Tranny Problems

[Alpine TSi]

This is my 92 GVR4

The tranny upshifts fine, even with some hard pulls on her already. The one thing I have noticed is that while slowing down to change lanes, get on an off ramp to another highway, etc... where I am required to shift from fifth to fourth or third because I am slowing down and it would bog if I stayed in fifth, it is very hesitant to downshift unless I am going slower than around 40. If I try to downshift it will either grind, not go in, or go in with a profound thud. I never force it if it doesn't want to go, if I need to I will just slow down enough to where it will go in gear with problem. But that starts to become difficult in rush hour traffic. I have noticed that if I blip the throttle a little while I have the clutch in and coasting it will usually slip in. Also the clutch engagement is fine on it, the clutch was replaced by Shindley recently and broken in appropriately.

The tranny downshifts fine when I come to a stop but I do find that I have to wait a little longer in order to so(ie I always reverse cycle the gears, if I was in fourth I will shift, third, second, then to first if coming to a stop, I will do it slowly as I am coming to the stop, I don't know why I do it, but I find that it helps me shift back into first this way, on just about every manual tranny I have ever had).

Anyone have any ideas? I am thinking about changing over to Redline or such in there to maybe help it, but fear a rebuild might be needed.

Thanks in advance.