Ok so i have had a few problems with my steering servo on my hellfire....first my stock servo busted a gear so i had to replace it...so i went and bought a JR racing Z650M servo from my LHS and they told me that it wasnt the greatest for it because theres obviously better ones out there but that its more than enough for my hellfire. So today i went to drive it and idk what happened but the servo stopped working. The motor runs full blast in it but the servo doesnt turn the wheels. so i took it apart to see if the gears were broken or anything but i was doubting they were since theyre steel gears and they all look fine....so does anyone know what the problem could be?...the servo motor runs but the servo will not turn the wheels....any help or advice would be appreciated...thnx

Hmmm maybe the motor shaft is spinning freely inside it's pinion?

Thats all I can think of if all the gears are intact :/

This sounds about right you might of rounded the pinion gear.

just a thought.
the sf-2 is 23 tooth spline.
my jr servo's are 25 tooth spline.
so as above check for a striped servo horn.

new horn kit.
hpi # 85507.
http://www.hpieurope.com/piw.php?lang=en&partNo=85507

I think it is a stripped servo arm. I run the JR650M on my truggies and it works great. One thing you can look for is when you turn the wheels from left to right, look and see if the screw that holds down you servo arm to you servo and see if it is turning and the arm not turning. That is usually what you will see if the arm is stripped. The plastic servo arms strip out very easily and I replace all mine with aluminum arms and eliminate that problem. Also like mazdab2600 said some different companies have different amount of teeth on there servos and you have to get the right arm to fit them.

Remove the servo horn and check it again...

ok everyone....sorry its been a couple days but ive been out of town for the holidays. But ive taken the servo arm off and the servo still doesnt work...i took it apart and put it back together and the servo worked for about 2 times turning the wheels in both directions...then it started doing the same thing. It just rant but not of the gears engaged...im so frustrated with it right now...i dont know what to do next and i dont want to get another one when this one is brand new...hasnt even ran on the car for a full tank yet

did you ever get this problem fixxed .... you will have to look at the servo gears again ... they are very tiny and it doesnt take but just one of them to be missing to cause the problem that you discribe. The sevro will catch a couple of grinding times if you run it till it quits and then move the servo arm manually (by hand) and it will likly grind and carry on ... might even ingage again .... but I can almost lay money on it your gears are gone .. cheap fix .... the problem is with the hellfire .... I think I had a problem with my MGT as well ... but that is another story ... the steering posts need services reg. and the servo saver doesnt move free enough to SAVE the servos ... this is where I would begin to LQQK for you servo killing problem I pulled mine apart and rounded it up a little with some sand paper, after I worked it a bit I placed it back in the car .... a good test is to steer your car while someone holds your tires str8, your servo should move like it is sterring and the saver should be taking the torque, this is a nice place to start ... you can tighten up from there untill you get the responce that you like, just dont go so far that whne you have a big crash that you lose your servo because you went to tight ... this is from MHO as I have raced one of these animals for a couple of years when the SS version first came out. I hope all this helps and good luck with all your R/Cing fun.