Thread: shifts 2nd to 4th with no 3rd

hey guys I've been having trouble with my trans of late. my trans will not shift into 3rd gear it goes straight from 2nd until about 45/50 mph then shifts into OD. Ive read some some later posts that this means that my tranny is shot now which I'm really hoping isnt true. the mods i have in this thing are a chrome moly pump shaft, 3.29 gear, transgo shift kit, and aluminum pan. the trans is out of a 04 impala ls but with all the hd parts. Can someone walk me through on what is join on with this trans? also my 1-2 shift bangs hard and even makes the wheels chirp. other than the tranny not having 3rd and that harsh 1-2 shift the trans works nice.

the car is on 04 impala ls but i did an l32 swap with an xp cam, n* tb, lq4 maf, zzp headers, and it was just all dyno tuned with all the correct info. i did a 3.29 gear change and all as well.

how is the trans join like what parts fail with this situation? i don't think the whole trans is junk just because I'm missing 3rd now i would think that something is wrong with 3rd or something not alloying me to shift to 3rd.