904 shifting problem.

no first gear issue as well? Like I can’t get it into first.? Feels like it starts off in second?I do have reverse but it engages hard
This says your pump is good, the hi-drum is good and the L/R band is working.
It is impossible for this trans to start in second, unless the VB is messed up, and that is not likely. More likely is that the Clutches in the hi-drum are piled up, or nearly so, and now when you put it in Manual low, the trans is in two gears at once. If the vehicle moves at all, then the Band is winning,lol.
That's my guess.
Smell the dipstick; any stink at all, and there's your proof.
If the fluid is off-color or stinks or has any black powder on the dipstick, then I bet I'm right.
That trans is super easy to rebuild. You just need three tools; a circlip plier, a hi-drum spring compressor,and a bumping tool to pull the frontend out.
The bumping tool you can get around without.
The compressor you can rig up
That just leaves the plier.
The repair parts are about 200/250 for everything you need.