Grasshopper 623T with 52" PowerFold Deck; high pitch noise

[logsdonj]

Over the weekend, I had a noise come up that can be heard in this video I made.

The mower has around 50 hours on it.

The video starts at 1/2 throttle with the high pitch noise, I increase to full throttle, then bring it back down to idle by 15 seconds before disengaging the PTO at 27 seconds.

I increased and decreased belt tension an inch this way and that with no audible effect to noise. I know the manual says to only have 5.75" for the spring expansion, but it had about 6.5" when I took the cover off... again, only 50 hours on the mower, so that's how it came and I'm not sure how else to check what tension should be. I slacked the spring to 5.75" now but it's near the end of spring bolt and I don't know if that's enough.

I check the larger idler pulleys in this video:

There doesn't seem to be any large play in them. The one on video right/driver left had a little bit of a whir to it when spinning freely, but I had to put my ear close to it and it still spins well. The bolt holding it on was loose when I first checked everything... I only noticed when trying to tighten bolts.

The spindles and blades seemed tight without play. When spinning the middle blade, some small noise can be heard inside the spindle housing at different rotations, but the same with driver right one also, but I did not have time to take off blades and spindle housing to inspect. It could have even been some debris rubbing against the spindle housing during rotation that I didn't see.

Before digging more, I'm hoping it will sound more obvious to someone with more experience. The mower is at family's place that's a 3 hour round trip, so I'm not able to check more quickly. Thanks!

 

[logsdonj]

I'm giving up and taking it into to the shop tomorrow. They are scheduled about a week out, but I plan to reply back on what became of everything.

 

[logsdonj]

It turned out to be a gearbox issue and needed replacement.

 

[gsim]

Was going to tell you check level of gear oil. in gearbox. WARNING. I ordered and installed a new gearbox on my 930D. (around $250 on eBay) When I took it out of the box, I laid it on my work bench and checked oil level. Thing was only 2/3 full. Supposed to have oil enough to reach overflow port. I topped off with 80W130 gear oil.

 

[logsdonj]

Thank you for the reply! I just picked up the mower and deck today. They replaced the gearbox and I got the old gearbox so I could learn from it (they are new territory for me). They said it was leaking oil and such and the bearings were rough. I plan on taking the old gearbox apart in the future so I'm more comfortable. I'm not sure if they checked the oil level, but it was at a Grasshopper dealer/agriculture shop, so I'm hoping I didn't have to

From what I understand, in its upright position, the top hex bolts are the fill holes and full is up to their threads, right?
Do you have a certain amount of hours usage that you think is best to check it?

I think the manual went into some text details on removing the gearbox (take deck off mower, remove guard, take out half shaft, etc.), but I'll have to YouTube around for some visuals to get my confidence up.

 

[gsim]

Thank you for the reply! I just picked up the mower and deck today. They replaced the gearbox and I got the old gearbox so I could learn from it (they are new territory for me). They said it was leaking oil and such and the bearings were rough. I plan on taking the old gearbox apart in the future so I'm more comfortable. I'm not sure if they checked the oil level, but it was at a Grasshopper dealer/agriculture shop, so I'm hoping I didn't have to

From what I understand, in its upright position, the top hex bolts are the fill holes and full is up to their threads, right?
Do you have a certain amount of hours usage that you think is best to check it?

I think the manual went into some text details on removing the gearbox (take deck off mower, remove guard, take out half shaft, etc.), but I'll have to YouTube around for some visuals to get my confidence up.

Roger. Removal would be to loosen belt, raise deck, remove stumprrock gaurd. Unt bolts to it, and is also surrounded by it to prevent damage. ONly thing holding it will be sheave above it in deck housing. Lower deck and loosen the two collar set screws that lock the sheave collar to the vertical gear shaft. Unit should fall to floor. Raise dec,, pull unit off of stup shaft spline. On my mower, sheave rusted, stuck to shaft. sledgehammer never broke it loose. So I had to take gearbox housing apart beneath deck, let the two halves fall to floor along with the horizontal (input) shat. Only thing reaining was the vertical shaft, stuck in the collar of the sheave. Nice big hole under the sheave, so easy to pull whole thing out from top. Ended up using my 20 ton press and acetylene torch to heat collar so as to press old shaft out. My 20 ton press would not press it out until I applied heat to collar of sheave. Surprised me, really because that sheave is NOT a press fit unit. Needs square key and both locking screws to be properly tightened. Live and learn.