Better to tow in 2wd or 4wd

[freddyray21]

Re: Better to tow in 2wd or 4wd

each can have an opinion. I just know 4 low is tough on all moving parts when on pavement.

 

[freddyray21]

Re: Better to tow in 2wd or 4wd

unless you are referring to low gear on the transmission? Not the same as 4 low at least in my vernacular.

 

[NSBCraig]

Re: Better to tow in 2wd or 4wd

No I'm talking about low in the transfer case, and no it's not harder on any moving parts unless you turn.

In fact it is easier on the whole truck because of the fact you don't need to put your foot in it.

You have eliminated all chance of tire slip by smoothly applying torque to them.

You are operating your motor at the correct rpms, so there is no need to stress it and apply more throttle then you really need.

That is what the gear is there for- going up steep grades, towing heavy loads...

It's no different then using an old school granny gear and it's the way your truck is designed ( to give the best on road performance in high gear and offroad/ work time performance in low gear )

 

[QC]

Re: Better to tow in 2wd or 4wd

The only way that going straight in 4WD low (or high) stresses the vehicle is if you have different size tires somewhere in the combination. In fact, it could be argued that it is good for all of those components to get some use once in a while if you don't otherwise use 4WD . . .

 

[jay_merrill]

Re: Better to tow in 2wd or 4wd

Using 4WD - high or low - isn't going to hurt anything as long as the vehicle is driven properly and is driven in a straight line. In fact, and has been pointed out, there can be some advantages in doing so.

It's the matter of the outside wheels and axles having to rotate at different rates when the vehicle is turned, that causes the problem. The front axles of a 4WD have limited slip differentials in them - the entire purpose of those differentials is to deliver as much power to both axles as possible, meaning that they will try to rotate nearly in unison. That is not a desirable situation when the outside front tire (and axle) is being forced to rotate faster by the pavement over which it is traveling.

One way to get around this problem, if you have manual hubs on the front axle, is to leave them disengaged and shift into 4WD low. By doing this, the front tires are not going to try to force the axles to rotate together. While you lose the benefit of 4WD, you will put less stress on the engine on a steep ramp, and may be able to make a smoother start.

If you need the 4WD, or have automatic hubs, go to 4WD (either low or high) and drive straight up the ramp, until you reach a point where you can disengage the transfer case and hubs. If you have automatic hubs, you are going to have to go far enough to back up a little to get them unlocked.

For those that have "air lockers" and such, you already know what I am talking about and know what you need to do.

 

[Medic4040]

Re: Better to tow in 2wd or 4wd

Maybe it was said, how about over drive? when if ever should you use that???

 

[QC]

Re: Better to tow in 2wd or 4wd

Probably better as a new topic Medicdude, but the consensus here kinda is if you are a gear head, do whatever you want with OD but try not to apply full load. If you are more of a point it and go guy, run it in direct.

 

[windsors03cobra]

Re: Better to tow in 2wd or 4wd

I turn overdrive off whenever I am pulling 1500#'s or more, I don't have a super duty allison torque shift twin disk super trans, I have a V8 Exploder or Straight Six Grand Cherokee and I don't pull things far so the little extra gas I burn is nothing compared to changing a trans out due to a burned OD clutch, beside my low horsepower rigs will be shifting between 3rd and 4th with every little grade or press of the go pedal.

Our Exploder is AWD all the time, some borg warner case, the Heep is select-trac and can run full time with center diff open or part time off road with the center diff locked, both trucks have always locked front axle's with CV joints so no u joint like bind, and no MPG savings by unlocking the front axle, 2wd on the Jeep saves no MPG.
The Jeep will bind a bit on dry pavement with the center diff locked. I have chunky mud tires on both so the tires rarely spin.
The trucks are great sno-goers, my wife drives the Exploder in the winter, with its heated seats and V8 it is a preferred ride.

 

[MrPhotographer06]

Re: Better to tow in 2wd or 4wd

i dont have a choice between 2wd or 4wd..all time 2wd..haha

but both my truck and my buddys truck are 4cyl 5spds..

his is a 91 toyota 22re
and mines a 88 dodge dakota

but my boat is also a 14ft glastron fiberglass .. you can almost pick it up by hand

so were okay on our tow vehicles and the towing weight right?

