Makes for a very flexible schedule at times, LOL
How to use 4x4
Fleet Mechanic
Joined: Jan 2009
Posts: 1,964
Likes: 2
From: Fort Worth
Let me clarify why what you think may be myths are actually not myths but realities...
Starting with the Dodge axle, the drivers side front wheel is permanently connected to an axle shaft which runs to the differential. The passengers side has a two piece axle, one half permanently connected to the wheel, one half connected to the differential. The two halves are connected together for 4WD by a vacuum assembly. In 2WD, the axle disconnect keeps the two passenger side axle halves independent. The driver side axle happily spins the side gear in the differential, but because the differential is open and there is no solid connection on the passenger side, the side gear simply spins the diff's spider gears, which then spin the passenger side inner axle shaft backwards.
With the exception of the old NNP203 fulltime setup or the later explorers and such that used AWD, 4WD's today have some sort of unlocking system, whether its vacuum, electro servo, torque loading hubs, or manual hubs. Now I will be one of the first to admit that at times I wonder WTF the manufacturers were thinking when they designed something, I also know that for the most part they don't just go and spend money for the heck of it. Lock-out hubs are in that category. If there was no wear issues, handling issues, etc. the manufacturers would not waste the money, time, and manpower to try and come up with unlocking hubs. In the case of automatic systems, those are designed with soccer moms in mind that just want to be able to push a button and have 4wd without having to get out and lock the hubs in, but if full time hubs were the way to go, they would just put the button on the dash and lock up the hubs and forget wasting money on vacuum modules, servos, etc.
With the hubs locked, you are spinning both the axle shafts, the front driveshaft, and the internals inside the transfer case. Each of those items takes a little bit of energy to spin, that is energy that could be spent moving the truck down the road. While it may seem minimal, over time it does add up. Now on the old full time system, the T-case actually used a differential assembly inside it, with hubs locked all the time. On those, going to a lockout kit would raise your fuel mileage by 2-3mpg, as I found out on my 78 Bronco. On the newer systems, there is not as much drag, but even at 3/4 mpg difference, if you drive only 5000 miles per year, at $3.00 per gallon thats an extra $100 bucks in your pocket. Plus, there's an old saying in racing that free horsepower is the best horsepower. This falls in the same category. To get that extra hundred in your pocket, all you have to do is unlock the hubs that are already there (unless you are one of the people who happen to have auto hubs that are sticking)
Are you going to worry about that 100 dollars a year when you can't engage 4wd when you want to?
While a locker in a front end can be a unique experience, especially if you are off roading and overpower the throttle (at that point, you are not steering, you are aiming and hoping it goes in that direction, LOL) the steering issues come in from the U-joint spinning while the hubs are locked and being at the extreme end of its pivot capability. Each the u-joint goes to roll over, it has to actually reduce the angle between the shafts so it can do so, when it forces the angle reduction, the wheels will momentarily try and turn back in the opposite direction just a hair and it will also try and turn the wheel back in your hands a bit.
Anytime you have moving parts, you are going to get wear. If oil and lube was perfect, we would never have to rebuild a motor or have cranks turned for .010 bearings, etc. In the case of the front end, not only are you spinning the ring and pinion against each other and the bearings inside the front end. But in the case of the u-joints you are also putting alot of stress and wear on them, especially when turning. Each time you turn, the u-joint body places a side load against the needle bearings inside the caps, and in the hard lock turns, the needle bearings are literally being hammered by the body. If wear wasn't an issue, consider this, if you needed a replacement part from the JY would you buy one with 100,000 miles or the one with only 10,000 miles on it?
Didn't say wear wasn't an issue. Look at it this way, do you want to pick up the part that has been used frequently, or do you want the part that has been sitting without being used for a couple of years?
VERY GOOD POINT!!
Locking the hubs in and then driving around in 2wd will allow the gear oil to climb and cover the ring and pinion and bearings, and will rotate the needle bearings inside the u-joint and move the grease around, giving good coating on the needle bearings and u-joint shafts.
A week is a bit excessive, even for one that sits. All you really need is to get the fluids moving and coated on everything. A couple trips around the block, or driving to work one morning with them engaged once a month is really all you need.
