3PH finish mower gearbox

[Lockport]

I've a Bobcat 72" 3PH finish mower. I need the blades to turn in the opposite dIrection. I've noticed that on the rear side of the square gearbox is a plastic cap and four bolt taps that would mimic the pattern accommodating the spline shaft on the front. Obviously this I'd just what I'm looking for, but I cannot find a shred of information clarifying the process. How do I do this?

 

[pmsmechanic]

Well there are four bolts holding the top cover on. I'm sure you could take that cover off and you'd be able to see if your idea would work or not.

Even easier would be to take the four bolts out that hold the gear box onto the deck and turn it 180 degrees.

 

[Lockport]

And then what? Knock that plastic piece out and will it let me reuse it on the other side? I could speculate that there is a bearing with a ring clip holding the spline shaft in place and meshing with a 45° angle downward force being applied to another shaft that drives the blades. Removing that and orienting it on the opposing side, turning the gearbox to face forward of course. I suppose opening the top is obviously the next step. Has no one ever seen this before? Thx

 

[Lockport]

That's about what I found. There is a plastic cap on the rear side and a cap on the front with an opening for the spline. Inside the gearbox the spline shaft is thicker and the 45° gear is held in place with a ring clip. My neighbor and I are speculating that there are further ring clips on either end and they both have to come out to free the shaft, remove it, and turn the gear to mesh on the rear side of its facing.

 

[pmsmechanic]

To me it looks like you are on the right track.

So if I understand you correctly you want the input shaft of the gear box facing the same way but the output shaft turning in the opposite direction? If that's true then what you and the neighbor are speculation should work.

 

[bcp]

I've a Bobcat 72" 3PH finish mower. I need the blades to turn in the opposite dIrection.

Won't that unmow your grass?



Bruce

 

[Lockport]

Yeah, we're going in the turf business!

 

[Leejohn]

Just why do you need to turn the blades the other way? Sounds like to me you have the wrong blades are they are upside down. The belt tension pully well have to be changed also.

 

[Lockport]

These mowers aren't made anymore. Whatever Doosan was thinking when they subcontracted these goes right back to the proprietary days of the now defunct Gateway computers. You couldn't buy an off the shelf sound card, video, modem or any other addition because they had a proprietary BUS.

I'm not anticipating any serious complications in the belt tensioner turning in the opposite direction.

 

[Leejohn]

I would be looking for some LH or RH blades.

 

[Lockport]

Gatorblades. I had one on a Snapper, a pair on a Kubota LT, adopted triples on a Kubota BX with reduction adapters and finally found ones that nearly matched the size needed for this cutter. Of the hundred (+/-) Gatorblades that Oregon puts out for a variety of decks, they all have the cutting edge on the same side. If you've never used a Gatorblade, do yourself a favour.

This gearbox is reversible and that's what it will take to make this finish mower cut a proper lawn. I hope to have the only properly functioning Bobcat 3FM72 in existence.

 

[hawkeye08]

Keep us posted, takes lots of photos and make sure you do a proper write up so others can follow it...

 

[Lockport]

Update: There is an oil cap at the back and an oil seal at the front at the base of the spline that cover the bearings. They both have to come out to access the snap rings at each end. My dealer has informed me that there are none in Bobcat's N.A. network and they will have to be ordered at a cost of $85CA and $45CA respectively. Considering a typical oil cap or seal is about $10 or less on eBay, I'm finding this markup to be the abhorrent. Unfortunately, without removing them and rendering the cutter unusable until replaced, I've no other means to determine their exact O.D., I.D, thickness and lip design. I did manage to get a depiction of the gearbox parts diagram and list but it's very poor and getting it was like pulling teeth.

 

[powerscol]

Have you tried Kioti. They are the twin to Bobcat. Also Rino made the loaders for Bobcat, so they may have made the finish mower. If Kioti offered a finish mower on their tractors, I'll bet the parts match. Hope this helps.

 

[Lockport]

These are my new seals. $150CA

In the next couple of days I intend to find the time to pull the original seals from the cutter's gearbox, remove the snap rings behind them and bang out the spindle. Hopefully there will not be any complications flipping the gear over and moving it to the rear side. Will keep y'all posted.

 

[Lockport]

Sorry, no pictures. At the end of the day, street removing the decks, I removed the three snap rings. Then hammered inward from the rear, to free the shaft from its housing, while seperation of the gear is aided by the casement. Everything reversed to reassemble. The inner shim from the forward facing side was reinstalled behind the gear at the rear of the casement. I'm concerned that it is compromising the tolerances as the meshing is now much more audible than before and the box seems to be hotter. That being said, I couldn't help but notice that typically on cutter's the blade bolt has reversed threads. So does this cutter, but I've just reversed the rotation to a typical cutter and bolt rotation is now synchronously with the blade rotation of typical cutters.

 

[Lockport]

I've found what appeared to be identical seals at avxseals.com and they charged $11.02 for both. That's a far cry from the the $110 Bobcat charged me. I'm going to drain out the oil, remove the end cap and the rear snap ring. There are three shims behind it and I'm hoping that by removing two of them the shaft will reseat itself with just slightly less pressure against the facing bevel gear and the audible meshing of the gears will subside. Along with the heat it is generating. If that fails, I'll need to take the entire mechanism apart and find a thinner shim to go over the spline behind the gear that faces the rear most bearing.

That being said, the reward is in the cut produced by the Gatorblades