Need some servo help with my savage

My old steering servo went out so I got a new one (same as the original one) and it came today, so I was trying to install it and set everything back up. But the problem is that the notched plastic piece that comes out of the servo that hooks up to whatever you want to turn. (hopefully that makes some sense) Well that thing is not the same size as the servo that was in their originally and so the hole is too big for the thing that sits on the servo because the piece on the new servo is much smaller than the one that was on the servo that was in the truck.

How can I fix this? I haven't come across a problem like this before when replacing a stock part with the same stock part.

Thanks guys

[coolhandcountry]

I think you talking about the servo horn. I got a kit savage and it came with various sizes to fit different servos.

yes that is what it is called, I just couldn't remember the name of it. The new servo I got didn't come with any and the one I have is too big to fit on the new servo.

[coolhandcountry]

Does your have the cam type servo saver or the windup kind? It is weird the same servo has different spline count. Tower sells the parts but just have to know what you have to get it to fit.

[crazyjr]

check the old servo for a splined adaptor to adapt the servo to the horn/saver. Not sure if HPI did this, but Traxxas had different adapters for different servos