I've read a lot of post about the converter being the culprit causing the shuddering problem. Many of you have described the problem as "shuddering" caused by the converter. It sure seem like tranny slippage to me. I purchased a new Colorado Jan 1st, 2019 i began having this shuddering/slippage problem at 2131 mile. I thought maybe it will pass, could be a break-in issue. Everyday i pull out of my driveway reach the street and begin to accelerate to about 25 mph. Feels like tranny slips out of gear for a few seconds and then runs fine. At 4145 mile I take it to the dealer explain the issue they claim they can't duplicate the problem. The problem persist everyday like clockwork but then it start happening on the road slipping in and out of gear for a second. I take it in at 9059 miles I said don't give it back until its fixed they keep it 3 days, i pick up my truck ask were you able to duplicate the issue? Yes, the service mgr says and we fixed the problem. I asked what the issue was he could not elaborate, the next morning same thing. At this point I decide to begin documenting every occurrence & repair attempt. I'm over 15,000 miles and now 5 additional failed repair trips to the dealer. There's no recall yet and i am convinced GM knew about this problem for some time. I'll fight this thing to an arbitration remedy since I don't see an alternative solution. It's just unfortunate you pay good $$ for a new vehicle only to have mechanical problems from the beginning and the dealer pretends the problem doesn't exist. I've bought 4 new american cars/trucks the last 15 years each has made me wish I had purchased toyota.