I keep my engaged throughout the winter because we live in the mountains. I might need 4wd randomly. During the rest of the year, I lock them and then leave them until I think about it again, usually a week or so.
This is not good to do and does nothing to lube any parts. The T-case is fully lubed when driven in 2WD, and the rest is lubed from the hubs spinning the front diff and driveshaft. When in 4WD your torque load is placed against the face of the gear tooth, which is the tooth's strongest point. The problem with locking the case and not the hubs is each time you let off the throttle you take all the rotational force coming from the spinning parts and shock load it against the ring and pinion in its weakest area, the backside of the teeth.
The couple miles of flat, straight road coming into my driveway offers no place where I need to slow. I bet you that when it comes time for me to move my lever into 4h though, it won't be frozen in place from not being used, like I have seen posts on here before.
One last thing, I see you are in Afghanistan right now, so watch your A$$!! and get back home safe! If you make it down to SC, the beers on me
We're moving from Washington state to Arkansas right now. My wife has the horse trailer and F250 and she's hauling all our stuff, plus the motorcycles in the back of the pickup. She briefly muttered something about 8mpg before I hung up lol. I like South Carolina; I lived there for a few years outside of Charleston in Goose Creek. I'll probably make it out that direction again eventually, if not just to take my wife to Myrtle Beach.
The automatic hubs depend on torque from the axle to overcome a spring and lock in, once engaged, they will (in theory) stay engaged until the torque is released, the spring assembly will then unlock them again.
Starting with the Dodge axle, the drivers side front wheel is permanently connected to an axle shaft which runs to the differential. The passengers side has a two piece axle, one half permanently connected to the wheel, one half connected to the differential. The two halves are connected together for 4WD by a vacuum assembly. In 2WD, the axle disconnect keeps the two passenger side axle halves independent. The driver side axle happily spins the side gear in the differential, but because the differential is open and there is no solid connection on the passenger side, the side gear simply spins the diff's spider gears, which then spin the passenger side inner axle shaft backwards.
With the exception of the old NNP203 fulltime setup or the later explorers and such that used AWD, 4WD's today have some sort of unlocking system, whether its vacuum, electro servo, torque loading hubs, or manual hubs. Now I will be one of the first to admit that at times I wonder WTF the manufacturers were thinking when they designed something, I also know that for the most part they don't just go and spend money for the heck of it. Lock-out hubs are in that category. If there was no wear issues, handling issues, etc. the manufacturers would not waste the money, time, and manpower to try and come up with unlocking hubs. In the case of automatic systems, those are designed with soccer moms in mind that just want to be able to push a button and have 4wd without having to get out and lock the hubs in, but if full time hubs were the way to go, they would just put the button on the dash and lock up the hubs and forget wasting money on vacuum modules, servos, etc.
With the hubs locked, you are spinning both the axle shafts, the front driveshaft, and the internals inside the transfer case. Each of those items takes a little bit of energy to spin, that is energy that could be spent moving the truck down the road. While it may seem minimal, over time it does add up. Now on the old full time system, the T-case actually used a differential assembly inside it, with hubs locked all the time. On those, going to a lockout kit would raise your fuel mileage by 2-3mpg, as I found out on my 78 Bronco. On the newer systems, there is not as much drag, but even at 3/4 mpg difference, if you drive only 5000 miles per year, at $3.00 per gallon thats an extra $100 bucks in your pocket. Plus, there's an old saying in racing that free horsepower is the best horsepower. This falls in the same category. To get that extra hundred in your pocket, all you have to do is unlock the hubs that are already there (unless you are one of the people who happen to have auto hubs that are sticking)
Are you going to worry about that 100 dollars a year when you can't engage 4wd when you want to?
While a locker in a front end can be a unique experience, especially if you are off roading and overpower the throttle (at that point, you are not steering, you are aiming and hoping it goes in that direction, LOL) the steering issues come in from the U-joint spinning while the hubs are locked and being at the extreme end of its pivot capability. Each the u-joint goes to roll over, it has to actually reduce the angle between the shafts so it can do so, when it forces the angle reduction, the wheels will momentarily try and turn back in the opposite direction just a hair and it will also try and turn the wheel back in your hands a bit.
