Moen Shower Knob : Screw Won't Come out

Have a single knob Moen shower assembly, the kind you pull out to turn on the water and turn left and right for temperature control. I believe the knob is broken as it turns completely around but doesn't change the temperature. When I pop off the cover I get the screw to turn and turn but it never completely comes out. Any thoughts?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Sounds like it might be possible that the shaft is spinning. Sometimes you can slide the cover under the knob back and see the shaft. You may be able to drill the screw head off. Otherwise you might have to carefully break the knob so that you can remove it from the shaft. Moen has a lifetime warranty on most of their stuff. But it will be a lot easier if you can fix it without simply replacing the whole thing. Unless you can get at it from behind.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thanks for the answers. If the shaft is spinning is that another problem to be worried about? Does the fact that I can change the temperature of the water by turning the screw help with diagnosing the problem, or is that to be expected? If I break off the old knob, won't I still be unable to get a new one on without getting that screw out?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes, that does change the diagnosis. It sounds like turning the screw is operating the valve as designed. The problem is likely that the plastic ribs or flat spot inside the knob is stripped out causing the knob to simply spin on the shaft. You need to get the plastic knob off and without seeing it it is difficult to advise you. I think that if you can get the knob off then you should be able to grip the metal shaft with some pliers and then loosen the screw.
I don't know how you can get the knob off except to break it. A very small chisel applied to the knob plastic around the screw head perhaps? Or a cutting bit in a dremel? Just some thoughts.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes, that does change the diagnosis. It sounds like turning the screw is operating the valve as designed. The problem is likely that the plastic ribs or flat spot inside the knob is stripped out causing the knob to simply spin on the shaft. You need to get the plastic knob off and without seeing it it is difficult to advise you. I think that if you can get the knob off then you should be able to grip the metal shaft with some pliers and then loosen the screw.
I don't know how you can get the knob off except to break it. A very small chisel applied to the knob plastic around the screw head perhaps? Or a cutting bit in a dremel? Just some thoughts.
My thoughts also. Use Dremel or a hacksaw blade. .Cut into knob a ways and then stick a screwdriver into slot and twist to crack knob and remove. WW
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
WW wrote:

The OP might be able to grab the shaft behind the knob with a small vice grip or other type of small pliers, and remove the screw.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thanks so much. When I get home I will try this! BTW, it's the teardrop shaped knob.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 3/14/2011 1:59 PM, Jeffy3 wrote:

Pull out on the knob as hard as you can without breaking it while turning the screw out.
If it comes apart and a new screw works you are OK, if not you need to replace the shaft.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I would not expect that to work. The shaft is spinning inside the knob. There is a remote chance that pushing the knob sideways while turning the screw would work.
Moen will send a free knob if you can figure out the model number and tell them you are the original owner.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 15 Mar 2011 05:25:47 -0700 (PDT), jamesgangnc

Try pushing in hard on the knob. If the knob will push back on the spline, you may be able to hold the knob inward (holding the shaft spline) and gently back the screw all the way out. Only then pull the knob off.
--
Mr.E

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 3/15/2011 8:25 AM, jamesgangnc wrote:

Guess I got that backwards. I thought the shaft only turned as far as it normally would from hot to cold and then stop... then the threads were stripped and wouldn't come out with forward pressure on it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.