Mower deck problem RCK 72

[ahenthus]

I noticed my middle blade was not mowing. After trying to tighten the blade bolt several times on the tractor I decided I'd have to remove the deck. With the deck off and up on it's side I attempted to tighten it again. It just wont tighten enough to hold the blade. It turns freely even after being tightened with an impact wrench. The threads are fine and the proper washers are in place. The two outer blades function great. The gearbox must be okay because there is no noise or rattle coming from it and it turns the other two blades. The shaft and bolt turn with the other two blades but the middle blade floats like it's not properly tightened. I don't relish taking it to the dealer because it's in another town and loading it on my truck is quite a pain. Any suggestions?

 

[loggin]

I noticed my middle blade was not mowing. After trying to tighten the blade bolt several times on the tractor I decided I'd have to remove the deck. With the deck off and up on it's side I attempted to tighten it again. It just wont tighten enough to hold the blade. It turns freely even after being tightened with an impact wrench. The threads are fine and the proper washers are in place. The two outer blades function great. The gearbox must be okay because there is no noise or rattle coming from it and it turns the other two blades. The shaft and bolt turn with the other two blades but the middle blade floats like it's not properly tightened. I don't relish taking it to the dealer because it's in another town and loading it on my truck is quite a pain. Any suggestions?

Did you replaced the blade and it is slightly thinner than the original?

 

[Sniggle]

Add another washer...had to do that when I rebuilt my RCK-60.

 

[Ken45101]

Is the pulley possibly slipping on the shaft?

 

[JWR]

You may have stripped the threads on the bolt holding on the center blade. With extreme luck you MAY find that adding a washer causes contact with a slightly differing depth of threads and MAY give you enough tension to hold the blade.

Another possibility is that the bolt is bottoming out in the hole. Are you sure this disease is new and not been occurring for a long time?

That is a very specialized bolt -- keep that in mind if you decide to re-thread the hole and use a new/different bolt. How do the threads look ? Are there the same number of washers on each shaft? Are they tapered and all on the same way/orientation?

 

[ahenthus]

Add another washer...had to do that when I rebuilt my RCK-60.

Good call. I put an additional belleville washer on and all is well and back on the Tractor. I also purchased a new bolt for my RCK-60. Wow, that bolt is now $26 at the dealer. JWR, the bolt was in perfect shape and was never in question. The new bolt was for a different deck. I guess I never said the troublesome deck with the freewheeling blade was my RCK-72.

 

[JWR]

Good call. I put an additional belleville washer on and all is well and back on the Tractor. I also purchased a new bolt for my RCK-60. Wow, that bolt is now $26 at the dealer. JWR, the bolt was in perfect shape and was never in question. The new bolt was for a different deck. I guess I never said the troublesome deck with the freewheeling blade was my RCK-72.

Understand. The mechanics of it are the same for my 60 inch deck. I still wonder if maybe the bolt was bottoming out in the hole and the washer just overcame that small depth difference?

 

[3gunr]

I had the same issue with my 20 yr old big bee 72 in mower, The outside blade quit cutting and would not tighten enough, Added a washer and all was well.

 

[kthompson]

Is it possible there is even grease build up in the bolt hole, but anything can build up and reduce the depth causing your problem, even dirt or grass. When you have the bolt off try a flat blade screwdriver in there turn it and pull it out to see if anything on the blade.