Anytime you have moving parts, you are going to get wear. If oil and lube was perfect, we would never have to rebuild a motor or have cranks turned for .010 bearings, etc. In the case of the front end, not only are you spinning the ring and pinion against each other and the bearings inside the front end. But in the case of the u-joints you are also putting alot of stress and wear on them, especially when turning. Each time you turn, the u-joint body places a side load against the needle bearings inside the caps, and in the hard lock turns, the needle bearings are literally being hammered by the body. If wear wasn't an issue, consider this, if you needed a replacement part from the JY would you buy one with 100,000 miles or the one with only 10,000 miles on it?
Didn't say wear wasn't an issue. Look at it this way, do you want to pick up the part that has been used frequently, or do you want the part that has been sitting without being used for a couple of years?
VERY GOOD POINT!!
Locking the hubs in and then driving around in 2wd will allow the gear oil to climb and cover the ring and pinion and bearings, and will rotate the needle bearings inside the u-joint and move the grease around, giving good coating on the needle bearings and u-joint shafts.A week is a bit excessive, even for one that sits. All you really need is to get the fluids moving and coated on everything. A couple trips around the block, or driving to work one morning with them engaged once a month is really all you need.
I keep my engaged throughout the winter because we live in the mountains. I might need 4wd randomly. During the rest of the year, I lock them and then leave them until I think about it again, usually a week or so.
This is not good to do and does nothing to lube any parts. The T-case is fully lubed when driven in 2WD, and the rest is lubed from the hubs spinning the front diff and driveshaft. When in 4WD your torque load is placed against the face of the gear tooth, which is the tooth's strongest point. The problem with locking the case and not the hubs is each time you let off the throttle you take all the rotational force coming from the spinning parts and shock load it against the ring and pinion in its weakest area, the backside of the teeth.
The couple miles of flat, straight road coming into my driveway offers no place where I need to slow. I bet you that when it comes time for me to move my lever into 4h though, it won't be frozen in place from not being used, like I have seen posts on here before.
One last thing, I see you are in Afghanistan right now, so watch your A$$!! and get back home safe! If you make it down to SC, the beers on me
We're moving from Washington state to Arkansas right now. My wife has the horse trailer and F250 and she's hauling all our stuff, plus the motorcycles in the back of the pickup. She briefly muttered something about 8mpg before I hung up lol. I like South Carolina; I lived there for a few years outside of Charleston in Goose Creek. I'll probably make it out that direction again eventually, if not just to take my wife to Myrtle Beach.
The automatic hubs depend on torque from the axle to overcome a spring and lock in, once engaged, they will (in theory) stay engaged until the torque is released, the spring assembly will then unlock them again.
Elder User
Joined: Nov 2010
Posts: 957
Likes: 2
From: Graniteville
- Are you going to worry about that 100 dollars a year when you can't engage 4wd when you want to?
- Look at it this way, do you want to pick up the part that has been used frequently, or do you want the part that has been sitting without being used for a couple of years?
- I keep my engaged throughout the winter because we live in the mountains. I might need 4wd randomly. During the rest of the year, I lock them and then leave them until I think about it again, usually a week or so.
- I bet you that when it comes time for me to move my lever into 4h though, it won't be frozen in place from not being used, like I have seen posts on here before.
- We're moving from Washington state to Arkansas right now. My wife has the horse trailer and F250 and she's hauling all our stuff, plus the motorcycles in the back of the pickup. She briefly muttered something about 8mpg before I hung up lol. I like South Carolina; I lived there for a few years outside of Charleston in Goose Creek. I'll probably make it out that direction again eventually, if not just to take my wife to Myrtle Beach.
Oh and YES AUTO HUBS SUCK!!! LOL
Junior User
Joined: Jun 2010
Posts: 95
Likes: 0
Any jeep produced after about 1992 doesn't have any sort of locking hub or axle set up. My 1997 is incapable of unlocking any portion of the 4wd system, other than the transfer case.
