Guver, Sorry about missing all those posts by you! Ok time to try and answer questions.
- The only shims that I know for the diffs are in this kit
http://www2.towerhobbies.com/cgi-bin...?&I=LXTB43&P=M
- rear steering on 2 channels is possible but you have to buy a Y harness. One end plugs into your receiver then the two other ends plug into your servos. A couple problems here. Instead of only one servo pulling power you now have two. Some BECs on speed controls won't like that much and you might have to run a receiver battery pack (adding weight). The other problem is most 2.2 classes don't allow rear steer. We don't care at our get togethers though. 4 wheel steering will be better for turning than just front steering. Simple. It might result in having to buy other electronics though and you might be better off just getting a different radio and running independent rear steer (TQ3 radios are about 20 bucks used and you can mod the switch yourself) You're right, locking the front and rear starts to really hinder steering when you run the stock style linkages. Your best bet is to mount the servo on the axle. There is way to much slop in the linkages when the servo is mounted on the chassis.
- Gearing, I'm running a 13t pinion and a 66t traxxas spur. The stock WK gearing is pretty tall and will stall motors out pretty easily. I run a 65t axiom also but I'm running it at 8.4v.
- If you are asking about the small stamped steel axle mounts I am using they are tamiya parts and are out of stock right now. If you are talking about the plate aluminum on the axle. I made those.
- There a lot of ways to setup the links. The easiest thing to do in my opinion is go out and buy some 6-32 all thread from lowe's or home depot. Cut that into the lengths you think you need and put your rod ends on them. Hook it up to your truck and see how they work out. If it doesn't work then take the links off and shorten them up. If you need longer links then save the shorter piece for future mock ups and cut a new one.
Here is a picture of the all thread with rod ends on my truck when I was mocking the links up.
