Upgraded IWE

[Squatting Dog]

I know I have posted these somewhere before.. I couldn't find them..

So I will post them again..



This is your IWE...



IWE dissected



This spring is the only thing holding the locking ring engaged to the hub.. When the vacuum is released this spring pushes the ring onto the gear on the back of the hub.



This is the 1/4" locking ring. It is made out of a softer metal to prevent damage to the hub gear or axle gear. Every time the ring engages or disengages the spinning hub gear the teeth become rounded on the locking ring.

-Greg (aka Squatting Dog)

 

[Wilson]

I know I have posted these somewhere before.. I couldn't find them..

So I will post them again..



This is your IWE...



IWE dissected



This spring is the only thing holding the locking ring engaged to the hub.. When the vacuum is released this spring pushes the ring onto the gear on the back of the hub.



This is the 1/4" locking ring. It is made out of a softer metal to prevent damage to the hub gear or axle gear. Every time the ring engages or disengages the spinning hub gear the teeth become rounded on the locking ring.

-Greg (aka Squatting Dog)

and that is suppose to hold 411 hp lol

 

[Squatting Dog]

It is not the horsepower but the 434 ft/lbs of torque.. Then add the torsen with a ratio of 2.52:1 (I think) and then you are looking at close to 1100 ft/lbs! That is what tears the teeth off.

-Greg (aka Squatting Dog)

 

[phydough]

Could the computer be rigged to say "Slow to 5MPH to Shift 4x4"? Without letting it shift until under 5 MPH, you know... like going into Off Road Mode.

Pain in the ass, but Shift on the Fly shit be damned.

 

[Stepside]

1st = 4.17:1
2nd = 2.34:1
3rd = 1.52:1
4th = 1.14:1
5th = 0.86:1
6th = 0.69:1
Reverse = 3.40:1
Axle Ratio = 4.10

 

[Squatting Dog]

It would need to be more like shifting to 4 low. Even at 5 mph there is still some slipping and grinding until the locking ring fully seats on the hub gear. What normally happens is the locking ring slowly engages because of weak spring pressure. The force of bringing axles and differential up to speed causes locking ring to override/slip and chip the locking ring teeth.

Damage to the locking ring teeth have been observed on Raptors that have never used 4wd. The first time they needed it and used it the were greeted with a loud pop and clunking.
During failure analysis it was determined that even with check valves to hold vacuum during engine off conditions. There was enough vacuum leak down to cause one or both of the hubs to partially engage. The owners would start up or remote start their vehicle then drive off before enough vacuum to disengage the hubs.
This would cause the vehicle to be in 4wd with the owner being unaware. Then the IWE solenoid finally operates and sends vacuum to hubs and pulling the locking rings off the hubs causing wear without actually using 4wd

Side note. Thanks to AZengineer finally figure out why 10 minute run during remote start wouldn't build vacuum. During remote start that part of the powertrain /bcm is not on, so the IWE solenoid does not operate until the ignition is turned on.

This system flat out sucks to many points of failure.. It works great in a test lab with a hand vacuum pump. Or in a vehicle that does not have a torsen. The nature of the torsen is to bias torque to the wheel with traction at 2.52:1 multiplication. That would effectively put the torque at close to 1100 ft/lbs If the locking ring slips during engaging/disengaging, the torsen would think that wheel is slipping and transfer that torque.

-Greg (aka Squatting Dog)

 

[R1jamn]

Side note. Thanks to AZengineer finally figure out why 10 minute run during remote start wouldn't build vacuum. During remote start that part of the powertrain /bcm is not on, so the IWE solenoid does not operate until the ignition is turned on.

Thanks for this piece of info.
I use remote start often.
So basically after remote starting, I need to insert the key into the ignition then turn it to the "ON" position,
then wait a few more minutes to let the computer system wake up and pull vacuum before I place my Raptor into gear and take off.

F&@K ME!!!!

 

[Squatting Dog]

Yes.. Until there is a solution to this weak as system. A couple of minutes each day may save the IWE for the time you need 4wd the most.

-Greg (aka Squatting Dog)

 

[Wilson]

I was just thinking today what if I leave it in 4x4 and take it out on the fly if I can remember to put it in before I shut the truck off every time.

 

[Stepside]

1st = 4.17:1 x 4.10 x 434 = 7420/4 = 1855 lb.ft.
2nd = 2.34:1 x 4.10 x 434 = 4163/4 = 1041 lb.ft.
3rd = 1.52:1 x 4.10 x 434 = 2704/4 = 676 lb.ft.
4th = 1.14:1 x 4.10 x 434 = 2028/4 = 507 lb.ft.
5th = 0.86:1 x 4.10 x 434 = 1530/4 = 382 lb.ft.
6th = 0.69:1 x 4.10 x 434 = 1227/4 = 307 lb.ft.
Reverse = 3.40:1
Axle Ratio = 4.10

This would be the maximum torque delivered to each wheel
provide one was at peak torque and traveling in a straight line.
But, that is Not real world scenario, because IWE is not supposed to be engaged under that kind of torque load.
On the fly = coasting/no load.
With that being said, the design of the IWE looks like Splines on a windshield wiper arm - in my opinion - and
Not for the rotating mass it sees in its environment.
So, I think any improvement made will be a 'good thing'.
.... and thanks, Greg - for you tenacity on this subject.

I've edited the above from my previous post.