I'm trying to do maintenance on my secondary and it won't come apart. Removed the snap ring, and it took some work to get it to move on the shaft. I can now bottom it out, but the helix will only come apart flush with the shaft. Then I used wood wedges and a large clamp to split the sheaves apart, but I could only get it to move another 4-5mm. Seems to hang up at that point. Anybody got any magic insight?