Ok here's my understanding, as for 4WH or 4WL has nothing to do with the hubs that is just a gear change in the transfer case. As for the auto hubs if you are going in reverse it is possible to un-engage a wheel depending which wheel has the most traction and for driving forward is I believe the opposite. Manually locking of the hubs locks them to the axel but then unless you have a limited slip or a locking diff you are still spinning the tire that has the least traction. Like I said, this is my understanding, I could be wrong.
Auto Locking Hubs explanation
Ok Ive gone through a lot of threads here and cannot find an answer to my question.
I have a 2001 F250 7.3 Diesel. I just replaced both auto locking hubs and wheel bearings. All tested fine and according to my mechanic, all is working normally. I want to know if 4WD low engagement is the same as getting out of your truck and locking the hubs manually. If I have my hubs in the "auto" position, why do I still have to get out and rotate the hubs into manual. Some people are telling me that because of limited slip differential that I dont have full 4WD until I get out and change the hubs to manual. So my question is why have auto locking hubs if I still have to manually change the hubs.
It seems like I have half 4WD until I lock the hubs myself. Then its great. I've gotten stuck in snow many times thinking I have engaged 4WD when I haven't.
Its frustrating when everyone with 4WD is just plowing past you.
Thx anyone
wopr21
I have a 2001 F250 7.3 Diesel. I just replaced both auto locking hubs and wheel bearings. All tested fine and according to my mechanic, all is working normally. I want to know if 4WD low engagement is the same as getting out of your truck and locking the hubs manually. If I have my hubs in the "auto" position, why do I still have to get out and rotate the hubs into manual. Some people are telling me that because of limited slip differential that I dont have full 4WD until I get out and change the hubs to manual. So my question is why have auto locking hubs if I still have to manually change the hubs.
It seems like I have half 4WD until I lock the hubs myself. Then its great. I've gotten stuck in snow many times thinking I have engaged 4WD when I haven't.
Its frustrating when everyone with 4WD is just plowing past you.
Thx anyone
wopr21
1 - 20 of 25 Posts
High and low are just in the transfer case. If you have to get out and engage the hubs manually you have a vacuum leak or the switch by the vacuum pump that controls the hubs is bad.
Term 3 has a pretty good understanding. 4L and 4H is a gear change in the transfer case. Stick it in low and you'll see. The hubs auto lock but as with any open/limited slip differential the least traction is the easiest to spin and it will. Locking them in locks them both, but this is harder on your components because nothing gives. Auto-lock is fine for 90% of the situations manual lock is your maximum traction but harder on your stuff for driving distances.
Since the auto hubs only run off of one vacuum line shouldn't they be both be locked when the truck calls for 4 wheel drive if the system is working correctly? I didn't think that there was any difference between the auto and locking them if they work. Please shed some light on this if I am wrong.
Yes, both hubs lock. the dash knob is just a vacuum operated way of locking the hubs to the end of the axle and also shifts the transfer case. just locking the hubs manually does not put you in 4x4 becasue it does not shift the transfer case (the magic knob on the dash does that too). A full manual 4x4 set up, the transfer case would be shifted with a lever and the hubs would have to be manually turned.Since the auto hubs only run off of one vacuum line shouldn't they be both be locked when the truck calls for 4 wheel drive if the system is working correctly? I didn't think that there was any difference between the auto and locking them if they work. Please shed some light on this if I am wrong.
Unless you installed a limited slip differential in your front axle, you don't have limited slip in the front, just the rear axle. AFAIK, LS was not an option or our trucks in the front axle. So forget about LS in your front.
Locking the hubs (either with the automatic vacuum method on the dash or getting out and turning the knobs) locks your wheels/hubs to the axles. the differential is still a differential. It does not lock the 2 halves of the axle together. The wheel with the least amount of traction will get the most power in an open differential type set up.
check your vac lines for good seal mine had dry rotted, i cut the ends off and reused them work great now
Lots of great feedback on this. Thanks everyone.
I still would like to know why there is such a thing as "auto locking hubs" if I still have to get out and lock them manually. Kinda defeats the purpose of have the auto lock option.
If the system is working properly, will I see the knob on the will hub move to the manual position?
wopr21
I still would like to know why there is such a thing as "auto locking hubs" if I still have to get out and lock them manually. Kinda defeats the purpose of have the auto lock option.
If the system is working properly, will I see the knob on the will hub move to the manual position?
wopr21
So I guess if I'm going to need real 4WD , I'll need to plan ahead and lock the wheels manually. True?
wopr21
wopr21
Yep :thumb: always better to plan ahead.
sucks having to get out in the mud and whatever else to lock them in
sucks having to get out in the mud and whatever else to lock them in
Incorrect. If your auto hub system is properly working, the hubs will lock.So I guess if I'm going to need real 4WD , I'll need to plan ahead and lock the wheels manually. True?
wopr21
If you have an open differential in the axle, power will go to the wheel that has the least traction. If you have a Limited Slip differential, power will go to both wheels until forces overcome the clutches in the LS differential then 1 will spin. If you have a "locker" in the axle, it will lock both axles together like a solid rod between the wheels and both wheels will turn. (OK, they can unlock when needed in a mechanical and when you turn them off in the case of an air or electric locker). None of that has anything to do with the hub locks (manual or auto)
to have true 4wd where all wheels get power, you need lockers or solid axle front and rear... but that's not very friendly on the street. That's why they have differentials... solid or locked axles cause both tires to spin the same speed on that axle and that's bad in turns because you need the outside tire to rotate faster than the inside or the wheel will slip on the inside (the chirp from an axle with a locker in a corner or sometimes a spin out). A no open or LS differential allows the tires to rotate at different speeds.
in the case of my truck, I have 2-3wd in a sense. LS in the rear that will hold both spinning to a point (1-2 wheels) and an open front differential that give me 1 more wheel with power. 3wd until the rear LS lets go and only 1 spins giving me 2wd. It's called 4wd becasue all 4 wheels can get power from the engine at times.
the reason for auto hubs.. so you don't have to get out and turn the hub lock.
why are there manual hub locks on auto hubs.. when they don't work automatically, you can get out and lock them manually and get unstuck.
