46 riding mower. Why don't blades disengage?

if you just replaced the bearings and now the belt is to loose tells me the belt wasn't put back on correctly. replacing the bearings don't have anything to do with the adjustment of the belt. double check to be sure is is on right Lisa. something isn't right. the tension should come from a spring loaded arm that when engaged it will apply a certain amount of pressure to turn the blades. if disengaged it will seam loose but that is ok. it has to be loose to let the belt slip on the pulleys.

Terry, Deck full of debris around belt tensioner not allowing it to release, tension arm seized/spring broke, wrong/small belt installed.
Check the attached links,instruction and guides, Good luck
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CRAFTSMAN 42 MOWER REPAIR
My mower deck will not disengage
Blade will not disengage Craftsman 917 270662
https://answers.yahoo.com/question/index?qid=20090407155731AACRvsq
Sears Craftsman 917 272481 LTX1000 Riding Mower Deck Belt Blade...

Check your blade belts.

when you actuate the "engage blade" lever, two things may occur,
First, a mechanical action, a spring moves to put tension onto the belt.
Second; at the end of its run, actuate a switch (PTF switch) to engage the clutch that moves the pulleys that consequentially move the blades.
if the tensioner is not moving , check if spring has come lose, undone or broken, (more likely in your case) or check the PTF switch.
any other assistance, contact me, good luck.

If you need further help, reach me via phone at https://www.6ya.com/expert/gerardo_79638d1eac6a0a1f

Sounds like either the switch for the blades is not shutting off the power to the electric clutch or the clutch itself is not disengaging. I would shut the mower off and unplug the wire to the electric clutch and then start the mower and make sure the blades do not turn you may have the belt for the blades on the wrong pulley and it might be causing the blades to turn. Hope this helps.

If you lower the blade deck and get down near the mower, you can see the blades belt on top of the deck. If it is intact, with the engine off, have someone try to engage the blades. A tensioner should move into place to tighten the blades. If it is not, follow the engagement lever to under the dash to see if there is a cable broken or a rod detached.

Post back.
Gary

check the pullie blade bearing if it is going out it would make the belt squeak and when it gets hot it will make the motor lug down I have worked on mowers for 41 yrs.

A new belt might be the way to go

This is too late, but for the next person: There is an extension spring around the cable attached to the blade engage/disengage lever.

On my tractor one end of the spring had the hook broken off or it. Because it is around the cable it is still in place but doesn't stretch when you engage the blade (so can't pull the pulley out and slacken the belt when you disengage).

The replacement is a few dollars and can be bought on ebay or Amazon.

Need to adjust the tension on the belt.