Belly Mower Failure on BX2670

[JWR]

This deck is a RCK60B23BX model ser. 67407

Bought this tractor with 218 hrs on it from a dealer in PA. Was traded in on larger machine. As perfect a condition as I have seen a used Kubota.
The dealer had serviced it just before my purchase. I greased the deck at start of this season. It cuts about 2/3 acre each week. Daughter used it one year.
This week all H broke loose. Belt was shredded wildly / destroyed. She is hard of hearing but heard a screaming noise & shut off the deck. Could see nothing wrong,
[not savvy enough to look at the belt] turned the deck back on and ran about 10 feet before final shut down. By that time the belt was totally gone as it was when I got there.
There were no sudden halts or objects hit, roots, big rocks, etc.

A week ago the deck would not initially turn on but after cycling the control it ran normally and mowed the full area as usual.

On disassembly the key on the gear box output shaft was distorted or damaged looking. No longer square. The channel for the key was badly oval shaped in the pulley and less so in the harder shaft. The pulley was wobbling badly on the shaft which is what probably destroyed the belt.

Obviously the pulley, key and shaft plus seals, etc. are being replaced.

Open for comments. Anyone had this same thing happen?

My question: How can the pulley wobble so badly like it was while mounted on the shaft? Speculation: that it ran long enough with the damaged key to hollow out the pully inside allowing it to wobble?

 

[mikester]

Sorry to hear about your troubles. Do you have any photos?

Usual suspects include bad bearings, broken gears in gearbox.

I've broken spindles before after hitting buried treasures including steel and rocks.

 

[dodge man]

I had a BX bought new about 15 years ago. When I traded it in it had 800 hours of which 500 were mowing. The first deck belt last a few hundred hours then shredded, then two more belts didn’t last very long. The last belt was holding up fine. I wonder if the belts aren’t that great. Could it have had belt problems that caused the damage?

 

[JWR]

Sorry to hear about your troubles. Do you have any photos?

Usual suspects include bad bearings, broken gears in gearbox.

I've broken spindles before after hitting buried treasures including steel and rocks.

No photos of the shaft or the inside of the pulley (the only spots where anything looks abnormal.) The shop has these right now. The output shaft of the gearbox seemed solid/normal smooth and not rocking or wobbly when I got that off the deck. Everything rotates and seems smooth/normal in the gearbox.

 

[JWR]

I had a BX bought new about 15 years ago. When I traded it in it had 800 hours of which 500 were mowing. The first deck belt last a few hundred hours then shredded, then two more belts didn’t last very long. The last belt was holding up fine. I wonder if the belts aren’t that great. Could it have had belt problems that caused the damage?

I suppose the belt may have had issues but it looks more like the belt was the last victim of the incident rather than a cause. I have had Kubota original belts on 2 BX2200's (one over 20 years, 900+ hrs) and 2 on B2150's (one 27 years and one 5 years that I've owned it but probably original and rather old.) Never up to now had a problem with those twin V style kevlar std belts. They seem indestructible, until of course some catastrophe like this happens. Ought to be... a new belt costs over $130 at Messicks.

 

[oldnslo]

I have had a piece of branch get wedged into pulley causing the belt to destroyed. It puts a lot of extra vibration into the belt and pulley but didn’t destroy the pulley. If pulley started to work loose it certainly could have wallowed out the keyway.

Hopefully new pulley and belt is all you need.