problem with neu end cover

[tc3_racer_001]

hey guys, just wanting a quick question answered in regards to the neu rear motor cover.

i ordered a 1512 2d S from castle, arrived yesterday. its a new version with 4 hex screws in the end, and i have the updated motor cover.

BUT

on the motor there are 3 wires poking out and on them there is a bit of clear plastic, then there is thick black plastic. the motor cover gets on until it hits the black rubbery thing. (obviously protection for the wires)
so i figure i have to force it on and it will be held by the rubber, but just wanted to make sure. it seems as if the cover is too big and would just slide off if these grommets or what not were not there.

so guys help me!

ryan