Mower deck Shreding Mower Deck V-Belts on my LT 1000 38"

[jascoesens]

Greetings,
I have a circa 2004 Craftsman LT 1000. About a week ago the deck V-belt broke. I figured It was normal wear. Replaced the belt and started up and and engaged the deck drive. Seemed to be working fine; however the belt shredded after 10-15 minutes of mowing. I had noticed the engaged deck was much quieter than when I 1st got it (inherited it 2011). I figured I had mis-routed the belt and maybe it was rubbing against something.
Replaced the v-belt again and checked and double checked the routing with the deck engaged (engine off) and the deck raised to my normal cutting height and everything looked good. The belt was not rubbing on anything except the 5 pulleys. The 2nd replacement lasted only 10 minutes.
Does anyone have a clue as to what is causing the rapid destruction of the v-belt??
James

 

[SeniorCitizen]

Have someone start it and engage the PTO with the engine throttle in idle position after it is engaged. Using the safety precautions necessary look at the belt and pulleys while it is actually in operation. For belts to last such a short time something is drastically out of alignment, locked up, sticking or other.

 

[jascoesens]

Thanks Sr. C
I will check-out your suggestions probably this weekend. Meanwhile I decided to remove the mower deck to see or feel what I could. I found the idler pulleys smooth and free spinning. When it comes to the spinning the blades & mandrels there is a very discernable difference. The right assembly turns smoothly and with little effort. The left assembly turns smoothly (no grinding) but with a moderate effort. I don't know if this is a significant issue causing the problem.
Questions:
I am considering REPLACING the Left Mandrel housing, shaft & bearing.
Do I need to replace all 3 items or Just shaft & bearing, or just the bearing?
Comments or suggestions?

 

[ILENGINE]

Make sure the spindle brakes are disengaged before turning the spindles. It can make then hard to turn. You can do any of the suggestions things to repair the spindle if need be. The bottom spindle bearing tends to be pressed onto the shaft. so unless you have a way to get it off and back on, your best bet would be to replace the shaft with the bottom bearing already installed. On some of the craftsmans, there was a brake arm that started about the middle of the deck on both sides. It is possible to get the belt on the outside of the brake causing it to rub and destroy the belt.

 

[jascoesens]

After removing the mower deck and figuring out how to release the mandrel brakes I discovered the mandrel & Blades spun easily for more than 30 seconds. I discovered a broken belt guide on the mower deck. It took ~10 days to get the ordered part sent to me. got every thing r&r. Put trans in N. Brake locked. Cinder block on seat. Deck raised to normal cutting height. Started engine & let it warm up some before throttling down to low idle. Carefully engaged PTO and very carefully inspected the deck belt routing. --> Low & behold, I finally noticed a belt keeper for the idler pulley that I had not noticed before. So, problem solved and I'm back in business.
Thanks for all the helpful suggestions.
Jascoesens