If you mean the 2 pc passenger side axle shaft on the D30, you can home-brew your own using a couple of different things. I used about 10 washers inside the CAD to shim the shift fork over holding the locking collar in place. Others have used a small hose clamp, and some have just slid the collar/fork over and capped off the vac fittings, and it seems to stay in place. You won’t hurt anything by doing this, and if anything it’s an improvement since you’re eliminating a potential problem area (the CAD motor, vac lines, loss of vac, etc….)
HTH,
Jeff