009 3 speed transmission problem

Hi all. I have an 89 t25 with a 009 3 speed auto. i think is needs a rebuild soon, but wonder the cost and if there is another fix first. problem is this.

when cold starting, and put into reverse and to a lesser extent drive, wont move. takes a few minutes to warm up and i think build up pressure before it will move. when cold in park makes a whining noise that goes along into reverse.

When warmed up all is good. I have changed the fluid four times and it is better. running an additive that is supposed to help the seals etc, but i dont have any experience in autos, so not sure if it does anything much. Since using the additive, fuel economy is slightly better, as is power.

Is this a complicated fix or reco. and what would be approx cost.

Thanks.

Mark

mate i feel your pain been there done that there is really only one way to fix and that is replace the box rebuild won't help praying dont
god luck

any idea where i can get a rebuilt one in victoria and how much it will cost. Thanks.