BX2360 - Broken HST Fan - Thinking about putting a rigid coupling on the shaft

[CasualObserver]

So have a BX2360 here. Broken HST Fan which is not that unusual.

I drilled a 1.5" hole above the fan to easily access the bolt that hold the rear coupling on the tranny side. That allowed me to remove the bolt in under 5 minutes easy as pie. I installed a metal cover which friction fits the hole perfectly.

Going to slide the engine forward with a hoist I borrowed from a friend. Would prefer not to buy yet another 150+ pound chunk of metal for a one or two time time use if this happens again.

I saw in another thread here or on orangetractor that someone suggested possibly cutting the shaft when it was off and fitting it with a rigid two piece coupling. Idea is that in the future if the fan should be hit again the coupling can be removed and the rear portion of the shaft easily removed without messing with the engine side at all.

Looking at the specifications for the coupling at Mcmaster for the following part:

McMaster-Carr

Image of the coupling:



I measured the shaft as 20mm.

Specifications from the site:
Material: Steel
For Shaft Diameter: 20mm ï¾— 20mm
Overall Length: 65mm
OD: 42mm
Maximum Speed: 4,000 rpm
Maximum Torque: 3,095 in.-lbs.
For Shaft Type: Round ï¾— Round
For Shaft Misalignment Type: None
For Motion Type: Forward/Reverse, Start/Stop, Continuous

When I looked into the details of the engine torque for the BX2360 I found max torque of 44 foot-pounds which converts to 528 inch-pounds. Since the part is rated at 3095 inch-pounds it should be able to handle the torque fine.

Link to Torque chart for the Kubota D902 engine:
DieselEngineMotor.Com - Kubota Diesel Engine D92

Part is available for $56 plus tax delivered.

So what are your thoughts on this? Are my torque figures wrong? Am I crazy to even think about doing this? Please give me your feedback negative or positive.

Thanks!

 

[Tractor Seabee]

I have thought a lot about this and have also come up with the coupling idea. First time replaced by the dealer shop along with a lot of casualty work that had it in their shop. Couple years ago I was in the throes of a major move and had my favorite mechanic do it for me. I did not have time to watch him. I gave him a copy of a post where the OP had pulled the shaft enddo to get the rear coupling disengaged from the shaft spline. He said that did not work, not enough end play even compressing both thrust springs (there is one in each coupling housing). He resorted to the standard process in the WSM of moving the engine. After getting all the sheetmetal, out of the way he had 2 hours getting it apart and back together and engine remounted. The fan replacement was less than 5 minute of that. Add 2 hours to remove and replace sheetmetal.

Having read various threads on this subject and perused the NSM and parts manuals; several ides have cropped into my head:

1. Skid plates
2. Install the coupling as this post postulated; not sure there is enough flex to get one end by the coupling assembly, may need two, increasing shaft flex and balance.
3. Devise a 12 volt squirrel cage boat bilge fan to replace the shaft fan.
4. Devise a an oil cooler system to cool the oil externally with a tranny cooler and fan fabrication.
5. Devise two piece fan assembly; cut a fan in half, drill 2 more holes, make a two 2 piece thin steel plates matching holes on the coupling, drill holes to match the fan and tap for 1/4 bolts. Install he plates offset of the cuts. Looks like the fan bolts can be accessed (not easily) from underneath

Numbers 1 and 3-5 have been done by various posters, 2 is the OPs unproven idea. 5 is my unproven pet idea.

I developed a set of pros and cons for each idea to evaluate.

1. Pros= Almost fool proof protecting the fan (nothing really is).
Cons= Expensive, of of extra time accessing maintenance items; trash collector,
Note= As BXs have no HST temp gauge; does the skid plate restrict air enough to keep HST warmer than it should? Has anyone really evaluated this?

2. Pros= Simplifies the effort and time to change a fan; most ancillary part removal for access is eliminated
Cons= Still much time and effort required to separate the shaft, replace fan, and replace; expensive machine shop work to cut,shaft, prep coupling and shaft, align, and balance.; there is just barely enough room between shaft and floor panel. I have used shaft couplings and they fit fairly loose (we often had to put a pillow block on each side to maintain alignment (impossible here); considered that probably would need to be a splined connection. Either way, corrosion prevention is a must.

3. Pros= Gets rid of a maintenance nightmare
Cons= Where do you put it and keep it out of the way; bulky, another thing to maintain; expense for materials ("marine" label jumps price); find the right pieces to assemble; as much or more vulnerable to damage.

4. Pros= Same as 3
Cons= Same as 3

5. Pros= Simplifies replacement of fan, especially if it can be done from underneath (have to peruse this some more); gets replacement down to a $12 item; big money saver over time.

