grinding when moving ###zz help

[wreckshop56]

Hey guys need your help
Just got my car back from the shop..Rebuilt Head and Shortblock new clutch also..
well when he took my engine apart he told me my trans needed to be rebuilt because i had a rattle noise at first before i took it to the shop...well i gave him another trans that i bought..he put it on...so i get my dad to pickup the car from the shop and he said it feels like its grinding...so i get in and take it up the street and 1st gear it grinds when accelerating...i dont think its supension because when i put it in neutral its fine..it also pops into gear sort of if i come off the clutch smooth then its fine..i just want to know what could the grinding noise could be and am i messing up anything...The way i see it...New Engine..New Clutch...Used Transmission

thanks

 

[BISHILVR]

Old/bad tranny and motor mounts can cause the problem, also cable adjustment problems can make it jump out of gear.

 

[wreckshop56]

well gear poping is fixed i just need to adjust..the grinding noise when moving in 1st 2nd n 3rd is still there