We can send you one if needed. However we have been looking into this for the last couple hours. There are a few local racers who put their cars together and a couple reported the center diffs being tight, but not locked. Others had no issues at all which is strange.

So there is a component in the diffs that is not consistent from part to part. We have narrowed it down to the big shim under the bevel gear (TKR5145 - 6x17x.3mm shim). We looked at a few of them (new) and noticed some are warped (coned up or down). Others are flatter. We then looked at the same shim from a heavily used (smooth) center diff and it was totally flat. That inconsistency in the shim is pushing the bevel gear into the diff mesh causing the irregularity.

One of the center diffs at the track was pretty tight - not smooth, but after breaking it in for 30 seconds, it made a huge difference and was waaaay smoother. The short break in time flattens the shim out and the irregularity went away. Their car is good to go and they are racing tonight .

NOTE: This seems to only affect the center diff, which makes sense as the plastic gears can distort and warp (they all do). For what it's worth, we put one of the steel spurs on one of the production center diffs and the diff felt normal.

Ironwolf, PM me your phone number (or email us at [email protected]) and we can see if we can work through a solution. We'll send out whatever parts you need to make sure the car operates as intended.

We expected to have some issues, but the diffs weren't one of them . We tested this car for almost a year but it seems the production diff parts are just a little different.

We are confident that after the center diffs are broken in and used that they will be smooth.

Let's all help each other get the information out and work together. I hope everybody knows that we are on this like flies on $#!+. If anyone else is having issues after breaking in the center diff, please let us know.

Thanks.