Bx2350 is this shaft bent?

[B737]

Embarrassment forthcoming.
I’m an idiot. Pulled the entire thing apart. Lifted the motor. Changed the stupid hst fan. Put it all back together, forgetting I had a pair of vice grips on the shaft. I bumped the starter and realized my mistake. I did not run it prior to disassembly, so I’m not sure if it was like this. But I think this shaft is bent.

If you guys think this is bent should I also order new CVs?


https://youtu.be/QV4UC-YxGa0

 

[dlsmith]

Sure looks bent to me.

Oops.

Depends what condition the CV's are in. Clean them up and look them over closely. If they show any wear, I'd replace them.

Don't feel to bad, we all do stupid things occasionally, I know I do.

 

[B737]

I agree, it looks bent right where i had the vice grips. now i get to do all this again. i'll order a new shaft and CVs... so mad at myself. was literally the last thing...


Untitled by K. L., on Flickr

 

[Fordtech86]

I can’t see a pair of vice grips bending that shaft. It’s hard to tell what’s going on in your video. Do you have a vibration while it’s running? From what I could tell it was running at a high rpm then cut down? Cv joints will have that effect when speeding up and slowing down. If it isn’t vibrating or making noise I’m sure it’s fine.

 

[B737]

the ends of the shaft where it goes into HST and crank at engine look smooth, but it shakes like hell in the middle esp during idle, you can see towards the end of the video when i slow the rpm down how much it starts shaking. The vice grips were already against the frame as a stop so its not like they went "slap!", the starter literally only bumped, prob not even a full turn and i realized it, it didnt fire just cranked.

 

[Fordtech86]

I see what your talking about but do you feel it in the tractor? It’s a tri lobe design and things moving around during run up and decel, that’s a long shaft too from what it appears. Probably why they have a cv joint set up then a straight shaft or u joint set up.

 

[Pau7220]

Something is definitely going on there. Any machine shop that does engine work should be able to straighten it. Almost all do crankshaft straightening.

 

[B737]

Alright thanks guys. New shaft is only $60 so I’ll order one and maybe new CVs
So frustrating cause I was one step away from this being all done and cracking a beer after all that work

 

[Fordtech86]

What is the yellow/black thing you have the square on? I’m not a tractor expert but have done lots of nvh concerns on things that go way faster. What I seen at a constant speed looked ok, on accell or decell angles change between the components.

 

[North Idaho Wolfman]

But I think this shaft is bent.

If you guys think this is bent should I also order new CVs?

Stop thinking... the shaft is FUBAR, the CV's are fine, reuse them.

 

[Lil Foot]

Stop thinking... the shaft is FUBAR, the CV's are fine, reuse them.

I agree.
I personally would straighten the shaft, but I used to do that sort of thing as part of my job. Without years of experience and the proper tools, it would be a nightmare, so take the easy, sensible way out and buy a new shaft.

 

[B737]

Thanks guys. New shaft ordered. I got it all back together put my hand on the key and said “that wasn’t really all that bad”, then “oh #%#”. A $60 mistake, but a real blow to the ego after completing all that work.

On the old machines instead of there being 3 bolts on the 2nd coupling at the crank there is only ONE. There is zero room to move that shaft without moving the entire motor. I’ll update once I get the new shaft in. Gonna be a week before it even ships. Ughhhh

 

[Wbk]

That's a big oops, while your at it you might want to replace the fan belt.

 

[B737]

Just an update on this self induced issue and some photos for anyone taking on drive shaft rebuild.

I recreated the scene of the accident. You can see how easily the shaft was bent, even though the vice grips didnt swing when I bumped the starter, they acted like a cam and rolled the shaft, done deal. Im thankful I didnt get hurt, damage the motor, or hydraulic lines. I had just gotten back from work, hadnt slept in about 30 hours, should have called it halfway through and started fresh the next day.

New shaft should be here next week, I will update this thread with reassembly.

Untitled by K. L., on Flickr

Onward...

to remove the shaft, lift motor...
the only way i could see to get it out was disassembling the front CV while hanging down, then lift the shaft up out the top. I dont think it would have come out the bottom even if i removed the rear CV because of the angle and size of the forward flange hitting the metal frame cross brace.


Untitled by K. L., on Flickr

I have never seen dampers in CVs before so i wanted to capture this. 7 out of the 8 dampers in the CV were broken. here you can see how the damper sits on the bottom of the ball like a seat in the CV. The inner races are oriented to locate the bearings closer to the middle of the shaft.

Untitled by K. L., on Flickr


Untitled by K. L., on Flickr

this is the order of the front CV, you will notice the balls are oriented more towards the middle of the shaft, dont put the race on backwards.

Untitled by K. L., on Flickr

one, very bent shaft.

 

[North Idaho Wolfman]

The dampeners on the balls is a new one by me too, I'll admit I haven't taken many of these new ones apart.

So from what your seeing does it look like the joints are damaged?

 

[B737]

The splines and the CVs appear to be ok, with the exception of the dampers which were prob just old. I think, and hope, the shaft took the brunt of it.

waiting on the new shaft to arrive.

 

[B737]

Wanted to thank you guys for the reality check. Everything is all back together. Pulling the engine on the old BXs is really pretty simple, maybe an 35 minutes to pull the foot deck, fender, and hood off, then 4 engine bolts, 4 radiator bolts, the 2 ground points, and the whole thing is moved well out of the way.

I assembled the new rear CV joint on the bench, but there is not enough room to do this for the front side. I only attached the inner race to the front, passed the shaft through to the front and under from the top. Then assembled the rest of the forward CV joint from underneath the tractor I had a helper on the top side steadying the shaft for me. It wasnt too bad. New shaft didnt come painted, i didnt paint it. Machine runs well, hey new HST fan lol and nice and clean. Just waiting on bxpanded under armor before putting it to work in the woods. It's too bad Kubota didnt use a 2 piece drive shaft, or a modular (not home made) fan.

The old fan belt was in really bad shape so that got replaced. Used the opportunity to do a lot of cleaning, and replacing of old, worn out or broken stuff that I found along the way.

this community is a wonderful resource, so much information here, and lots of videos on youtube to help along the way.


Untitled by K. L., on Flickr