Again, this is a known issue and has a solution. The following in an excerpt from another forum
Friday, March 7, 2008
Performa Valves Keep Breaking 440i Timers - Solution is...
* Problem:
We have dual tanks for well water with 268/440i controllers. One is for an iron filter, the other a brine tank. We are running into a situation where timers have been destroyed because the camshaft is too hard to turn when they go to a refill cycle. (It took a while, and a couple of timers, to figure this out.) We relieved the pressure on each tank, checked the flappers, and couldn't see a problem. They moved very easily while the pressure was down. Once we got the system up to pressure, though, you really have to shove the refill valves hard to get them to move. (First it was the iron filter, and now the softener valve has the same problem.) Have you ever heard of this?
* YES!!
I would think that I need to replace the flapper valves and timers, but is there something else we should look at?
* Not Flapper Valves, but the Timer and Camshaft.
We checked for obstructions, and I don't think that's the issue.
* The issue is the Timer and Camshaft.
Autotrol has Revised the Timers ( effective January 2008 ) and they have Revised the Camshafts to help prevent this very common problem ( note: it helps, but you still have gears breaking, just not as quickly ).