running in 4wd on road??

[GYShah]

After reading all these posts, Im wondering now : is there any advantage or disadvantage to keeping the front axle engaged on the road if you have a selectable front locker and keep it unlocked? So you would be open diff in the front axle. Would that help on roads? snow? rain?
Or would it just wear out the transfer case?

 

[russellmn]

The only advantage would be that you could easily and quickly engage 4wd. Disadvantages include: increased fuel consumption (its a brick with wheels, you're not gonna sip fuel to begin with) increased wear on front axle, driveshaft and t-case, and who knows what else...

That being said, many newer 4wd vehicles are like this from the factory with no lockouts, front spins all the time.

 

[blubuckaroo]

After reading all these posts, Im wondering now : is there any advantage or disadvantage to keeping the front axle engaged on the road if you have a selectable front locker and keep it unlocked? So you would be open diff in the front axle. Would that help on roads? snow? rain?
Or would it just wear out the transfer case?

Are you asking about leaving the hubs locked, or the transfer case engaged to the front? I leave my hubs locked whenever I head out to wheel. That way the diff is warmed up when I need it. Leaving the transfer case engaged to the front can't be good because Dana and Ford ratios don't match exactly.

 

[broncosbybart]

You would never want to drive a Bronco in 4wd on dry pavement as a habit. With open axles it will still bind on sharp corners, wearing tires and putting undue stress on drivetrain parts. In snow is the only time you'd really want to be in 4wd, and even then it is tire style/condition and vehicle weight that really matter, once you are up and moving.

If you haven't done it, put your truck in 4wd and drive it around a parking lot. You'll see what I mean. Plus, all the reasons mentioned above.

 

[GYShah]

I was talking about the tranfer case but I never thought about the effect of the ratio mismatch
I guess newer all time 4wd drives dont have that issue
But if you have an open diff front end, why do you unlock the front hubs at all??
Or is spinning the open diff harmful too if not engaged to the tranfer case?

 

[KyleQ]

Leaving the transfer case engaged to the front can't be good because Dana and Ford ratios don't match exactly.

Haha, seriously? Have you ever jacked the front axle up while in park and rotated the tire forwards and backwards? There seems to be miles of play - and your worry about 4.10 to 4.11? Tire pressure and wear would make a bigger difference.

The only reason not to leave the hubs locked in at all times is MPG. I would rather have axle shafts and drive shafts spinning at all times as it keeps everything lubricated. I've found way too many steering joints completely locked up because the front axle never gets locked in, drive shaft joints and seize up from sitting with corrosion on them. U-joints need to spin to force the grease into the needle bearings to keep them alive.

If I were to drive on the freeway or long distances (25+ miles) I would unlock the hubs, but beyond that, they stay locked.


Driving with the hubs locked in with an air locker in the engaged position will hurt driving performance, unlocking it take it out of the picture, you won't even notice it's there - I'm doubting you would ever want that thing locked on the street either... Have fun and enjoy your Bronco. If you ever tear into your D20 or D44 and realize how fail proof they are you might change your habits.

 

[bmc69]

I was talking about the tranfer case but I never thought about the effect of the ratio mismatch
I guess newer all time 4wd drives dont have that issue
But if you have an open diff front end, why do you unlock the front hubs at all??
Or is spinning the open diff harmful too if not engaged to the tranfer case?

Full time 4wd vehicles always have another set of differential gears between the front and rear. The EB does not.

I do engage the hubs on the front dif periodically while driving on the road, to make sure all the moving parts get some exercise and lubricating oil splashed around..but not if its a LS or auto locker front dif.

 

[GYShah]

ok
im learning a ton of stuff here!
so what is going on in the dana 44 front without a locker when you lock the hubs but dont engage the tranfer case?
is it acting like an open diff? or just 2 independently spinning axles? or spinning together?

 

[Broncobowsher]

Lockout hubs were originally an option. If everything is in good shape in the front you can leave them locked. In many parts of the country the hubs got locked in at first frost and stayed locked until spring thaw (back when everything had lockout hubs).

You drove around in 2WD until you needed 4WD, slip the transfer case into 4WD and when done go back to 2WD. Using 4WD is like using windshield wipers, you use it when you need it. Having the hubs locked in is like having good wiper blades.

 

[Heus33]

Lockout hubs were originally an option. If everything is in good shape in the front you can leave them locked. In many parts of the country the hubs got locked in at first frost and stayed locked until spring thaw (back when everything had lockout hubs).

You drove around in 2WD until you needed 4WD, slip the transfer case into 4WD and when done go back to 2WD. Using 4WD is like using windshield wipers, you use it when you need it. Having the hubs locked in is like having good wiper blades.

Thats the best analogy I've read. Nice job bowsher.

 

[BroncoDawg]

The OP was asking about leaving the TC locked along with the hubs. Leaving the hubs locked (with TC in 2 WD) is harmless except not meant for high speeds. Locker, limited slip or open makes no difference because with no power to the axle the locker doesn't lock up, it just free wheels.

Where the problem lies is having the TC engaged and hubs locked because the front and rear axles are now gear locked together and when you make a turn the front wheels turn far less than the rear creating bind, that is only released by tire chirping. The bind is released in dirt because of the slick surface, but on asphalt the bind between the two driveshafts can continue on. That's why shifting out of 4by is tough at times...Bind.

As said earlier most trucks and 4x4s have no slip ability in the transfer case like all wheel drive vehicles do, so can't run in 4x4 on DRY hwys.

Hope that helps answer the OP's question.

 

[GYShah]

that analogy makes alot of sense!

 

[KyleQ]

The OP was asking about leaving the TC locked along with the hubs. Leaving the hubs locked (with TC in 2 WD) is harmless except not meant for high speeds. Locker, limited slip or open makes no difference because with no power to the axle the locker doesn't lock up, it just free wheels.

If the front end had a lunchbox locker, engaged ARB or Ox the tires will bind when turning - if the hubs are locked in the gears and drive shaft is spinning, it acts the same weather the TC is providing power or not. Even without a drive shaft the tires will scrub.

 

[russellmn]

Kyle, I've driven WAY too many XJ/YJ/TJ/JKs with locked fronts that were TRANSPARENT on the road to believe that. You may have had something else going on, but if the locker isn't seeing torque, it isn't locking. If it isn't locking, you won't even know it's there. A spool you will notice with the hubs locked, but not any kind of ratcheting locker. Selectable lockers are essentially spools when engaged, so you'd notice that.

 

[GYShah]

thanks for all the input
i really dont know where else i could have learned all this!

 

[Broncobowsher]

If the front end had a lunchbox locker, engaged ARB or Ox the tires will bind when turning - if the hubs are locked in the gears and drive shaft is spinning, it acts the same weather the TC is providing power or not. Even without a drive shaft the tires will scrub.

Lunchbox or detroit locker will be transparent. I have done it before. The racheting will allow for bind free turning in 2WD even with the hubs locked in.

Spool or selectable locked will not drive the same (left to right fighting each other, binding in turns)

 

[DanWheeler]

Lunchbox or detroit locker will be transparent. I have done it before. The racheting will allow for bind free turning in 2WD even with the hubs locked in.

Spool or selectable locked will not drive the same (left to right fighting each other, binding in turns)

I'd partially agree with that. With my old Aussie locker, I could jack up one tire in the air (with hubs locked) and grab around it and if I pushed/pulled hard enough it would break lose and spin/ratchet. I thought I tried the same thing with the detroit but I dont remember it doing the same thing.