I've been playing around with the car a bit more to try to find the reason(s) behind the inconsistent centering, as well add trying to remove more play from the steering. The kimbrough servo saver fits very loosely on the splines. ... I'm sure this would cause some/all of the problem. Too bad, cause the servo saver seems to function decently. ...firm, but not too firm.
I removed the 0.2mm shims from the steering and replaced them with 0.3mm ones which helped a bit, but there is still a lot of play in the smaller 3mm ID bearings.
I used the"plastic bag" method of taking up play in a couple ball cups, and swapped out the servo saver for a plastic servo arm that was supplied with the kit. The servo am is a tiny bit longer, so gives a bit more steering throw, which my car needed.
I'd like to try the inner holes on the steering blocks, but it results in the tie rods hitting the sway bar links....grrrr. That is a bit of a design oversight methinks.
a sloppy server saver will definitely cause issues... its a shame hobbyking doesn't give you the spline count - that would definitely tell you who's server you'd need.
you
could always be brave and count them yourself
once you get a count, you can tell while brand (futaba, airtronics, hitec) you'd need
if the kimborough saver you have has the inserts - just try each until it fits very snug. once you get that, there's the one you'd need