[bobneumann]

Gentlemen,

When I bought my 442 it had a nice deck with it. Before I installed and mowed with the deck, I inspected it, did my best to lube it etc. As part of that, I noticed that the 3/4" nut on top the the main spindle pulley was missing. The pulley didn't seem loose, but it obviously was supposed to have a nut. So I bought one, and installed it, tightened it "as much as I could" using big channel locks to grip the shoulder of the pulley.

2 mowings later, and the nut is gone. The pulley's still snug, but no nut.

Is this a common problem? Am I just not putting enough torque? Do I need a self-locking nut?

Thanks in advance,

Bob

 

[dbeiter]

I think the factory nuts were self locking. I always install mine with an impact wrench..

 

[mikebramel]

impact wrench or a v belt wrench

and some lock tite or those nuts with nylon

 

[Hydriv]

The OEM nuts are a locking style. They have been hit on one of the "flats" to cause a small bit of distortion. However........as Mike suggested......Loc-tite will do the job too. Whatever method you employ, the nuts are supposed to be torqued down to make sure that the bearings, spindle, pulley, spacer and washers all rotate as a unit at all times. If there is not enough tension, then the spindle will begin to spin inside the bearing when the bearing runs out of lube and that will destroy the spindle.

 

[xfolkboat]

The factory nut is not only a locking type-one side is "staked", so be sure it goes on the right way-it is thinner than a standard nut of the same thread, so the nut and shaft are near flush.

The right way is staked side up, by the way.

 

[Bart]

The factory nut is not only a locking type-one side is "staked", so be sure it goes on the right way-it is thinner than a standard nut of the same thread, so the nut and shaft are near flush.

The right way is staked side up, by the way.

What do you mean by "staked"? I haven't noticed anything that suggests those nuts go one way or the other.

 

[Rockdog]

My deck has Prevailing Torque nuts. This is done by deforming the thread pitch diameter by 'squeezing' the outside body of the nut a controlled amount. On mine small rectangular indentations are visible on three of the six flats (they look like stake marks).

Is there a difference in threads between the left and right discharge decks? Just wondering if there is it may be possible someone replaced one with a 'wrong' spindle.

 

[Rockdog]

Folkboat is right regarding 'staked side up'. If you can get the nut started on the spindle withthe 'staked side' down then you need new nuts. They only provide prevailing torque to 5 or 10 installs anyway as i recall - which is fine for most mowing decks I'm assuming.

 

[Hydriv]

Just to clarify one point.


The spindles for the RM Series Right Discharge decks will fit into the mandrels of the Letter Decks (left discharge) because the mandrels and bearings are identical. However, the spindles for the RM Series are inserted from the top down because the pulley is welded to the those spindles but the Letter Series spindles are inserted from the bottom up because the blade mounting plate is welded to the bottom of the spindle.

Letter Decks have blades that use two bolts to secure them. RM Series decks have blades with a star-shaped hole and a single bolt to secure them.

Left Discharge decks have the blades spinning in the opposite rotation to the Right Discharge decks there for, everything about the blades is also the opposite.

 

[Rockdog]

Tom - Oh, yeah, different setup between the two types. How does the RM decks get driven? I dont see a pulley for the drive belt inthe parts manual....

 

[Hydriv]

viewtopic.php?f=26&t=733

Manual 8-3073 Page 17 Item 12 in lower drawing.

shows the center spindle with two pulley fixed to it.

 

[xfolkboat]

The factory nut is not only a locking type-one side is "staked", so be sure it goes on the right way-it is thinner than a standard nut of the same thread, so the nut and shaft are near flush.

The right way is staked side up, by the way.

What do you mean by "staked"? I haven't noticed anything that suggests those nuts go one way or the other.

On one side of the nut, it looks like someone put a screwdriver blade near the inside diameter of the nut and whacked the end of the driver with a hammer, leaving a mark where material was smooshed in a little bit-in 3 places on the last nut I bought.

We called this staking in the machine shops I worked in. It was used to hold in bearings in bores that had worn or were machined oversized, or where the designer didn't want a press fit.