Engine/Transmission (1998.5 - 2002) CAD failures?

[Texas Diesel]

Has anyone had the CAD system fail? What were the conditions that lead to the failure? I'm not wanting to get into the theoretical arguments pro or con, just did it break. TIA

 

[Animal]

I did, the little graphite pieces wore out on the CAD fork. This caused the splined coupler to not mate up the two axle shafts correctly. While moving a loaded trailer in the mud the force on the coupler bent the fork shaft (motor assembly). This ended my 4wheel drive engagement and I had to be pulled out of the mud after unhooking the trailer by my buddies Ford.



Checking these graphite pieces and replacing them before they wear out can avoid this. My truck had 155,000 miles on it when it broke.

 

[Texas Diesel]

Thanks Animal but are you the only one?

 

[Hunter11]

I guess I will be the dummy here, what are we talking about? Where is it located and how can I check it?

 

[lsenus]

Count me in for the dummy count. Two heads are better than one.

 

[Texas Diesel]

Sorry,



it is the Central Axle Disconnect on the front axle of 4wd's.

It is the vacuum operated gizmo that is responsible for locking the front axle in. If it is broken, you'll know because you'll be struck.



I have a theory that that fail because they are not allowed to engage fully because of rotational torque. My idea is that you need to engage the 4wd in forward then go into reverse to allow the sliding coupler to engage the splines fully. Driveline bind would not allow the vacuum motor to do it's job. It is just a half baked idea that's why I wanted to know HOW they failed.



I'll attach a diagram of the CAD's internals.

 

[Animal]

CAD

CAD stands for "Center Axle Disconnect"; it is what connects the left and right wheels of the front axle together for 4X4 operation. It's located on the passenger’s side of the front axle.

 

[Hunter11]

Okay I've got it now. So this part that tends to break, can it be inspected from the outside or do you need to disassemble something to check it out? How hard is it to do? Thanks

 

[Animal]

You'll need to disassemble it.