Mine was a little tighter, but honestly I like that. It didn't bind.
There's another problem I had, though, and my 'solution' to that problem may have inadvertently aided the spare belt to work. The shear pin that holds the "engage/disengage" handle on its shaft had broken on mine, so the handle was loose, and wouldn't engage the autopilot
. I drilled the hole of the shear pin out some, then drilled the hole through the shaft a little wider, then used a cotter pin to hold it in place. The upshot of that, is that my "engage/disengage" handle is much more firmly attached and much less likely to slip out while engaged, but it's got a little bit of wobble in it. That wobble may be enough to loosten the unit, so it works better with the new belt.
My autohelm, with the two semi-ghetto-fixes applied in tandem, is working better and more reliably than it ever has before.
If I were you, I'd check to make sure the 'engage' wheel is doing what it's supposed to. If it is, then possibly consider putting a little 3 in 1 oil along the interior plastic, to help it slide when not engaged, and the tightness of the grip might overcome the decreased friction when it is engaged. Be prepared to wipe it all off if it slips when engaged, though, and keep an eye on it in heavy weather for slippage.