BW4405 Rebuild: Clutch Pack (disc) Orientation

[JamesB]

Hi all,

I am rebuilding my 4405 and pulled the clutch pack out to inspect for abnormal wear or overheating. In the process, I forgot to place the clutch disks in such a way as to remember their orientation.

My question is this: what is the orientation of disk placement in the clutch carrier housing (7C108)? Do the clutch pads face out of the housing (A: wearing pads facing towards you when you place them) or do the pads face into the housing (B: wearing pads facing away, or down into the housing)?

ie: A: [__] pads facing ^^ (how I believe it goes)
or: B: [__] pads facing vv

Thanks for your help guys! I have lots of pictures of the rebuild in progress and plan to do a "photo-writeup" on the process - including all those tricky bits like the hidden snap-ring required to remove the input shaft (7017) which is required to remove the planetary gear set.

 

[je5]

Facing you. Such that when trying to remove them you have to be careful to not ##### up some of the friction material.

 

[IZwack]

The clutch pack can only be placed one way - there are small little notches that must be lined up. Flip the clutch pack upside down and the notches wont line up.

Below is a picture showing one of the tabs that the notches must line up with

 

[JamesB]

Thanks guys!

I I didnt even consider that the notches would prevent the clutch pack from facing the wrong way. I really should have caught that.

-James-

 

[Wrench]

pic of clutch assembly

IZwack - do you have an exploded view of the 4405 TC clutch assembly.
I curious how it looks and works.

 

[IZwack]

IZwack - do you have an exploded view of the 4405 TC clutch assembly.
I curious how it looks and works.

Hehe sorry I have plenty of assembled images and what not but I don't have any exploded view.

But to sum it up, basically you have a stack of friction plates. Normally, there is of course not that much pressure against these friction plates. When the electromagnet is energized, it pulls on a ring/disc which causes 3 metal balls to travel up a small ramp - whch pushed down on another disc directly in front of the friction plates. This puts the vehicle in 4wd mode. Note that it is actually the rotatation of the input shaft that provides the energy to lock the front axles. By itself, the electromagnet does not squeeze the friction plates - the rotation of the input shaft is what squezes them together.

I will post what pictures I have soon.

BTW too bad - I just threw away a 4405 last week! I could have done the exploded diagram - darnit.

 

[IZwack]

IZwack - do you have an exploded view of the 4405 TC clutch assembly.

Ok here's an exploded diagram of the entire 4405 transfer case:

 

[IZwack]

Okay I felt bad that that exploded diagram was too tiny so I modelled up the clutch assembly. I tried to use the same names as the ones Ford uses.

It's not too detailed so don't complain if there are two splines are missing on a part

\

 

[Wrench]

4405 t-case pic's

Thx's for taking the time to post the pic's
From looking at the diagrams the coil is energized to cause the cam to apply force against the clutch pack which inturn tranfers motion to the front driveshaft. A certain amount of slip is incured in the clutch unit when applying torque to the front drive unit in the auto setting depending on the amount of slip detected by the sensors between the rear and front driveshaft speed sensors. When no slip is detected then the clutch pack fiber disks spin freely between the steel discs due to the chain drive turning the whole unit all the time the rear drive shaft is rotating.
I certainly could see why these units fry due to an overheat condition if you were in slippery conditions and required the unit to work hard, the case only hold 1.5L of oil and no means of cooling.

 

[joe-doggs]

How the electromagnet gets it tremendous power

THe three balls are called a "self-energizing" ball ramp actuator - the electromagnet initiates the balls climbing the ramp - as the assembly rotates - the balls keep climbing & applying pressure - IE the magnet force is not what holds the clutch pack - they initiate the small force for which actuates the balls - which apply a tighter force as the assembly rotates .. Boeing has these all over there mechanical systems in the anti-backdrive portion of their flap and slat drive systems .. very clever little mechanism ..

 

[Worldwide Fords]

Ok here's an exploded diagram of the entire 4405 transfer case:

Does anyone have the part names that match the numbers please ?

 

[IZwack]

Don't have the part numbers but if you are specifically looking for the clutch pack (which I'm assuming as that is what this thread is about), then here are some sources:

http://transpartswarehouse.com/inde...03-ford-bw4405-transfer-case-clutch-pack.html

http://www.ebay.com/itm/Ford-BorgWarner-BW4405-4405-Transfer-Case-Clutch-Pack-/370481015449

http://www.ebay.com/itm/TRANSFER-CA...05-Frictions-Steels-BORG-WARNER-/270922842482

 

[Worldwide Fords]

Don't have the part numbers but if you are specifically looking for the clutch pack (which I'm assuming as that is what this thread is about), then here are some sources:

http://transpartswarehouse.com/inde...03-ford-bw4405-transfer-case-clutch-pack.html

http://www.ebay.com/itm/Ford-BorgWarner-BW4405-4405-Transfer-Case-Clutch-Pack-/370481015449

http://www.ebay.com/itm/TRANSFER-CA...05-Frictions-Steels-BORG-WARNER-/270922842482

Its not the clutch packs I think, when I drive its fine then all of a sudden there is a noise like spinning sound, when you back off on the pedal, you put on the power again, it goes, someone said its the transfer case problem ??.

 

[IZwack]

Could be a few things - but from what you've posted, another part of the vehicle that can exhibit that behavior / noise is the rear axle. To be more specific, if the rear axle's pinion gear is loose, it wobbles a little bit and this, along with improper gear engagement, will cause a noise as you back off of the gas pedal. One way you can determine if it's the pinion that's causing the noise is to disconnect the rear driveshaft from the rear axle's input flange (takes a 12-mm, 12-point socket) and move the pinion flange up/down and side/side - if there's any lateral play, then the culprit is the pinion bearing. But do a search for this as it's been covered many many times on this forum.

 

[Worldwide Fords]

thanks ok, will check it all out, thanks for the advice

 

[KPT]

Its not the clutch packs I think, when I drive its fine then all of a sudden there is a noise like spinning sound, when you back off on the pedal, you put on the power again, it goes, someone said its the transfer case problem ??.

It sounds like you have the worn shift rail bore problem.