 

[kenmyfam]

Re: Better to tow in 2wd or 4wd

1998 Jimmy.
2WD for general towing. 4WD on ramp. Never found the need for 4WD low yet with my set up.

 

[Silvertip]

Re: Better to tow in 2wd or 4wd

I can't believe how much misinformation is presented here regarding how 4WD works and exactly "what" causes damage. First, a torque converter sits between the engine crankshaft and the input to the transmission. You will not damage it regardless what gear you are in or whether or not the vehicle is in 4WD. It has nothing to do with the 4WD system. Next - the front and rear differentials on any vehicle allow turning whether or not you are in 4WD and whether or not you have a limited slip differential. Taking a 4WD vehicle out of 4WD does not change anything regarding a limited slip differential. It will allow turning in 4WD just fine -- just like it does when in 2WD. Now to the real problem. Those of you that are old enough to remember the older Blazers with the "LOCK" position on the transfer case lever should be familiar with how that system worked. That transfer case had a "differential" in it so if the front wheels and back wheels turned at different speeds (as in you were stuck or turning), the drive shafts were actually turning at different speed. In the LOCK mode, the center differential locked the two shafts together and it was then that you noticed the chatter of wheels as you tried to turn. Many newer vehicles do not have the diff (or clutches) in the transfer case so it is definitely not recommended to go in any direction except straight on dry pavement as you can break things when turning because the front and back wheels do not track in the same path - hence the drive shafts would have to rotate at different speeds and thats the reason for the wheel chattering as they skip around the corner. If all four wheels have bare pavement to grip, something has to give as the tires can no longer skip around the curve. This is really tough on U-joints. My Yukon on the other hand (and other auto-4WD systems as well) do have an AUTO 4WD system that allows driving in 4WD on bare pavement. If any wheel slip occurs it automatically shifts into 4WD in less than a heartbeat. That system can also be locked which now creates a system where the front and rear drive shafts are locked as in a conventional system. In that mode you do not want to drive on bare pavement and make sharp turns. Lastly, unless you have a locking or limited slip rear diff, the best you have is two wheel drive. One front wheel and generally the opposite side wheel in the rear will spin when stuck. As long as three of the four wheels have traction you will not get stuck. Add a rear limited slip and you now have three wheel drive. The two rear wheels will still push even if one has poor traction. Only with front AND rear limited slips do you have true 4WD. There aren't many of those around because of potential handling issues.

 

[MrPhotographer06]

Re: Better to tow in 2wd or 4wd

the diffrence in maunual and auto 4wd is manual 4wd requires you to manally lock the hubs too..you are free wheeling as you dont have 4wd when not locked. when you lock in you are then techiclly connected to the diff.

auto locking hubs have an electro magnet in them so when you "turn on" 4wd the power releases the magentic locking mechanism and it locks into gear.

 

[windsors03cobra]

Re: Better to tow in 2wd or 4wd

I have only seen vacuum hubs (total garbage), mechanical/automatic hubs on older style rigs where a lock out is preferred (kinda rarer today/real trucks got em), Locking hubs where you have to turn the knob to lock or lockout and center axle disconnect style axles, usually vacuum operated (mostly garbage)
GM thermo linear actuated center axle disconnects for the ultimate in absolute rubbish to engage a front axle.

Electric shift motors, push buttons, turn knobs and light bulb 4x4's (garbage).

Haven't seen any electric hubs but just about everything has been tried, the front axle in my Heep Grand Cherokee is always locked, thus taking it out of 4wd really saves no MPG. All the axles always turn, the front driveshaft always turns and when 2wd is selected it simply means the transfer box is not transmitting power to the turning front prop. shaft.
Grab the hand lever and yank it into 4wd and its going to work, not wait for some lights and shift motors to turn, in the cold, snow, wet, salt bomb enviroment.

Older Jeep Rubicon probably the best stocker type 4x4, solid front axle, front locker, rear locker and center locker.

 

[jay_merrill]

Re: Better to tow in 2wd or 4wd

I don't disagree with the issue of front axle rotation v. rear axle rotation, but I can tell you via personal experience that some part time 4WD vehicles will routinely break a hub on one side only, if turned tightly on dry pavement in 4WD. This is particulalry true of some automatic hubs, because they tend to be weaker than manual hubs.

If the only factor at play was the front/rear axle issue, both should break and that would probably happen nearly simultaneously.