You'll be fine leaving them locked in, and you most likely won't notice any difference in mileage...other than the extreme long term as stated before. You're not going to notice a difference in wear on front end parts...unless your wheel joints are on the edge of failure anyways.
I'd rather gamble on wearing out a wheel joint instead of having to pay to get yanked out of a ditch because I couldn't lock in 4wd when I needed to.
You'll be fine leaving them locked in, and you most likely won't notice any difference in mileage...other than the extreme long term as stated before. You're not going to notice a difference in wear on front end parts...unless your wheel joints are on the edge of failure anyways.
I'd rather gamble on wearing out a wheel joint instead of having to pay to get yanked out of a ditch because I couldn't lock in 4wd when I needed to.
Fleet Mechanic
Joined: Jan 2009
Posts: 1,964
Likes: 2
From: Fort Worth
I wouldn't go to bike week anyways. It's not my style. I love riding windy roads with a couple friends. I don't like the big get togethers. Too many *******es with too much money to spend all in one place who really don't ride. When you have someone rolling in with a truck/trailer with a Harley bagger on the back, you know they aren't real riders.
Elder User
Joined: Nov 2010
Posts: 957
Likes: 2
From: Graniteville
I wouldn't go to bike week anyways. It's not my style. I love riding windy roads with a couple friends. I don't like the big get togethers. Too many *******es with too much money to spend all in one place who really don't ride. When you have someone rolling in with a truck/trailer with a Harley bagger on the back, you know they aren't real riders.
Speaking of twisty roads, have you ever done "Tail of the Dragon"? 318 curves in 11 miles!!!
Tail of the Dragon at Deals Gap and Cherohala Skyway, Graham Co, NC
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FTE Chapter Leader
Joined: May 2006
Posts: 11,273
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From: North Dakota
IDK guys, But if a front axle is sealed and filled properly, there should be no reason to "spin" it from time to time to keep it lubed..
There will always be a oil film on everything up there no matter how long it sits.. If the lockouts are clean, and no moisture in there they shouldn't have to be turned untell they are needed.. I only lock mine in 4x4 when I need it, and I've never had a failure.
If maintanance is kept up on everything, it sould always work when you need it.
There will always be a oil film on everything up there no matter how long it sits.. If the lockouts are clean, and no moisture in there they shouldn't have to be turned untell they are needed.. I only lock mine in 4x4 when I need it, and I've never had a failure.
If maintanance is kept up on everything, it sould always work when you need it.
Elder User
Joined: Nov 2006
Posts: 973
Likes: 2
From: Texas
At some point im gonna be swapping a dana 60 under my truck, and it will have solid drive flanges. There is no downside to having the front axle turn at all times. Just because a u-joint doesn't turn, doesn't mean that it wont wear. It will fail either way. And i would rather feel the vibration starting and replace it, rather then locking the hubs when i need it and having a seized u-joint and be stuck.
And it eliminates one more thing to fail when you need it most.
And it eliminates one more thing to fail when you need it most.
Elder User
Joined: Nov 2010
Posts: 957
Likes: 2
From: Graniteville
Here's a simple test for all those that think there is no downside to having an axle locked in all the time. Go out and jack the truck up in the front and put it on some jack stands, lock the hubs in, and then slide under it on the creeper and turn the driveshaft by hand. Now unlock the hubs and do the same thing. Which time is it easier to turn the driveshaft? Now take the wheels and turn them all the way to the left and have someone roll the wheels over while you look at the angles the u joint is operating at. You don't think operating at that extreme angle is going to put wear on the u-joint? If those kind of angles aren't hard on a u-joint, then why do they put double cardigan joints in the Broncos and such with extreme angles and short driveshafts? Ever seen one of those pavement queens with umpteen inches of lift and 44" tires with the driveshaft angles looking like this \ without the cardigan joints in it, or the axle spun to correct the drive line angle? Ask the guy what happens if he stomps on it, and how often he changes the joints if he actually tries to drive it an appreciable amount.
I think that has got to be the most unique argument for leaving the hubs locked in on a front axle that I have heard. HOW do you figure that an unused part is going to show wear and fail? Using that theory, whats the shelf life on a U-joint at the parts store before its already worn out and failure prone from just sitting on the shelf too long?
