Sorry OP don't mean to hijack your thread but.what exactly does the 4th servo do? does it have a crispier shift on 3-4 or does it hold the 4th gear longer on WOT?
is this worth the upgrade ? i already have the corvette servo and wondering if i should also throw on the 4th Servo

 

Pretty much the same thing as the vette servos just for the 3-4 shift

 

Sorry about the hijacking

My bad, it's a Superior 4th servo

 

No worries about hi-jacking guys. Did the superior servo come with any instructions? Maybe Vince b will chime in. He seems to be a pretty knowledgeable guy when it comes to these kind of things.

 

The spring on the superior kit if I remember correctly is for the servo pin if in fact we are talking about the 4th servo. If this is what I'm thinking off the little spring is blue in color. The solid billet (not recommended) 2nd gear servo comes with a spring which replaces the factory return spring. This is the inner most spring in the bore and I believe it is red from superior. HTH Vince

 

Well I finally got everything sorted out, got the washer installed in the right place and everything but it's still not shifting into 4th. It shifts fine and dosent make and noises or anything just dosent go Into 4th gear

 

Yep, mine is superior & it came with the blue spring