Auto transmission judders when changing gear when hot

[328s_rock]

Hi, hope someone can help..

I have a '95 328 with 5 speed auto transmission.. Done about 108,000 miles.

Recently on a long journey noticed that the gear change from 4th to 3rd was very 'fierce'. Jerky rather than smooth.

I dont know how to describe better, but all changes are usually very smooth, except for this occasion.

It happened several times every time changing down, but has not happened since. I can only guess this was after a fairly long journey with everything hot. I have not noticed anything unusual on recent short trips.

Any help/advice appreciated.