Help tranny/converter issues
So I got a yank 3600 converter and 373 gears intalled..car was running good so one night I got on the converter to 2500 rpm and went up like 60 foot as I was comming to a stop I felt a clunk and tempetures got pretty high check engine light came on..so I was at a dead stop and as I pressed the gas to go rpms went pretty high and car barely moved so finally car moved and as it goes I felt clunks and rpms just free reving..took car back in and got a new transmission built level 4 or 5 can't remember..got the car back running great put 300 miles on new tranny did a couple test passes and ran great tempatures on tranny stayed cool.. As I did the test passes and just now I was getting the car ready to go to the track and I was making sure everything is fine I got on the converter to 2500 rpm went up a couple feet and it started doing the same thing..tranny temps got high and I press gas to go rpms go up to 4k and car barely moves then finnally gets going and I fel same clunks and rpms free reving..what can it be ..we thought it was the trans so got abuilt one..can it be the converter? Thanks alot

