Tractor PTO Coupling Issue

[bigbendmarine]

Operated tractors for years, but can't say I talk parts often so beg forgiveness in advance for any poor terminology... that out of the way, while mowing this weekend (John Deere 5425 pulling a MX10 mower) I had the U-Joint connector slip off the connection fitting at the end of the telescoping shaft. In case my words are poor, happened at juncture circled in red on first picture below.



Here's two pictures of the disconnected ends... this one showing the fitting end of the telescoping shaft...



Next picture showing U-joint fitting...



By loosening the fitting bolt and using a strong screwdriver to pry it ever so slightly I was able to slip the fittings together. Did my best to hand tighten them enough to hold, but probably didn't make it 100 yards before they disconnected again and for anyone who's experienced it happening can't say I really want to keep having the U-Joint portion of the arm wildly flapping around again while I race to disengage the PTO.

So here's my question... anyone had this happen, and if so how much force needs to be applied to the fitting to get it to hold? Should I be able to hand tighten with hand wrenches or is it going to require heavier torque? And / or am I totally overlooking some other locking mechanism that helps hold them together beside tightening the clamp bolt?

Again, asking in hopes I can fix myself without repeats of it coming apart again any time soon. ALL wisdom / insight shared will be MUCH appreciated!

 

[Tap]

I have no idea but here's a thought...is it possible that the bolt has some stripped threads and it can't actually stay tightened? Have you removed the nut and examined the bolt threads?

 

[yoderjac]

Have no experience with these particular models, but the other thing I'd check in addition to what Tap said is the PTO shaft. It should slide easily in and out as the vertical angle between the tractor and mower changes as you go over terrain. If the PTO shaft is rusted shut or stuck or something so it does not slide in and out, terrain could cause the u-joint connection to the gear box to be pulled.

Thanks,

Jack

 

[mikmaze]

can't see one on that pic, but most of the time, there is a detent that the bolt aligns with, kind of like in the quick release end at the tractor so it stays retained even if the bolt gets a bit loose. splined female would have to line up correctly for this to work correctly when you looki into the piece in your left hand in second pic, does the shaft of the bolt show? take the bolt out, does it have a groove worn in the side of the bolt.? is the slip joint greased on the section to the left of your red circle in first pic? that is where it should slip, nice and easy so it does not try to pull off where it is. not sure how well worded this all is. lastly, try swapping out the bolt with a grade 8, torque it down as a graded bolt will hold more force, and then double nut it so it cant back out. another thought, take that green cover off and inspect what lies behind the cover held on with pin in second pic. Looks like so little splined shaft is showing, seems like there may be a collar on the shaft that could be removed to allow deeper connection between male and female splines. these are all make it work better ideas, stuff I would try.

 

[Jim Timber]

My inclination is to say the long rear shaft section isn't fully presented out of the bearing housing you're trying to attach to. The nub of the male spline isn't long enough, and if you pulled it forward about 3" you would see the groove that the bolt you're tightening is supposed to ride in on that male shaft.

The bolt does clamp the female to the male on this design, but it's supposed to be an interference connection with a groove in the male stub and the bolt must be removed first to connect them properly.

 

[Jim Timber]

Here ya go:

Per the instructions, that shaft may be pressed into the bearing and that may be why you aren't seeing the groove if it's worked out or wasn't assembled correctly in the first place.

http://manuals.deere.com/omview/OMW45015_19/AG_OUMX005_818_19_03JUN99_1.htm

 

[mikmaze]

^ exactly, seems like something isn't right.

 

[Redonthehead]

What Jim T said, or is the end of the male shaft broken off at the groove? - perhaps still inside the female end above the bolt?

 

[bigbendmarine]

Sorry for not responding sooner -- can't remember the last time I had much more than a cold, but SIL came down to visit us and one of her rugrats gifted our whole family with 24 hour stomach bug. My daughter fared the worse throwing up 30 times in a 24 hour period before it passed. Thankfully we're all starting to feel human again.

If talking the groove in the male shaft I have circled below, the good news is that it isn't broken. Just retracted in the picture I took. Think it may be a combination of the telescoping shaft being a bit sticky (I can manually move it, but not super smooth and easy) as well as bolt issue, as when I looked down at the bolt when trying to get it back together the first time it had vertical runs in it that matched the path of the male shaft end... guess over time it gut tugged often / hard enough it worked the pattern through the bolt so that it no longer had interference.

Probably be the weekend before I can look at it closely again, but MUCH appreciate AL:L the words of wisdom!

 

[Jim Timber]

Might want to check the straightness of the long PTO shafting. When I twisted my second stump grinder PTO shaft, it was only tweaked just enough to bind up and not slide but wasn't so visibly damaged as to look bent.

Take it all the way apart and look for shiny spots where it's got firm contact. If it doesn't have anything glaringly obvious and passes the eyeball straightness test, then you should take a wire wheel to it and clean any rust off then grease it up good when you reassemble it.

I hope you guys are on the mend quick! Being sick sucks.