I’m doing my first ls swap I bought a rebuilt trans 4l60e out of an 02 Silverado to Mach my 4.8 and during install I crushed the pump (yeah I know dumb mistake but I learned) and I rebuilt the pump it was right installing the pump back in place however it did go now trans is in I have all forward gears and no reverse could I have messed somthing up with installing the pump? Should I pull it back out or leave it in and try to find the issue with it installed?

 

did you put new sealing rings on the pump stator? did you pinch one?
The reverse drum oil is delivered via the stator. Those are what the 2 rings on the pump are for.

 

To add to what MaroonMonster said, if someone replaced the front bushing in the reverse drum (one towards the pump), many times the bushing is sharp on the outer edge and fits tight around the pump rings. If left that way will slice pump rings.

Also, are you sure it's a newly rebuilt trans and not something that was only sealed up? Other things can cause no reverse.