BX drive shaft boot--non-propeller end

[JackJ]

Three years ownership of by BX1870 and I just had my first breakdown. I was mowing and looked down to see 0 on my tach, and the digital dash dead as well. Didn't notice any other symptoms, so I finished the 5 mins of mowing I had left. Then when heading up the hill back to the garage, the power dropped significantly to the point where it almost stalled. That got me concerned.

My first check was the fuses, and sure enough one 15A was blown. Upon replacing it the dash came back to life, so I started it up again, and the dash died immediately. Was still running fine, but now that my hearing protection was off, I noticed a very slight flapping sound that I couldn't detect before.

In crawling underneath I found what you see in the attached image. The rubber boot on the engine side of the driveshaft somehow shredded, and as it was flapping around it severed the wires leading to the lift pump, leading to short and the blown fuse. The good news is that the power loss was almost certainly caused by the pump being out of commission.

The bad news is that the pump wiring appears to be part of the main wiring harness, which if I've looked it up correctly, Messick's charges $462.42 for. But I can splice in wire to do an effective repair, so I'll take that route.

The other bad news is that to get a replacement boot on, I've got to remove the driveshaft. I've read about doing that on the propeller/hst end. Is it any easier on the end I'm dealing with, given that I only need to create a small gap? I haven't studied the components yet, but if get it unbolted, is there any play such that I can slide a new boot over the end?

If it's not that simple, I might want to take it to the dealer. But this time of year I'm afraid it may take them a while, and the cost estimates I've heard for dealer fan replacement were significant.

Any help will be greatly appreciated.

 

[JackJ]

Answering my own question here, but for future reference for anyone dealing with the same issue: This morning I was able to remove the drive shaft and all the coupling pieces on the engine side. I did it from underneath and the process just involves the three bolts on each of the two coupling connectors, an internal retaining ring that I got out with regular needle nose pliers, and a split ring on the very end of the shaft.

Getting that split ring off the shaft was a bear, but everything else was pretty simple. I noticed some of the damper rings that sit inside the balls on the inner coupling were damaged, so I'm replacing those along with the torn boot. Total parts cost was less than $5, apart from shipping, so well worth my time.

Since folks doing the more common fan replacement also need to undo this end of the drive shaft, I found all the info/images I needed on youtube videos dealing with the HST fan.

Parts are on order and I should be back in business by the weekend.

 

[jetattblue]

Well done! I am guessing that you just saved a good deal of money taking it in for a repair.

 

[D2Cat]

And time. But also understands the working parts of the tractor better!

 

[NorCalOrange]

And time. But also understands the working parts of the tractor better!

This is very true! Split the tractor recently and have a lot better understanding of how it works and all the components. Its too easy to jump in the seat and not appreciate, and respect, whats going on to make it function.

 

[JackJ]

Well there's still plenty of time for me to screw something up upon reassembly! But yeah: very glad I didn't have the dealer come pick it up. Some of the HST fan replacement techniques involve unbolting the motor from the frame, removing the radiator, or taking out the floor pan. That stuff sounded intimidating, but my issue turned out to be much simpler. The folks who have documented the procedures on YouTube have taken all the mystery out of it, which is great for someone as inexperienced as I am.

And I do have a better understanding of some of the electrical and mechanical components. But also a question. It looks like all the torque of the engine is transferred to the drive shaft through 4 steel balls, which I'm guessing are about 3/8" in diameter. I can see how that allows some necessary play, but I'm surprised how small the contact area is for getting the power to the transmission. Or am I missing something? I'm talking about parts 050 in the attached image. One thing that's clear is that parts 060, the "ring dampers" don't last all that long, but I don't recall anyone have significant issues with these shaft couplings--they seem to work just fine.

 

[1ruralmailman]

that is true all the power to the tractor from the motor gores through those three ball bearings.its why when those boots get damaged they eat those housings up quick.i didnt find mine as quick and had to do both ends with the housings.it cost me close to 400.00 with me doing the work.but i did understand the tractor better,and made sure those boots got looked at once every few months after that.