Do you have to lock your hubs to be in 4WD? No, only if your auto hubs are not working or if you don't have auto hubs.
Do I get better 4x4 action or true 4wd if I manually lock my auto hubs. No (OK in some cases yes). In the case of No... If you hubs are locked, they are locked whether it's the internal auto lock working or manually.. they aren't doing anything but locking the axle to the hub. Locked is locked as long as they are not broken. In special cases, changing the direction of travel (forward to back, or back to forward) will momentarily unlock the hubs (my '97 Ford Ranger was like this). I'm not sure if our hubs work like this... if they do, then manually locking them will stop this moment of unlocking.
OK it sounds like I may have vacuum line leak because I was stuck on ice and it would just spin one front tire but when I manually locked them in either the other one got traction or something because I drove right out. Good info guys.
from what i am starting to learn also about mine is this, you can manually lock the hubs but have the switch inside the truck in 2wd then when you do need the 4wd there already locked and the 4wd will just engage, i think the word auto is a neutral setting so they spin free all the time, ie less binding and not having the front axle locked in all the time for better mpgs.... then when they are engaged there fully locked in 4wd
The vacuum system can take up to one full revolution of the tire to engage the hub. So if you get stuck in two wheel drive, then engage the vacuum 4 wheel drive switch, the hub may not be able to engage. So you would then have to get out and manually lock in the hubs.
Good info. Thanks.The vacuum system can take up to one full revolution of the tire to engage the hub. So if you get stuck in two wheel drive, then engage the vacuum 4 wheel drive switch, the hub may not be able to engage. So you would then have to get out and manually lock in the hubs.
Having been stuck and still in 2WD many times if you play around with brakes and the gas you can get them to engage. Takes a bit of practice but it works every time.Good info. Thanks.
Bryce,Yes, both hubs lock. the dash knob is just a vacuum operated way of locking the hubs to the end of the axle and also shifts the transfer case.
Locking the hubs (either with the automatic vacuum method on the dash or getting out and turning the knobs) locks your wheels/hubs to the axles. the differential is still a differential. It does not lock the 2 halves of the axle together. The wheel with the least amount of traction will get the most power in an open differential type set up.
Excellent post. Just what I was looking for and the reason for joining. As a follow-up, I found the below:
Is your 4WD ESOF (electric shift on the fly) not working? Chances are the hoses to your vacuum operated hubs are dry rotted or the steel fittings at the hubs are rusted and leaking. DIESELSITE 4WD ESOF hose kits will replace the fittings and rubber vacuum hoses. These hoses are a stainless braided upgrade to your OEM hoses.
These upgraded hoses are made from Teflon lined, stainless steel braided lines. Your purchase will include both the driver and the passenger side hoses. Manufactured to fit 1999-2004 Ford Superduty 5.4L / V10 / 7.3L - F250, F350
from
http://www.dieselsite.com/1999-2004f250f350dieselsite4wdesofhosekit.aspx
Just bought a pair after 2 hours of swearing at my F250 PSD 7.3L stuck in the Ohio mud yesterday while I watched my left rear spin and other Uniroyal 285/75/R16s just laughed as I switched manual locks and the "magic 4x4 button" waiting for my daughter to come get me with the Suburban 1500.
:tard:
Great post
Great post Thanks.
I'm ordering those today.
wopr21
Great post Thanks.
I'm ordering those today.
wopr21
Which way?
I have a question.
I have never had to use my manual locks until last weekend (I have owned the truck only a year and a half). My last truck (Dodge) did not have manual hubs.
The problem is there are no markings on the hubs to indicate which way to turn them. I turned them both to the right to engage and both to the left to disengage. Does that sound right?
They were very hard to turn. Do they need some type of maintenance? I imagine there is some crud in there that needs cleaning out?
I know this is a rookie question, but it's my first Ford 4X.:icon_ford:
I have a question.
I have never had to use my manual locks until last weekend (I have owned the truck only a year and a half). My last truck (Dodge) did not have manual hubs.
The problem is there are no markings on the hubs to indicate which way to turn them. I turned them both to the right to engage and both to the left to disengage. Does that sound right?
They were very hard to turn. Do they need some type of maintenance? I imagine there is some crud in there that needs cleaning out?
I know this is a rookie question, but it's my first Ford 4X.:icon_ford:
1 - 20 of 25 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Ford Powerstroke Diesel Forum
A forum community dedicated to Ford F-series owners and enthusiasts with a Power Stroke diesel engine. Come join the discussion about performance, bulletproofing, modifications, classifieds, troubleshooting, maintenance, and more!
Full Forum Listing
Recommended Communities
