2008 Commander Limited 5.7 QT2
nothing for nothing, but the NAG1 has to be filled professionally (its based on temperature since there is no "dipstick" and one has to be purchased separately) so if a dealer did the flush you're good. Otherwise - Transmission fluid filling increments.....Hoping for a little help from anyone. I have a NAG1 transmission that shifts fine in every aspect, except when it goes from 1st to 2nd. When it shifts it slams really hard. It almost feels like being rear-ended. Any ideas out there?