I lean toward #5. It is something can do in my shop, all I need is my drill press and hand tools. I will have mine in the shop later this winter (have to make the room for it). I will order the new fan and start evaluating making those discs. First will review the space and access. Plan to sandwich the plastic between them and stack drilling for alignment. I will have the floor plan off anyway for other minor work like replacing the fuel tank.

When I get started will keep you all posted on progress, think Feb/Mar. I think now regardless of access I will still do the 2 piece fan idea; its cheap and no matter what, still will save a lot future time and drama.

Ron

 

[BX23S-1]

How did you break the HST fan (???)
BXpanded makes a belly guard to protect the fan.
Seems it would be cheaper (to me anyways) to buy the BX guard and never have to replace the fan again if debris is a problem.

Here`s the link if you want to check it out
BXpanded Under Armor

 

[Tractor Seabee]

How did you break the HST fan (???)
BXpanded makes a belly guard to protect the fan.
Seems it would be cheaper (to me anyways) to buy the BX guard and never have to replace the fan again if debris is a problem.

Here`s the link if you want to check it out
BXpanded Under Armor

Did you read my whole post? I considered that solution. I am not a fan of the skid plates for the reasons stated. The potential air flow problem was brought up by my dealer shop foreman. Their evaluation was that part. They never have one on heavy load long enough to tell. Has BXpanded made that evaluation under typical field work? My dealer, when you take your tractor to them they ask if you have the skid plates. They charge extra if they have to remove them to do their work. They hate messing with them.

Ron

 

[SirMaxwell]

The skid plate comes off in a couple mins.

 

[CasualObserver]

Thanks well thought out reply Ron. I have seen most of your ideas in different posts by different people - many creative ways to address this out there.

Saw one person add external hydraulic cooler for the HST. It involved moving the lines from the filter location to a spot he placed it up by the ROPS. Major work in fabricating the lines etc. Looked beautiful when he finished it and cooled the system much better than the stock fan if I remember correctly. Out of the scope of work I would want to do though.

Squirrel fan I tossed out due to space issues and the other cons you mentioned.

Skid plates - possible cooling issues and not guaranteed since nothing is.

Two piece fan...I saw mention on one forum where a person fabricated a metal fan which I believe was two pieces. Never found the original post - would love to see it since I think there were pictures of it. I believe the fan bolts on from the transmission side - hence can not get to those until the shaft is slid forward. Wonder how that would affect what you are considering. Would love to see this finished if you can get it to work.



For the coupler I was looking at the clearance to separate them in the future...hopefully enough there - will be tight. I figured worse case is I have to spend another $75 for a new shaft if it doesn't work out. Never dealt with couplers - reason I am asking here in the first place. The one I linked uses eight bolts to tighten it down, supposed to have solid tight friction clamping. Appears to be the best one of the various couplers I have found for higher torque and RPM ratings and I trust McMaster to be accurate about those. Not sure how that would be loose when mounted like you mention you have seen in the past. I figured that would be an issue with ones that only used set screws to hold them in place.

Thanks for your reply!

 

[CasualObserver]

How did you break the HST fan (???)
BXpanded makes a belly guard to protect the fan.
Seems it would be cheaper (to me anyways) to buy the BX guard and never have to replace the fan again if debris is a problem.

Here`s the link if you want to check it out
BXpanded Under Armor

Making some assumptions there. I didn't break the HST fan is the first one. If you spend some time looking at the forums you will find a long list of people that have broken the HST fan. I have seen the skid plates. Know that is an option. Asking feedback on something different in this post. Thanks for your time.

 

[BX23S-1]

Did you read my whole post? I considered that solution. I am not a fan of the skid plates for the reasons stated. The potential air flow problem was brought up by my dealer shop foreman. Their evaluation was that part. They never have one on heavy load long enough to tell. Has BXpanded made that evaluation under typical field work? My dealer, when you take your tractor to them they ask if you have the skid plates. They charge extra if they have to remove them to do their work. They hate messing with them.

Ron

Yes Ron, i read it, but i was writing what i said before i saw yours posted. When i hit the reply button, thats when i noticed you had posted yours.
Yours wasn`t there when i started to write my reply. Anyways, not a problem, i get what your saying. I was curious how people break these fans, i`ve never broken one.

 

[CasualObserver]

Yes Ron, i read it, but i was writing what i said before i saw yours posted. When i hit the reply button, thats when i noticed you had posted yours.
Yours wasn`t there when i started to write my reply. Anyways, not a problem, i get what your saying. I was curious how people break these fans, i`ve never broken one.

Normal way people break these fans is running over a stick. Or driving through brush of any type. One stick / twig / branch / sapling the size of your small finger gets into the fan and it is over in a heart beat.

 

[wild bill]

4. Devise a an oil cooler system to cool the oil externally with a tranny cooler and fan fabrication.

For anyone that did not see the original thread, here is a link to it.
https://www.tractorbynet.com/forums/kubota-owning-operating/212864-bx25-transmission-filter-relocation-cooler.html