self-propelled mower won't propel

I've got a Craftsman mower (917.372852, roughly ten years old or more)) that worked fine until one day last week when cutting heavy, wet grass. Since then, the self-propelled mechanism has little power. It'll work on a bare surface but gives up whenever there's any resistance. So the behavior is like night-and-day, from before that one day.
I took the top cover off and can see that the belt looks okay and the inside area is *not* all clogged with debris. However, I cannot see where the belt wraps the pulley underneath the engine, on the main shaft. That part has a heavy cover underneath, that prevents access but also presumably prevents grass from getting up in there.
Drying for a week didn't help.
What should I check next? What part would be slipping?
Thanks.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 6/1/2011 12:33 PM, Tom wrote:

The belt tensioner would be first guess....I've got slow dialup so didn't try to look up parts diagram to see the particular details, but that's where I'd start to see how it actually is put together.
Got to be some way to replace the belt so keep digging to see the drive end/in-betweens. The answer's gotta' be in there somewhere. Or the hand lever isn't actually moving the idler linkage to engage it, perhaps?
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Agree. I have a Craftsman that is about 5 years old and it had the same problem. There is a spring about 4 inches long under a plastic cover at the rear top deck area. It broke. If that is what it is, you may be able to fix it, temporarily at least, with some bailing wire or a plastic tie wrap. Work the drive lever while you look at how the mechanism moves.

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

See page 15 of this document:
http://www.managemylife.com/mmh/lis_pdf/OWNM/L0705211.pdf
Remove the Drive Cover from near the left wheel to expose the drive mechanism. Engage the the drive control.
You should be able to tell what the cable is controlling and from there you might be able to determine the cause of the problem. Loose/ worn belt, cable not taught enough, worn gears, etc.
Good luck!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 6/1/2011 2:25 PM, DerbyDad03 wrote: ...

Where does one send a cable for more training it not previously well-taught? :)
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You start from the beginning:
http://www.nisd.net/schools/info/101
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The University of Tautology College.
-- Bobby G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 6/1/2011 3:25 PM, DerbyDad03 wrote:

thanks to all for the replies
yes, DerbeyDad, that is the manual exactly. Note the instructions on that page to change the belt say to begin by pushing down on the pulley. That pivots the pulley+gearcase down and loosens the belt. I don't see any way to adjust tension.
But note on page 22: there is some sort of clutch mechanism inside the gearcase. So, is it worth it for me to remove and disassemble the gearcase, or will that requires special tools to re-assemble?
[I ran the mower just now with the gearcase cover removed. The belt it always turning the pulley. When I push the lever on the handle to engage the drive, that moves the shifter (part 3 on page 22 exploded view), which apparently works part 11 Clutch Yoke. From the diagram, I can't tell how the clutch works.]
As a fallback, would it be possible to disengage the wheels from the drive mechanism to make itr all run justr like a regulkar mower? It's twice as hard to push a self-propelled that isn't working right.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

If you have never in 10 years removed this cover, it has perhaps accumulated enough debris to interfere with the drive mechanism.
--
Don Phillipson
Carlsbad Springs
  Click to see the full signature.
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.