yeah i believe it is the 2 piece shaft. Mine was doing the same until I put in a 1 piece aluminum with real man joints. also when i replaced my clutch and fly wheel and put it all back together i guess i forgot to put locktight on the bolt that secures th tranny to the cross member and it eventually shook itself loose and out then it made a whole lot more movement. oops, but now the problem is solved. You should be fine though.