I have a 2001 (2nd gen. Cummins) 2500 4x4 SRW with the CAD system on the front Axle and needed a few questions answered. 1st post BTW and just joined.....

The PO has disconnected the switch for the 4x4 at the CAD (the connector that plugs into the CAD). The switch/sender is still connected to the CAD but there is no connector anywhere NEAR this. I've looked up and down and it just is not there, so my question is, where does the connector plug into that runs to the CAD (i.e. as in where on WHICH wiring harness is it Tee-d off of)? Can a replacement be ordered and then just plug into the wiring harness on one end and the CAD switch on the other? Any pics showing both ends would be VERY helpful.

BDK

I like that plan.

I think I remember seeing some stuff on Ebay when I was researching my jeep. I decided that since Chrysler went ay from the vacumn actuator that I'd bust out the welder and do the same.

 

Jeep light comes on and says part time 4wd.

 

My truck 4x4 light comes on half th time.  Not sure why  though it doesn't matter

Yep, the perm-lok seems the way to go as long as there's no issue with having it permanently locked (mileage may decrease a bit from what I've read but no biggie).

 

BDK

11 minutes ago, BDK said:

Yep, the perm-lok seems the way to go as long as there's no issue with having it permanently locked (mileage may decrease a bit from what I've read but no biggie).

 

BDK

No there is no loss to perma-locked axle. When my high mark on the diesel is 27.2 MPG. Typically doing 19 to 20 MPG.

Cool, that's my ticket then...

Hence why CAD axle design has been obsoleted and no longer used. All future trucks are all solid axle design now. 

13 hours ago, Mopar1973Man said:

Hence why CAD axle design has been obsoleted and no longer used. All future trucks are all solid axle design now. 

Nope. 
 

CAD came back in 2013. 

 

It’s reported it came back for a ~1 mpg raise. 

 

Not sure I buy it. When I went with hubs on my 05 I didn’t see any increase. 
 

I'm not a huge CAD fan, and prefer how ford does their hubs. 

Edited February 4, 20205 yr by AH64ID

Haven't seen it yet... most likely will some time.

23 hours ago, Mopar1973Man said:

Another rare one is be climbing a grade but the manifold vacuum is low and have it unlock the axles when you least expect it and really need the 4WD.

 

I don't think this is a normal condition (I know you said rare) unless something else isn't right. If you disconnect the vacuum lines when the CAD is engaged, shouldn't the CAD stay engaged? Doesn't the vacuum circuit have to reverse and apply in the opposite direction to disengage it? Have you replaced the vacuum switch on the transfer case?

Zim,

 

If your check valve is bad, loss of vacuum to the actuator would allow it to release.  It is sort of spring loaded to "open" or go to 2 wd.  (plus the loading will tend to spit it out also)  To stay in 4wd, I have to lock my cable.  To get out of 4wd, all i have to do is release the lock.  Within a minute or two (couple stop and goes etc) the coupler will spit itself out of 4wd. 

 

So constant vacuum "on" or "off" is preferred.

 

Hag

Well you guys talked me into it. I ordered a Posi Lock. Now if I could only get that axle tube to stop leaking.  ?

Edited February 4, 20205 yr by Threadzy

Dad ran posi loks on a 92 K2500 and then a 97 2500 suburban. We bought the kit for the 92 at the sportsman’s show in Seattle from the original designer/owner. 
 

Great products. 

Edited February 4, 20205 yr by AH64ID

3 hours ago, Haggar said:

Zim,

 

If your check valve is bad, loss of vacuum to the actuator would allow it to release.  It is sort of spring loaded to "open" or go to 2 wd.  (plus the loading will tend to spit it out also)  To stay in 4wd, I have to lock my cable.  To get out of 4wd, all i have to do is release the lock.  Within a minute or two (couple stop and goes etc) the coupler will spit itself out of 4wd. 

 

So constant vacuum "on" or "off" is preferred.

 

Hag

 

Excellent information, thank you.