RC72 Mower Deck - middle blade loose and will not tighten

[gorilla]

The middle blade on RC72 mower deck stopped mowing over the last couple mows. I noticed the blade was loose. I tried to tighten with a socket and breaker bar. I was able to remove the blade and then try to re-install, but no matter how hard I try it will not tighten all the way.

Any ideas? It is directly under the gearbox - not sure if there is anything else to adjust?

 

[85Hokie]

The middle blade on RC72 mower deck stopped mowing over the last couple mows. I noticed the blade was loose. I tried to tighten with a socket and breaker bar. I was able to remove the blade and then try to re-install, but no matter how hard I try it will not tighten all the way.

Any ideas? It is directly under the gearbox - not sure if there is anything else to adjust?

What do the threads look like on the bolt? Have pictures? Both washers there? Cupped the correct way?

 

[gorilla]

The threads look fine and both washers are there and cupped with dome towards the ground.

 

[85Hokie]

The threads look fine and both washers are there and cupped with dome towards the ground.

What happens if you remove a washer? Will it bite? I am thinking the threads are bad in the spindle.

 

[Kanook]

Is it possible that an incorrect length bolt may have been installed at some point that is a bit too long and is bottoming out?

 

[gorilla]

I will take out the bolt and measure it but since it was fine for the last couple months and is now having an issue, I did not suspect that to be the problem.

I was thinking it had something to the do with the spindle or gearbox

 

[JeffL]

I have had a similar problem and found the spindle was rotating and pulley was sliding on the belt. Worth a look. Jeff

 

[skeets]

Tips for correct Belleville washer installations For some materials, you use a flat washer under the Belleville washer, and for some you can't. The softer the material, the more likely you'll require a flat washer. If you find the Belleville is too large, do not try to compensate by placing a flat washer underneath it.

Mount the washer so its cup points toward the connection (away from the bolt head or nut). Mounting it upside down (reversed), adds little clamping force to the connection. The number of reversed Belleville washers in existing installations is staggering, so it is an important consideration.

If you have the cup pointing toward the NUT then it is upside down

 

[CountryBumkin]

"Dome" toward the ground. That sounds wrong. Maybe I'm misunderstanding "dome". The "U-shape" needs to have the top of the "U" be against the blade so when you tighten the bolt the washer compresses and helps hold the blade in place.

At least that's the way it goes on the RCK60 model.


@Skeets - you beat me to it,

 

[gorilla]

The cup of the washers is pointing up towards the spindle

 

[gorilla]

Picture attached.

 

[tempforce]

on the pulley side of the spindle. can you rotate the pulley with the blade held in a fixed position?
possible loose pulley nut.

double check belt tension on the pulley with pto engaged and tractor shut down. (engage pto, then shut down tractor).
if you can rotate the blade with belt tension engaged and the engine off. the belt is too loose.. needs replaced.

 

[85Hokie]

Picture attached.

Gorilla -

your picture is exactly right!

here is another picture

 

[gorilla]

I decided to remove the gearbox and pulley to see if I could find anything. Not sure if this is related or another issue but once I removed the gear box and spindle I found that the bearings in the deck that go around the spindle below the pulley are bad. It only has about half of the bearings in it and some small sharp chunks of metal.

How do i remove the bearings? Do I need any special equipment?

 

[Diydave]

I decided to remove the gearbox and pulley to see if I could find anything. Not sure if this is related or another issue but once I removed the gear box and spindle I found that the bearings in the deck that go around the spindle below the pulley are bad. It only has about half of the bearings in it and some small sharp chunks of metal.

How do i remove the bearings? Do I need any special equipment?

If you are a novice at it, you may find buying the complete gearbox and spindle cheaper, and faster than trying to rebuild the one you have...

 

[gorilla]

The bearings are attached to the deck and the spindle and pulley are removed and fine.

Just did not know if I need to remove the whole pulley holder to remove the bearings or if there is a way to get them out while keeping the pulley holder attached to the deck?

How do I remove the oil seal on either the top or bottom of the bearings?

 

[whitetiger]

The bearings are attached to the deck and the spindle and pulley are removed and fine.

Just did not know if I need to remove the whole pulley holder to remove the bearings or if there is a way to get them out while keeping the pulley holder attached to the deck?

How do I remove the oil seal on either the top or bottom of the bearings?

Use a pry bar under the lip of the seal, they pop out easily. There is a snap ring below the bearing to hold it in place. Remove the snap ring and tap bearing out of the bottom of the holder. Clean the inside of the holder to remove all grease and debris. Pack the new bearing with fresh grease, then tap it from bottom side up into place. Install snap ring, seals, blade boss and snap ring. Put the gearbox back in place, grease the bearing through zerk beside the gear box. Install your blade and see it it is tight and spins smooth. Put your belt and PTO shaft back on and go make tall grass short.

 

[gorilla]

Thanks I will give that a try. I was having a hell of a time getting the pulley holder off the deck.

 

[bulletman]

try running a tap in the spindle,,, those threads may be messed up, mine worked after that with medimum loc-tite applied to bolt, let dry before use if that tightens it up.

 

[gorilla]

I was able to replace the worn bearings in the lower pulley holder and put everything back together. The blade tightened back up and the mower worked great for a couple weeks.

I just noticed today that the middle blade was not cutting well and when I checked the blade it was loose again. Not sure what is going on. I may have to bite the bullet and send to a shop for a more professional examination.

I do not know if there is something in the gearbox that is bad that would cause the shaft to drop or slightly or if the bearing went out again. I am almost too frustrated to take it apart again.