Hi, i have 2002 blazer 4x4 automatic with the 4 buttons on the dash that clunks sometimes in first. It sometimes does it when i take off with about half throttle or more.. the more throttle the harder the clunk. when it clunks the rpms seem to jump abt 2 to 4 hundred rpm and will jolt forward and sometimes even chirp the tires if i give it heavy throttle (tires are nowhere near bald), it does this in 2wd hi, 4wd hi and auto 4wd and only from a complete stop.. haven't tried 4wd low. It seems to always do it around the same rpm and only in first Checked the tranny fluid, it seems fine and smells fine. its def not a 1-2 shift, if anything it feels like a hard 2-1 downshift, however i've tried switching the gear selector to 1 and taking off and it still does it. it happens around 2000-2200 rpm... If it matters, all shifts are smooth,

Also probably unrelated, when in 4wd mode there is a whine from the front that gets higher pitched with speed

Thanks in advance for any info.