What stops this pulley from spinning on the shaft

[Butch 194]

I can not figure out what stops this pulley from free wheeling on the shaft. The pulley is not pressed on. Shaft isn't a "D"

shape. No key. Now both the double pulley and shaft were destroyed on my mower deck. Is the 80 lbs to 120 lbs of

torque what will stop the two parts from free wheeling. Very poor design. Expensive repair.

 

[gwest_ca-(File Mod) 11,032]

As long as the pulley will spin freely on the shaft the torque will hold it there. The direction of belt rotation tends to tighten it even more as long as a standard nut and lockwasher is used so that can happen.

 

There is a service bulletin for the spindles with keys and a nylock nut to eliminate the key and replace the nylock nut with a standard nut and lockwasher.

 

Garry

[Butch 194]

Thanks Garry. I don't think the pulley is to spin freely because there isn't a bearing in it. Just a sleeve. The pulley is supposed to stay

tight with the shaft and the shaft with the pulley spin in the bearings.

[daveoman1966 3,745]

I think you'll find a slight shoulder machined on the shaft which stops the pulley flor sliding on any farther.  The nylok top nut torques the pulley against this shoulder.   

[gwest_ca-(File Mod) 11,032]

Thanks Garry. I don't think the pulley is to spin freely because there isn't a bearing in it. Just a sleeve. The pulley is supposed to stay

tight with the shaft and the shaft with the pulley spin in the bearings.

The pulley must spin freely on the shaft before the nut is installed and torqued. If it did not spin freely the natural belt direction of travel may not keep it tight. Should the pulley want to turn on the shaft the lockwasher will take the nut with it making it even tighter.

 

That statement is likely intended more for those that remove the key and go with the standard nut and lockwasher. The keyways could have a burr that would prevent the pulley from spinning freely on the shaft.

 

Good application to use Neverseize on. No more trouble trying to remove a pulley later on.

 

Garry

[Don1977 604]

That 80 to 120 ft pounds torque is what keeps the pulley tight. The center of the bearings line up sleeve between them and the spacer at the top that is what  your are tightening against.

[Pickle 43]

I'm thinking the 80-120 ft/lbs torque was intended for the blade end of the shaft - you might try searching some of the manuals for the pulley end torque spec.

[Don1977 604]

I'm thinking the 80-120 ft/lbs torque was intended for the blade end of the shaft - you might try searching some of the manuals for the pulley end torque spec.

Your right on the blade. I looked at my information on the metric spindle it's 50 to 90 ft/torque. I use an air impact and and don't have a torque wrench, but I've never had a problem with loose pulleys.

[Butch 194]

I gave the pulley and blade 90 lbs. I put a ratchet/wrench at each end of the shaft and when the torque wrench hit 90 I figure both ends were at 90. Now please don't someone

tell me that one end could be 90 lbs and the other end 70 lbs. I have some new bearings which are the ones this deck uses. So now I'm replacing all the bearings. Might

as well since I have the deck off and apart.

[Butch 194]

Wouldn't ya know that the new double pulley sits 3.5 mm lower than the ones on the ends.

My typical luck!

[gwest_ca-(File Mod) 11,032]

Would flipping the pulley over correct it? Have seen this mentioned in some parts lists depending on the mower deck model.

 

Garry

[Butch 194]

Would flipping the pulley over correct it? Have seen this mentioned in some parts lists depending on the mower deck model.

 

Garry

No Garry. Won't work. I'm goin to use washers. Thanks.

[.5racer 14]

the lock washers are you most important part here . They act as a key as they are your drive.  New ones would be best , with the most lock and tension,. the othe choice would be going to a local machine shop and get shaft and hub keyed !!!!

[Butch 194]

I have the deck back together. I used 2 washers under the center pulley. When I went to take the center pulley off

so I could add the washers the pulley wouldn't come off. I had to beat the shaft out to free the pulley. So that means

the pulley is pressed on. I put brand new bearings in all 3 units and lubed them with Amsoil grease.

[Don1977 604]

None of those pulleys were pressed on.