Dropped my MFWD drive shaft

[AceDeuce]

So I'm going along and I suddenly hear a klunking sound coming from underneath the tractor. I stop, get off and look underneath. I find the front drive shaft dangling---this is new... The 1/4" X 1-1/2" roll pin that holds the universal joint to the shaft coming from the HST sheared off. I was able to remove the piece in the yoke but there is still a piece lodged in the drive shaft that I wasn't able to push out---need a different tool--- and a couple more elbows to reach up under there. It'll be fixed after a run to the hardware store.

The big question is... why? That roll pin should not have been taking any load. It is a splined shaft connection, so there should not be any torsional stress on the pin, and the other side of the universal joint has a telescoping splined shaft connection so there should not be any axial stress or moment on the u-joint. I can't imagine how the pin broke. Sorry for not posting any pics but it looks like fatigue cracking on both sides of the pin as it passes through the splined area between the shaft and the yoke. That would indicate play in the shaft but I couldn't feel any.

Anyone else had this problem? Should I replace it with another roll pin or something else? Not a big problem by any means but a pain in the neck (literally) nevertheless.

 

[art]

Is the shaft dry?
Does it show that the splines are showing wear on the couplers as well as on the shaft?
How has it been shifting in and out of four wheel drive?

 

[mozark]

Don't know if this is your problem or not, but I seem to remember a similar problem someone posted, I think it was with a BX2200. Seems like they thought it was caused by looseness/wear to the front axle pivot pin. You might check that, or see if you can find that post.

 

[jesseb3@att.net]

Same thing happened to my friend's BX2230. He reassembled it himself with a new roll pin, and it didn't sound quite right after that.

He took it to the dealer, and they said that he didn't reassemble the driveline properly... that it needed to be re-aligned a specific way(?) Didn't make sense to either one of us.

Maybe I'll call him to see if he ever figured it out...

Jesse

 

[aggiehortguy91]

I had that happen to my BX2200 a while back. I think the roll pin is a 6 mm, but can't remember for sure. I had to take it apart and the local Kubota dealer was able to knock it out for me and give me a new pin. You will have to use the proper size metric pin drift, I distroyed (and even got one stuck!) several standard drifts. That roll pin didn't want to move.

As to why it broke, I have no idea. The pin shouldn't take any real torque since it is holding together 2 splines. I ended up using a small bolt to put it back together and everything seems to be fine. I do need to crawl under there and have a look at it since that has been about 100 hrs ago.

 

[AceDeuce]

Thanks for the feedback. I noticed the lower u-joint was secured using a solid pin so I decided to replace the upper u-joint with a solid pin instead of a roll pin. That way if it fails again it will at least be easier to replace.

I made sure the driveline was reassembled correctly and I lubed the splines just to be sure there is no binding. Hopefully it will hold for a while.

 

[edgerg2012]

Thanks for the feedback. I noticed the lower u-joint was secured using a solid pin so I decided to replace the upper u-joint with a solid pin instead of a roll pin. That way if it fails again it will at least be easier to replace.

I made sure the driveline was reassembled correctly and I lubed the splines just to be sure there is no binding. Hopefully it will hold for a while.

What size roll pin and is your tractor mahindra 2015 HST?

 

[ruffdog]

Same thing happened to my friend's BX2230. He reassembled it himself with a new roll pin, and it didn't sound quite right after that.

He took it to the dealer, and they said that he didn't reassemble the driveline properly... that it needed to be re-aligned a specific way(?) Didn't make sense to either one of us.

Maybe I'll call him to see if he ever figured it out...

Jesse

Maybe the driveshaft u-joints were not "in phase".

 

[nyone]

Same thing happened to my friend's BX2230. He reassembled it himself with a new roll pin, and it didn't sound quite right after that.

He took it to the dealer, and they said that he didn't reassemble the driveline properly... that it needed to be re-aligned a specific way(?) Didn't make sense to either one of us.

Maybe I'll call him to see if he ever figured it out...

Jesse

They mat have been talking about the drive shaft being in/out of phase. Generaly you want the yokes on the shaft portion to be inline with each other. How ever for a slow speed shaft like I think these are it may really not matter.

When I got my b8200 I did the clutch and also noticed the dry splines on the driveshaft connection. It also uses a roll pin that was nearly half broken along with a well worn U joint. These pins where held in with a piece of wire running through them from the factory I believe. Yes they suck to remove after 30yrs.

 

[Fallon]