Tranny jumps out with a bang. 86-528E

Hello all. This is my 1st post.

I recently bought a 86 528E. The speedo says 300k and is stopped. Ha

The car was shifting OK when I bought it. The shifter was very very loose. I installed new front and rear metal console mounts. The car now jumps out of 1st gear with a bang. I can make it stick in 1st gear if I fuss, baby it and let clutch out slowly. Gear oil has been changed. I had a German mechanic put the car up on his lift. He adjusted it and same problem .......... Any ideas, is it still a adjustment issue or serious tranny problem.

Thanks for looking.


JJT