I’ve had many customers before with a broken dial, and many of them have tried contacting Irritrol about it and they were sent a replacement in the mail for free! I would recommend trying that.
Once you get the dial, you’ll see how it’s constructed. Look for any broken part of the old dial that is still in the spot where the dial goes and pick it out with needle-nose players or tweezers if you can. Then just pop in the new one.
It should look like one of these when it’s all cleared out. You shouldn’t need to take the timer apart if you can get all the pieces out.
If we’ve been helpful and it’s saved you from spending ~$100+ on a new timer, please consider making a donation on our RainDialDoctor site here.
Note there are two pictures, one has a ‘T’ like structure in the middle that is more common. When the dial rotated to the top position, the leg of the T is on the left.