BW4411 Transfer Case Confusion

[wildbill23c]

According to research my 2008 Ford Explorer 4.6L V8 has the BW4411 transfer case. ADSM08 mentioned in another post that the transfer case only uses a magnetic clutch in 4Auto, but uses the typical sliding collar for high and low range. However, after reading online it seems the magnetic clutch controls everything, so who is correct? I'd lean towards ADSM08's explanation but how does this thing work? All I've ever had was manual transfer cases, you pull a lever its in high or low range, except on my Jeep which had Selec-Trac which gave me 2wd, full time, plus high and low but still with a lever and all mechanically operated.

I've played around with the 4WD Auto a bit and its almost an instant very smooth engagement. High and Low feel normal to me for a part time system but are they really mechanically linked in high and low or is that clutch actually the connection between the front and rear axles, and if so how reliable is this?

 

[wildbill23c]

Anyone tear one of these apart to know if its 100% clutch based or if its mechanically operated via a shift collar when in high and low range? I cannot find anything online that gives a definite answer.

 

[pjtoledo]

try this. it should add to your confusion.

BW4411, Borg Warner 4411, 4411 Transfercase, 4411 transfer case, omega transfercase, monster transfercase, ford transfercase

this one should push you over the edge.
looking at the parts it appears the shift motor does hi/low range and the clutch does front drive/not drive.

I'm by no means a transfer case expert, I just happened to find these nice pictures.
I'll let the experts chime in about the clutch, which appears to engage with a coil, or some balls riding in tapered slots. (think sprag)

https://www.mdwparts.com/documents/MG_TRANS_CAT.pdf

 

[wildbill23c]

try this. it should add to your confusion.

BW4411, Borg Warner 4411, 4411 Transfercase, 4411 transfer case, omega transfercase, monster transfercase, ford transfercase

this one should push you over the edge.
looking at the parts it appears the shift motor does hi/low range and the clutch does front drive/not drive.

I'm by no means a transfer case expert, I just happened to find these nice pictures.
I'll let the experts chime in about the clutch, which appears to engage with a coil, or some balls riding in tapered slots. (think sprag)

https://www.mdwparts.com/documents/MG_TRANS_CAT.pdf

Like I mentioned ADSM08 said high and low was mechanical, those diagrams just confirmed what he already said so that's what I was wondering about. Thank you.

I'm happy to know its more mechanical than I thought it was, the auto is the only electronic part other than the shift motor so that's what I was mostly concerned about. I didn't know how well it would work if it relied on just a clutch pack for high and low range, but it has nothing to do with the high and low range just the auto mode like ADSM08 said.

Now if it would just snow so I can see how well the auto mode works. Just what I could sense in the dirt in the driveway that its a very fast reacting system and very smooth.

 

[pjtoledo]

forgot to mention, page 231 in the Motive Gear catalog.

I don't think there is a clutch pack like in a differential. rather an electric clutch that works more on-off like an AC clutch.
on the auto part, there are balls that ride in tapered channels. look at the parts in the Monster listing.
when the front shaft rotates differently than the rear the balls move to the narrow part of the channel and "jam" the clutch.
I still don't claim to be an expert, that's just what I take from the parts diagrams and years of working on mechanical stuff.

 

[snoranger]

forgot to mention, page 231 in the Motive Gear catalog.

I don't think there is a clutch pack like in a differential. rather an electric clutch that works more on-off like an AC clutch.
on the auto part, there are balls that ride in tapered channels. look at the parts in the Monster listing.
when the front shaft rotates differently than the rear the balls move to the narrow part of the channel and "jam" the clutch.
I still don't claim to be an expert, that's just what I take from the parts diagrams and years of working on mechanical stuff.

Without opening any links or reading anything...
that’s exactly how the bw4405 (used in the Explorer before the 4411) engaged A4wd. Makes sense they would stick with something that was already proven to work good.

 

[wildbill23c]

Given the 4auto has a variable amount of power that it can send up front, I'd think the electromagnet just engages the clutch and the ball ramp is what actually moves the power up front depending on the speed difference front to rear as to how long that electromagnet stays engaged I assume. Seems like very little information out there as to how it actually works for some reason. Does seem to work very fast though in the little bit of testing I tried in my driveway in the dirt.