I have decided to rebuild the 4l60E out of my 97 S10 Blazer. Here is the problem, I took it out of the Blazer about a year ago and through it in the back of my pick-up and left it there, and then left the pick-up out back. upon dismantling the tranny i found some rust inside from sitting for a year, there are 2 main places that concern me. 1) Reverse Input Drum - the band seems to have stain it, but i can feel the imprints but there not that bad, and i used 400 grit wet sandpaper on it. 2) The place were the servo goes, again i used 400 grit to clean it, and this time i can feel on difference between the part that had rust on it and the smooth part.

do i need to replace the reverse input drum and can i just put a new servo in it. I'm going to try to post pics so you all can see what I'm talking about

 

I would get a new servo and you will have to be carefull with the o ring for the cover. It my leak with the picture you show. the drum I would not worry about. I am no expert but rebuilt enough 700R4 to have a good clue

 

thanks for the reply. your right with the servo, it's were the cover goes on, but it looks worst then it is, i can run my finger around it and it feels ok, just like the one below it. as for the drum, you dont think it's going to be a problem? i thought i might try some 320grit cause i can feel a bit of a raise were the marks are, what do you think?