run 4X4 at any speed you want. i've run 4X4 at highway speeds in the snow and got great traction. never had a problem with it. think about this a minute...there are vehicles that are FULL TIME 4X4...howinthehell do they run on the highway if you can't run 4X4 over 40 MPH.

this thread is proof you shouldn't believe everything you read on an internet board.

word........