I run my jeep in 4hi at highway speeds in snow all the time.....so does everyone I know. To say you have to be driving 40 mph in 4hi is just stupid.

 

Guess it all depends on who you know then But ultimately if things start breaking because you are flying around in PT FWD - its your truck.

 

4hi part time, or 4hi full time?

 

I wanted to make a reply here. NOw before we go any further, please note that I'm not trying to start an argument or fight. I was curious about the 4HI option as well.

I have looked and looked and could not find one line where it says you can't use 4HI on highway. Not a single line that says anything to do with speed on 4hi. It does mention of lost fuel economy but nothing more than that. I just bought my 2013 ram 1500 4x4 tradesman 4.7L brand new (actually just rolled over 1000 miles. Bought it at 13 miles).









this is 2013 owners manual. Unless Ram changed something from the older model, my 2013 model doesn't say ANYTHING about not driving 4WD on highway. I used the 4hi on highway on heavy rain. I was doing 80 mph. No noise, whine, or issues. I'm just curious if older model HAD some restrictions on 4HI that ram recently took off?

 

Seriously? You don't see it. It is in the copy you posted.

It clearly states the 2H is for normal and highway use and 4H and 4L are for loose and slippery road conditions.

If 4H was intended for highway use, why would they not state that 2H & 4H are intended for normal and highway use, and not just 2H? Do you have to be told that you can't do it, to know it is not recommended? I read it as saying that 2H only is for highway, that is what you can safely use.

Heavy rain can be considered "slippery conditions" so as long as you stay within the 55mph (88km/h) it also states, I think you would be fine.

 

It also says operating in 4hi on dry hard surfaces may cause increased tire wear and damage driveline components. Page 5.

 

Yes, but I think they were wanting to see the word "highway", so that is where they have got confused over this.

 

Well folks, last Friday, two months into the silliness, Chrysler informed the local dealership to cover the bills for repairs and other expenses we incurred including towing, and cost of rental for another vehicle. No mention that it is on warranty or it was a mechanical or user error. The costs will be covered. This was after we had talked to a Western Regional Director for Chrysler for about an hour trying to explain what took place.

What we have been told is that we need to always consider that the 4WH is only part-time not full-time. So in saying this, we have changed our policy to not use 4WH all the time on our northern highways just only when we need to start off and if conditions warranted it and we are in speeds lower than 50km.

In our talks with the Director 4WH was definitely discussed but so was the case of a missing oil plug in the transfer case. Another thought was the two new tires that were added on by the dealer. So many variables and even more so brought on by the astute readers and repliers to this thread.

The owners manual shown by previous replier is exactly the same as I have in my 2011 truck. No speeds mentioned but only road conditions.

So we are now waiting for the truck to be repaired. It should take a day or two and then it is back to us. No cost to us.

I will finish off this thread by saying this forum was very helpful in providing more insight into this issue and to hear from some very knowledgeable folks that were both pro and con to the subject. Thanks everyone.

 

Glad to hear! It's a shame you had to go through such hassle, but at least they are taking care of a problem that should be covered.

I would NOT recommend using 4Hi in rain. It's just not meant for that. Hydroplaning happens regardless of how many wheels have power to them and is caused by excessive speed so I dont see a purpose either.
Rain does not provide enough slip for the 4wd to operate safely, especially with the newer tires that have Silica compound in them! Silica enhances wet traction immensely
The manual may state otherwise, but I strongly disagree. I will never use 4wd in the rain.period.

 

So who are you to decide what's loose and slippery condition and what's not? I'm not allowed drive on slippery condition on highway? or Slippery condition only exist on roads less than 40 mph? What if in order to go to work, I must take highway and the roads are slippery? you want me to drive in 2hi and put my life in danger and the chances of me spinning out losing my life and possibly taking someones life with me? no. 4hi is made for slippery condition regardless of speed. granted some may consider "rain" as a slippery condition and they will be darn right too but I don't think driving 4hi on rain is necessary (and it's a bit excessive) but there are various other slippery condition that you CAN (with the amazing snow/mountain grade tires 2013 comes with the narrow 17" wheel) drive as high as 55-60 MPH on highway with 4hi on. If there's 8" of snow, of course i'm not driving more than 30 but for other minimal slippery condition, using 4hi shouldn't be an issue.

We get slippery condition all the time. Take last nights instance: it's been snowing here. about an inch of snow. some places half inch. Is it slippery condition? yes. Can I drive at 55-65 MPH with ease? of course. I have no problem driving on a .5" fresh snow at 55 mph. It doesn't even slip. So you're telling me, I CAN'T use 4Hi because that too high of a mph for it? of course not. I drove at 55-60 with 4hi last night and seriously the grip of those tires and thin 17" rims, I didn't even feel it.

My problem is it doesn't show ANYWHERE on the manual " DO NOT EXCEED over x MPH while you're on 4hi" and if you look at page 389, you can see that the manual DOES tell you that you can be speeding upto 55 mph and switch to 2hi to 4hi. So if it's slippery and you can maintain 55-60 mph (or even higher), you should be able to use 4hi.

Exactly, no speed mention anywhere. All it says, if it's slippery, you can use 4hi. So, if I am driving on a freshly plowed highway and I know there's a thin .5" snow but I know that my truck and tires are capable of doing 65 MPH, I SHOULD BE able to use 4hi there. I'm following chryslers recommendation (4hi if slippery) and driving my own speed (as there's not mention of speed anywhere) If Chrysler wanted us to not drive it, they would specifically say , " DO not exceed more than 40 MPH/50 MPH in 4hi" but they do not. when comes to 4low, Chrysler tells you straight up " do not exceed 25 mph!!!" ( with exclamation point) . do you get my point? glad you got everything squared away.