2nd Gen Non-Engine/Transmission Unlocking front axle vs. full time axle

[Kernel]

Does anybody know why some '02's have unlocking front axles and others have a full time axle. A friend of mine has an '02 (built Feb '02) and has a full time axle and has noticed others with the old style unlocking vacuum assisted disconnect. Did a search couldn't find anything on it. Any help guys?



Scott

 

[nps]

They discontinued the CAD (center axle disconnect) in the middle of the 2002 model year. If a 2002 has it, then the truck was an earlier build in the model year.



I speculate it is because of the switch to american axle and the CAD axle was a DC special. So when they ran out, DC used standard Dana 60s without the CAD to complete the model year build.

 

[Kernel]

Thanks for the reply. Any idea if a conversion is possible or available?



Scott

 

[nps]

You could do a swap of the front axle.



The CAD setup actually cuts the axle tube and puts the disconnect collar and associated housing/linkage about halfway between the pumpkin and the passenger wheel. So reworking a non-CAD axle is not practical.



If you do swap axles, also needed is a vacuum switch that goes in the top of the transfer case, and the vacuum lines that connect the switch to the CAD actuator.



Alternately, you can put a cable in place of the vacuum switch/motor setup for more positive control. This is the approach I would take if doing a swap. You'd also get the ability to run in 2WD Lo with a cable - a good feature for backing up a heavy trailer.



With a disconnected axle, you still spin the wheel u-joints, axles and side gears inside the diff. But the driveshaft and ring/pinion gears don't spin unless the axle is engaged.



Bottom line - IMO if you don't want 2wd Lo, swapping the axles is not worth the gains.

 

[Fishin Guide]

I agree, it would be hard to justify the swap. Maybe a wrecking yard would be the best source of a CAD axle and the related parts.



The only reason I can see to go through the expense and headace is if the truck was lifted to the point that the driveline was giving you fits. Fuel milage gains are most likely minimal.



If it's a 2 low situation that you are looking for, I would grin and bear it.



Dave

 

[Kernel]

The friend of mine doesn't like the mileage his 24 valve gets compared to all the 12 valves he has/had in the past and doesn't know why they would switch something somewhat good mid-model year. We both wondered if it was because of the then up coming change with the 03's. Thanks for the help guys.



Scott

 

[fox]

I doubt the CAD swap would change the mileage any thing noticable.

 

[JKinney]

What is this cad I have an 02 is the cad that sleeve that is on the axel on the left hand side looking under the truck from the front? And what does it do?

 

[fox]

CAD is central axle disconnect.