Max speed in 4wd high

[Pudge]

I came from a 1500 into my current 2021 PW. No longer do I have that auto 4wd High and I’m either in 2wd or 4wd. Winter is finally here and when I’m on the highway, how fast is everyone going in 4wd before it’s to much? Or does it matter?

 

[670hoth]

Good question! I don't know the answer but am interested in what people say. Last weekend I was on the interstate in 4wd high in slippery weather doing 60ish for about 30 miles and started to get some sort of smell in the truck. I put it back in 2wd and slowed down a bit and it went away.

 

[pacofortacos]

I have used it at 74+ mph often, as long as the road is straight or slippery there isn't any issue.
However I have a 1500 with the same type as transfer case as you but I think a slightly different model.

All 4 tires need to be the same size with about the same amount of tread left on them.

In my Outdoorsman, I have a stupid push button switch that I hate to go from 2 to 4 Hi. It takes too long to respond and I have to search for it. My old Dakota had a rotary switch which you could easily feel for, flip 1 position and not take your eyes off of the road.
What does the PW have?

 

[CanRebel]

I came from a 1500 into my current 2021 PW. No longer do I have that auto 4wd High and I’m either in 2wd or 4wd. Winter is finally here and when I’m on the highway, how fast is everyone going in 4wd before it’s to much? Or does it matter?

Same speed as 2wd.
I don't have PW, have Rebel, doubt any different.
max speed I drove in 4wd was 170km, was no different than 2wd.
I wouldn't say you should drive in bad weather just cause your in 4w though.

 

[Grand Mesa]

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[crazy jerry]

going high rate of speeds on snow/ice/mud etc , whether in 4wd or not ,is stupid and down right foolish. best case, you go in the ditch and only hurt yourself. worst case , you go in oncoming cars and hurt some law abiding hard working person just trying to get home.
when you shift to 4hi at high speeds the electro clutch engages the tcase chain, front driveshaft and ring/pinion and goes from zero to what ever speed your doing , in a instant. over time im sure its hard on parts. open the owners manual sometime and get learned up. i think it says 55mph top engagement speed. yes im sure it will engage at higher speeds but thats alot of mass to go from 0mph to 70mph instantly.
now if you engage it at 55mph or below, and just want to know how much faster you can go before the tcase explodes, aparently grandmesa says your fine atleast 80mph

 

[Grand Mesa]

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[crash68]

Mechanically the 4X4 system won't care how fast you go, in low range you'll run out of engine rpms.
You now have a part-time transfer case that can effect how the vehicle steers. Chances are if you need to use 4X4 there isn't the need to go fast.

 

[Rado]

I think the manual say 55 MPH recommend Max speed in 4x4 mode,
But I see many of you have used it higher speeds w/o damage !
For me I drive in grandpa mode in ice and snow but I am a old fart lol
Found this link interesting !

Here's How Fast Can You Drive In 4x4 High? - Four Wheel Trends

How fast can you drive in 4 high when you have a Liberty? It’s not recommended that you go much over 45 mph.

fourwheeltrends.com

 

[retired]

number one cause of accidents on slick roads....speed. If you have an accident on a slick road you are driving too fast for conditions....here they always publish the contributing factors in fatalities and generally speed is the first contributing factor. your power wagon will weight somewhere around 7500lbs with a driver give or take. that is a lot of momentum. I have been driving in snow country since the early 70's..knock on wood after the first winter or so have kept it on the road......slow down don't use cruise control and just smile and wave when you go by the guy who flew by you and went into the ditch.....

 

[392DevilDog]

The number one cause of accidents on slick roads is...what made the road slick. You can slide off a slick road in neutral.

Just saying.

 

[392DevilDog]

As mentioned if conditions warrant 4wd. You should slow down and be cautious.

That said. When the roads are wet from rain and you want to proceed with no tire spin. 4wd will work at any speed you want to travel.

