NEEWER%C2%AE Bayonet Mount 18 105 55 200mm
This worked great on my Nikon AF-S DX 55-200mm f/4-5.6G ED. Cheap fix for a lens that would be too expensive to send to the repair shop IMO. If it ever breaks again, I am just a few dollars away from a fix.
The repair itself was easy but you do need to be careful. Check youtube for how-to videos. Be careful though since this piece will fit in multiple lenses but the repair may be slightly different depending on if they are repairing the same lense or not. This took about 10 minutes and I was going slow. I used a small philips screwdriver (you will need a very small screwdriver) and a pair of needlenose pliers. Tweezers would have worked as well.
1)Remove the five screws around the bayonet. (Screws going towards the rear lens element) Pay attention to where they were, I had two different kinds.
2)Remove the ring that is around the rear lens element. (Not the bayonet piece itself but between that and the center lens)
3)Remove the three large screws parallel with the barrel of the lens.
4)Push the piece containing the metal contacts back and work the old bayonet off carefully. It will not come all the way off. You will need to remove one screw on the bottom side which is holding a small wire and contact assembly in place. This will also release a small spring and metal piston. (When replacing, the larger end of the piston goes in to the new bayonet)
5)Remove the larger (aperture) spring from the old bayonet.
6)Reverse these steps with the new bayonet piece.
Basically, if you pay attention to how you take it apart, you just put it back together the same way.