Grading Blade tightening???

[Sumosized]

I broke one of the PTO belts on my 3240 on Sunday when my mower deck got bogged down while I was trying to mow some pretty high stuff. Since it was Sunday and the local dealer was closed, I decided to pull the deck off, clean under it, and sharpen the blades.

I have a 48" deck (shaft driven) and when I put the blades back on, I used two wrenches and tightened them as tight as I could get them--with a 345lb. man pulling on a 14" wrench, that should be pretty darn tight. I could hold the pulley with a wrench and turn the blade. Is this right? There's a pretty big "washer" under the blade, the nut stays put and the blade moves with the washer. Is this some type of a slip clutch?




BTW, I put the new belts on tonight and the deck runs better than it did when I first got it. There's a bit of a "hot" smell coming from the belts, but all the pulleys are moving fine and nothing's rubbing--should just be the new belts breaking in.

 

[OhioGuy]

Sumo,
That just doesn't seem right. I've owned a number of Cubs and all the blades tighened up to a point you'd use a block of wood to prevent them from turning to tighten or loosen them.

As I recall, there is a large (2 inch) flat washer on both sides of the blade.
Maybe one is missing and the thread depth on the spindle can't snug it down?

I think the first time you get into any heavy cutting the blades will stall and the shafts will continue to spin.

I'd suggest looking at the decks parts diagram at cubcadet.com and see what might be missing.

Good Luck
Curt

 

[TractorLarry]

When I changed my blades I used a chunk of 2X6 to wedge between the blade and deck housing, and torqued to what my manual showed. I think it was around 100ft. lbs. but I don't remember for sure.

-Larry

I broke one of the PTO belts on my 3240 on Sunday when my mower deck got bogged down while I was trying to mow some pretty high stuff. Since it was Sunday and the local dealer was closed, I decided to pull the deck off, clean under it, and sharpen the blades.

I have a 48" deck (shaft driven) and when I put the blades back on, I used two wrenches and tightened them as tight as I could get them--with a 345lb. man pulling on a 14" wrench, that should be pretty darn tight. I could hold the pulley with a wrench and turn the blade. Is this right? There's a pretty big "washer" under the blade, the nut stays put and the blade moves with the washer. Is this some type of a slip clutch?




BTW, I put the new belts on tonight and the deck runs better than it did when I first got it. There's a bit of a "hot" smell coming from the belts, but all the pulleys are moving fine and nothing's rubbing--should just be the new belts breaking in.

 

[Sumosized]

When I changed my blades I used a chunk of 2X6 to wedge between the blade and deck housing, and torqued to what my manual showed. I think it was around 100ft. lbs. but I don't remember for sure.

-Larry

I tried doing that, but the pully still turns--both on and off. The owners manual says that this model (289) uses a keyed spindle shaft and pulley, with a hex jam nut securing the pulley. It says to use a 1-/4" wrench to hold the "hex shaped hub" on the pulley while using an 1-1/8" wrench to loosen the nut.

Anyone have this deck model? 48" Model 289

 

[OhioGuy]

Is just one spindle behaving this way?
When you turn the pulley, does the spindle shaft turn with the pulley?

Did a key fall out of one spindle?

Curt

 

[Sumosized]

All three blades do this. I cut a flat 50'x100' section with it tonight. The grass wasn't very high and it was very dry. Talked to the local dealer and he suggested that I may have slipped the key. I can see this happening to one spindle, but all three?

I'm going to have to take the deck off tomorrow and check it out again.

 

[Sumosized]

FIXED

I bought an electric impact gun from Harbor Freight last noght for $34.99 and a set of SAE impact sockets for $14.99. Turned about 1/8 turn and poof--no problem. I couldn't spin the blades under the nut before I used the impact, I think they finished tightening when I tested the mower the other night, but I wanted to be safe!

Thanks

 

[OhioGuy]

Glad you're back in business!

I'm a big fan of Harbor Freight, I bought a 3/4 drive socket set for tractor work, I think the breaker bar weighs 5 LBS, it's massive.

Curt

 

[5030]

The torque specification is 120 foot pounds for my M60 Tank ZTR with 1-1/8" hex nuts on the blade spindle ends. I'll presume it's the same for yours.

Every time I buy something from Harbor Fright it breaks.

 

[Sumosized]

The torque specification is 120 foot pounds for my M60 Tank ZTR with 1-1/8" hex nuts on the blade spindle ends. I'll presume it's the same for yours.

Every time I buy something from Harbor Fright it breaks.

I bought a bandsaw there and use it A LOT, never had a problem.

Is it possible I have the nuts too tight now?