You can also engage it at any speed. The shift will not be made until all speed sensors read the same...best to lift off the throttle and coast pulling on the lever and not getting back on the throttle until your 4wd light is solid.

It is always best to engage 4wd moving...as your truck has a CAD axle and needs the movement for the axle spline to mesh with the collar.

4wd low is obviously a different beast. You need to be in transmission neutral for engagement. And coasting under 5 mph for easiest engagement.

The new 8 spd transmission allows for higher speeds in 4wd low. Watch some Powerwagon test videos from RAM to see them launch it into the air.

 

[Grand Mesa]

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[Grand Mesa]

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[Pudge]

Thanks all for your thoughts. I’ve been through the 2021 2500 manual and it doesn’t state anywhere what the max speed for engagement is, nor top speed in 4wd. so I just wanted to know what you guys do.

 

[Rado]

number one cause of accidents on slick roads....speed. If you have an accident on a slick road you are driving too fast for conditions....here they always publish the contributing factors in fatalities and generally speed is the first contributing factor. your power wagon will weight somewhere around 7500lbs with a driver give or take. that is a lot of momentum. I have been driving in snow country since the early 70's..knock on wood after the first winter or so have kept it on the road......slow down don't use cruise control and just smile and wave when you go by the guy who flew by you and went into the ditch.....

I agree 110%. I se that all the time here in Maine. On Icy snow covered roads I get passed by people doing 70 /80 mph :O and have seen them in the ditch later :O , Drive for the conditions and get there in one piece

 

[62Blazer]

Really no top speed in 4 High in regards to the mechanical system, but as mentioned several times above if you need to be in 4 wheel drive because the roads are slick than you shouldn't be driving that fast anyway. With that said I have been up to probably 70 mph for short distances but that was because I hit a section of freeway that was clear and dry before it got snow covered again. Always remember that 4wd helps during take off and can help with straightline stability (keeps the truck from wanting to start fishtailing), but it doesn't make the brakes better and as soon as you take your foot off the throttle there is no difference between 2wd and 4wd. I spent about 10 years as an durability test engineer performing work for a large manufacturer. We would put 25,000-50,000 miles performing powertrain durability testing on trucks and half of those miles were in 2wd and half in 4wd while running the exact same procedure with speeds up to 99 mph and same course which was mostly paved or concrete. We rarely ever saw any failures that were directly related to running in 4wd under those conditions.

 

[IDSandman]

4wd can be run at any speed that 2wd can. I always engage it under 55 and with my foot off the gas coasting as to not have torque on the drive train.
As far as conditions, drive at your comfort/ability level. Judging by some of the comments, my comfort/ability level is higher than others. I do run dedicated winter tires to help with traction in winter conditions.

 

[2003F350]

4wd can be run at any speed that 2wd can. I always engage it under 55 and with my foot off the gas coasting as to not have torque on the drive train.
As far as conditions, drive at your comfort/ability level. Judging by some of the comments, my comfort/ability level is higher than others. I do run dedicated winter tires to help with traction in winter conditions.

I CAN drive 55+ back and forth to work in 4WD. There isn't much traffic usually, since it's all rural roads, and if conditions are crappy schools are cancelled too.

But I don't. Because if there's snow on the ground and/or coming down, there is always the possibility of there being something in the road that I can't see, and traveling at that speed in those conditions will make my truck react slower than on dry pavement. I'd rather be able to react to unknown variables safely instead of destroying my truck.

 

[IDSandman]

I CAN drive 55+ back and forth to work in 4WD. There isn't much traffic usually, since it's all rural roads, and if conditions are crappy schools are cancelled too.

But I don't. Because if there's snow on the ground and/or coming down, there is always the possibility of there being something in the road that I can't see, and traveling at that speed in those conditions will make my truck react slower than on dry pavement. I'd rather be able to react to unknown variables safely instead of destroying my truck.

Ok. ‍
Everyone should drive to their ability/comfort level for the conditions like I said.