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Loose Deck Pully


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The main on the main spindle of this 48" deck, the pulley that I'm touching in the picture spins freely. Because it is spinning freely power isn't transferred to the other blades. 

I'm not having any luck freeing the screw on pulley/ mount to investigate. 

The deck has no stickers or other identifiable part numbers.

If you know what's supposed to hold the pulley in place let me know. It came free when a chunk of old copper wire hidden in the grass stuck in the deck.


Thanks in advance. Have a happy 4th.




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I think this is the IPL for your deck (MFG #990886):


1 2108679 3 Tube Assembly, Arbor
2 2108250SM 2 Arbor Assembly
3 2108181 9 Washer
4 2108202SM 6 Bearing
5 2108257SM 3 Washer
6 2108201SM 3 Spacer
7 2719001 1 Plain Washer, 3/8"
8 2177005SM 3 Pulley
9 2725006 3 Woodruff Key, (No. 61) 3/16" x 5/18" Dia.
10 2161130 1 Hex Capscrew, Special
11 2717517 2 Hex Lock Nut, 3/4"-16
12 1685004SM 1 Arbor Drive Assembly
13 2108436SM 1 Spacer
14 2176340 1 Pulley Hub
15 2174190SM 1 Pulley
16 2715174 3 Screw, Washer-head, Taptite 3/8"-16 x 1-3/4"
17 2108139 3 Flinger
18 2717517 1 Hex Lock Nut, 3/4"-16
19 2108448 3 Knife Blade
20 2715024 6 Hex Capscrew, 3/8"-16 x 5/8"
21 2720002 6 Lockwasher, 3/8"
22 2705004 16 Hex Capscrew, 3/8"-16NC x 3/4"
23 2156131SM 1 Stop Stud
24 2720002 20 Lockwasher, 3/8"
25 2719002 6 Plain Washer, 5/16"
26 2717003 20 Full Hex Nut, 3/8"-16
27 2108449SM 1 Tension Spring
28 2108473SM 1 Idler Lever Assembly
29 2705010 1 Hex Capscrew, 3/8"-16 x 1-3/4"
30 2108386SM 1 Idler Pulley
31 2108418 1 Screw
32 2108450 1 "V" Belt, Mower
33 2163011 1 "V" Belt
34 2108472 3 Washer
35 2108822 2 Arbor Assembly with Bearings and Hardware
36 1729274SM 1 Inner Race
37 2157332 1 Key

From your second pic, it appears part #18  is missing and rust is keep the upper driven pulley on the shaft.  The pulleys use keys to keep them from spinning; so the lower woodruff key (part #9) must have sheared.   Some of the pulleys have set screws over the keys, but the above IPL doesn't show any and your pic of the upper pulley hub has a set screw hole, but to my eyes doesn't appear to have a set screw in it.  

To get to the bottom pulley you're going to have to remove the upper pulley assembly.  I'd do that in two steps - first remove the upper pulley from the hub (the 3 bolts), then use a puller/penetrating oil/heat to get the hub off the shaft.  Since the lower pulley is rotating, I would think it would come off easy so you can replace the key.  

Hopefully the lower keyway isn't damaged too much and a new key can be installed that will work for you.  


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4 hours ago, PhanDad said:

From your second pic, it appears part #18  is missing and rust is keep the upper driven pulley on the shaft.  

Part number 14 had a set screw holding it in place. I can get #14 to rotate a fraction of a degree. I fear it may be caught up shaft damage from the set screw. I hope this wasn't a user fix for missing a nut.

Thanks for the parts diagram. I'd been looking for a week now.

Edited by jamac1321
Fixed part number
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It looks like part 14 also has a key. I don't know how remove that....


Wondering if the answer is to weld #14 to the spacer, and the spacer to the pulley making it one unit. I don't like to do hack fixes though.



Edited by jamac1321
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21 hours ago, jamac1321 said:

It looks like part 14 also has a key. I don't know how remove that....

You don't remove it before you pull the pulley hub off (part #14).  The entire length of the hub shaft hole is machined to fit the key.  The pulley is both installed and removed with the key in place.  

The rust doesn't look as bad as I expected.  I would think some penetrating oil and a puller would remove the hub without the need for heat.  

Or you could take the whole arbor assembly and they could press the shaft out of the hub.  I think there's enough room beneath the pulley hub to allow the press table to close under it.  


Edited by PhanDad
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The key holding the pulley in place blew through the side of the arbor shaft. I'd be tempted to weld material on the shaft and grind it back down, but the pulley has some key fragment stuck in it and my attempt to remove it was only damaging the pulley. Maybe I should weld the pulley in place on the shaft since is it almost junk anyway. Open to suggestions.




Side note. Bought a 15 steering wheel puller at Harbor freight. It had bolts that threaded right into the pulley hub 14, and pulled it off like a dream.



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My deck is older than yours. The nut continually came loose, causing problems on the shaft. That bottom pulley is sacrificial, have one in stock before attempting anything on the center arbor. Brenda at Sandy Lake usually has them in stock. You may get by with a longer key, since the keyway extends above the pulley. That is a short term fix to keep from buying an expensive shaft. I had my last center shaft custom made several years ago, instead of buying a factory shaft, for different reasons than cost. That does not look like a factory shaft. The IPL above shows 2 woodruff keys. That long keyway is not made for those keys.

To finish the season at least cost, get a new pulley, a longer key that extends up past the pulley, preferably all the way to and into the hub above, and put it back together. Liberal use of anti-seize on all metal parts/shaft will make removal possible in a short term situation. Proper repair includes a new shaft, proper keys, and lots of anti-seize. A good machinist can build the shaft up turn it down, and recut the keyway. Likely, this will cost almost as much as a new shaft, unless that machinist is a good friend

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  • 3 weeks later...

So, I was able to get the shaft pressed out. 

I used my stick welder and some 6010 to build up the metal.  

I ground the shaft back down to round with a grinder.

I used my Dremel and some small stones to cut the keyway back into the shaft.  New bearings, new woodruff key and put everything back together. 

I replaced the bearings in the 2 other spindles as well. The deck sounds more like vacuum and less like a paint shaker.

5 hours mowing over greenbrier on the repaired deck. Hoping I another few hundred.


Thanks for all the help.


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Dam you got lucky. When my nut came loose it took my whole assembly out minus the actual pulleys. I purchased new parts but that stupid part that bolts to pulley was redesigned and wouldn't bolt to my large pulley anymore. Been without my 48" deck for a year or 2 now. Finally found another 48" deck locally for parts. 

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