I too have what I believed to be a starter contact issue. My 2006 V6 4.0L Sport developed a longer than normal time to disengage after starting, only occurring when the temp would drop to around 35, and had a 'ZZZT" sound for a few seconds after starting. (In the old days we would refer to it as the Bendix not releasing.) I thought it might have been worn contacts or plunger per other posts in the forum. Bought the contact kit above and replaced them and the plunger with the same issue continuing at even a few degrees warmer than before.

I've also replaced the starter and the starter relay, with neither fixing the problem.
I'm hoping to find out what is causing this and getting it fixed before it ruins the new starter, wiring or battery by causing something to overheat or burn up from sticking.

Any help is appreciated, thanks much!! Dave