Help with 4x4 auto

[07navi]

Both

There is zero chance that the front wheel drive is just slammed together with one side stationary and the other side spinning at high rpm like someone said.
For an actual description.... Read patent US5105902A

Both axles from the diff spin when you select 4 auto and the IWE is like a sliding dog in a motorcycle trans which does slam together. Neither have any synchros in them.

 

[JExpedition07]

There is zero chance that the front wheel drive is just slammed together with one side stationary and the other side spinning at high rpm like someone said.
For an actual description.... Read patent US5105902A

Nobody said anything was stationary. Your hub actuator is spinning with the wheel 100% of the time and the CV axle starts to spin when you shift to 4H. The vacuum is then released and the splines on the actuator mesh up with the CV axle splines as the diaphragm releases it to the axle shaft. The faster you are going the more wear is going to occur when this event happens, because the actuator teeth are soft and sacrificial, and any slight variation besides dead straight varies your front wheel RPM. I’m not going to read through a patent, but I’m pretty certain this is how it works based on my dissection of my old actuators.

 

[Plati]

Nobody said anything was stationary. Your hub actuator is spinning with the wheel 100% of the time and the CV axle starts to spin when you shift to 4H. The vacuum is then released and the splines on the actuator mesh up with the CV axle splines as the diaphragm releases it to the axle shaft. The faster you are going the more wear is going to occur when this event happens, because the actuator teeth are soft and sacrificial, and any slight variation besides dead straight varies your front wheel RPM. I’m not going to read through a patent, but I’m pretty certain this is how it works based on my dissection of my old actuators.

Hard to understand what people mean to say with their typing. I read vincentrose post to mean that differential not turning in 2H and I think he may be right. But after you shift to 4A it will start spinning and synch with rear rpm then engage front actuators. It would never exactly match in front so I can see how some damage could happen.

patents arent bad. I studied about 10,000 if them over 15 years and if you want to know exactly how something works ... thats the ticket

 

[07navi]

That patent from stickler is not for the torque on demand Borg Warner control trac so it means nothing. Again the IWE is merely a dog type connector like motorcycle transmissions have which do "clash" together since there are no synchronizers. As for the IWE being soft and sacrificial I think it is more like they take all the punishment which is good since they are 3 times easier to replace than the Superduty hub actuator and they do well considering the job they have.

 

[Plati]

That patent from stickler is not for the torque on demand Borg Warner control trac so it means nothing. Again the IWE is merely a dog type connector like motorcycle transmissions have which do "clash" together since there are no synchronizers. As for the IWE being soft and sacrificial I think it is more like they take all the punishment which is good since they are 3 times easier to replace than the inside of the Superduty hubs and do well considering the job they have.

Wrong again Batman. You trying to set a record for being wrong? Breaking your own record is pointless? Lol

 

[Thunderbirdsport]

Both

Both axles from the diff spin when you select 4 auto and the IWE is like a sliding dog in a motorcycle trans which does slam together. Neither have any synchros in them.

In a stock Expedition/Navi, no, they do not both spin.*

With a locker/Limited slip, they will, so aside from those so-equipped trucks....

Show me where in the owner's manual it says to NOT engage 4A at any speed. Only while stopped.

Because I looked in mine...it ain't there.


*unless the vehicle is actually going down the road, which is obvious because of the direct connection to the wheel/tire via the IWE.


Not sure what you're trying to argue here. That Ford put a system in that CAN be used in 4A, but also doesn't have to be, but those who use it in 4A on dry surfaces are wrong because you personally don't? Hmmm.

A better argument would be if it was known that putting the selector in AWD while at speed causes it to "slam" the driveline when the front "kicks in", or does it engage slowly s as not to "shock" the front driveline? You yourself have worked on drivelines, so, which is it?

 

[07navi]

The front axles.

 

[JExpedition07]

Hard to understand what people mean to say with their typing. I read vincentrose post to mean that differential not turning in 2H and I think he may be right. But after you shift to 4A it will start spinning and synch with rear rpm then engage front actuators. It would never exactly match in front so I can see how some damage could happen.

patents arent bad. I studied about 10,000 if them over 15 years and if you want to know exactly how something works ... thats the ticket

I don’t see his posts anymore unless I press the little button now I see what I missed. My bad.

 

[07navi]

Front diff is not turning in 4 hi but turns when you select 4 auto, then all axles coming from both diffs are synched, then the IWE (strange name) locks the front diff to the front wheels and the front drive is now ready for the computer to control it's usage.

As for blocking people; it reminds me of the ostrich.

 

[Plati]

Front diff is not turning in 4 hi but turns when you select 4 auto, then all axles coming from both diffs are synched, then the IWE (strange name) locks the front diff to the front wheels and the front drive is now ready for the computer to control it's usage.

As for blocking people; it reminds me of the ostrich.

Front differential is not turning in 4 hi???????
Huh?

 

[07navi]

Right, not turning.

 

[Plati]

Right, not turning.

Oh I see, you are your own lexicographer.
You decided what the word "turns" means.
You have your own personal only known to you definition of that.
Since it doesn't do whatever "turns" means to you .... must not "turn"

 

[mnachreiner86]

You guys remember that episode of Friends where Chandler tells Joey he’s not allowed to talk to people anymore because of the stuff he says? This is turning into that...


Sent from my iPhone using Tapatalk

 

[07navi]

W

Oh I see, you are your own lexicographer.
You decided what the word "turns" means.
You have your own personal only known to you definition of that.
Since it doesn't do whatever "turns" means to you .... must not "turn"

Whaaat??????????

 

[Thunderbirdsport]

Comedy gold, here.

I think that since we're on an automotive type of forum, that when we use the word "turn", especially in context with an object or objects, that, well, generally rotate, or "turn", if you will, that saying that a rotating part does NOT turn when directly activated and mechanically linked to the rest of the driveline as opposed to turning ONLY when said activation and mechanical (or fluid-type) linkage (in 4A) in this exact instance is both wrong and misleading.



Now, I've been around 4x4 vehicles, mostly Ford and Jeep since I got my "road ticket" over 3 decades ago and have worked on, in, and under every single one of them (I did say jeep, did I not? LOL!), and regardless of t-case type, method of transferring power to the front, via chain, fluid viscosity change, or simple gears, if the vehicle is in motion, the system is in proper working order, and the selector is engaged to activate the t-case and the front driveline, then the axles and ring gear HAVE to rotate.

I have tested this myself on my own '11 Expedition trying to track down a noise. Tires (4) off the ground. In 4H, in drive, idling....guess what? front and rear both turned.

barring broken parts, this can't NOT occur.

 

[Ohio JEA]

I have 2012, heavy snow here in OH this winter, so I used the 4 Auto quite a bit. Anyway, now that it's back in 2H - I notice a strange intermittent rattle noise that lasts about 3-4 seconds then goes away. Sounds like it comes from the front left side. Usually under light acceleration, 1400-1600 RPM only. You don't hear it when under load or during quick acceleration. I have taken to mechanic 2 x and they cannot make the sound appear when they test drive. Frustrating. Ideas?

 

[Josha907]

You need it or you don't!!!!!