FYI, the vibration you are feeling is coming from the u-joint failing do to abuse and improper maintenance from leaving it locked in all the time, and letting it exceed its operating angles everytime you turn the wheels. If you were to maintain it properly by locking the hubs in periodically and driving a short distance to keep the grease coating everything. You would find the life span greatly increased. A properly maintained u-joint is NOT going to seize up.
FWIW, in almost 2.5 MILLION miles of driving I have had exactly THREE u-joint failures. One in my 67 Mustang from a out of balance drive shaft and TWO in the D44 in my 78 bronco before I changed over to the lockout and got rid of the full time set up. As for ones that have just worn out, I have had THREE more there, one in the cardigan joint on the rear shaft on the bronco (which we found was a plugged grease hole in the u-joint cross, so it wasn't greasing properly) and TWO (the same position twice) on my Pete when it was still fairly new, which was found to be an improperly adjusted air suspension that had the angles out of whack.
I think that has got to be the most unique argument for leaving the hubs locked in on a front axle that I have heard. HOW do you figure that an unused part is going to show wear and fail? Using that theory, whats the shelf life on a U-joint at the parts store before its already worn out and failure prone from just sitting on the shelf too long?FWIW, in almost 2.5 MILLION miles of driving I have had exactly THREE u-joint failures. One in my 67 Mustang from a out of balance drive shaft and TWO in the D44 in my 78 bronco before I changed over to the lockout and got rid of the full time set up. As for ones that have just worn out, I have had THREE more there, one in the cardigan joint on the rear shaft on the bronco (which we found was a plugged grease hole in the u-joint cross, so it wasn't greasing properly) and TWO (the same position twice) on my Pete when it was still fairly new, which was found to be an improperly adjusted air suspension that had the angles out of whack.
Elder User
Joined: Aug 2003
Posts: 828
Likes: 0
From: Bellingham, WA
Any jeep produced after about 1992 doesn't have any sort of locking hub or axle set up. My 1997 is incapable of unlocking any portion of the 4wd system, other than the transfer case.
You'll be fine leaving them locked in, and you most likely won't notice any difference in mileage...other than the extreme long term as stated before. You're not going to notice a difference in wear on front end parts...unless your wheel joints are on the edge of failure anyways.
I'd rather gamble on wearing out a wheel joint instead of having to pay to get yanked out of a ditch because I couldn't lock in 4wd when I needed to.
You'll be fine leaving them locked in, and you most likely won't notice any difference in mileage...other than the extreme long term as stated before. You're not going to notice a difference in wear on front end parts...unless your wheel joints are on the edge of failure anyways.
I'd rather gamble on wearing out a wheel joint instead of having to pay to get yanked out of a ditch because I couldn't lock in 4wd when I needed to.
Just to give you a heads up. They stopped using hubs in wranglers in 86, All of the YJ models have a CAD. (Central Axle Disconnect)
Junior User
Joined: Apr 2010
Posts: 67
Likes: 0
Thanks for the education fellas. I can change oil, brakes, tackled a clutch a couple of times, water pump, starters, alternators, and bit more, but come to a grinding halt after that.
Never would have guessed you could leave the locking hubs locked and in 2wd. Which leads to another question:
1. With my hubs locked and in 2wd (F25O HD) do I need to stop and shift in 4wd? under 20mph, highway speeds? How about shifting out of 4wd. thanks, Keystonepaul
Never would have guessed you could leave the locking hubs locked and in 2wd. Which leads to another question:
1. With my hubs locked and in 2wd (F25O HD) do I need to stop and shift in 4wd? under 20mph, highway speeds? How about shifting out of 4wd. thanks, Keystonepaul
Freshman User
Joined: Jun 2010
Posts: 32
Likes: 0
From: Sykesville, PA
No you do not have to stop. just push in the cluth and shift or if you have an auto let off the gas and shift. The exception is 4 low. you gotta be stopped or going real slow. Im in and out of 4 hi all the time at highway speed in the winter.
Junior User
Joined: Jun 2010
Posts: 95
Likes: 0
I was referring to the end of the CAD system also. I don't know much about the wrangler years, I've had a few Cherokees though.