Help With PTO Shaft Measuring

[TORQUIN]

My old tractor is a 1963 Ford 4000, and my Howse rotary cutter fits it fine. The PTO shaft is too short to even be close to reaching on my new L3830 Kubota.
When I bought the rotary cutter I had to buy a new PTO shaft for it, since it was missing, and I got what I thought was a good size, as it fit my 4000. I did notice it was getting close to the end of the slide in the shaft after I installed new lift arms on my 4000.
I guess I am stuck buying a new shaft now.

Can someone tell me how to measure for a new shaft so I can account for the necessary slide in the shaft? I have no cluse as to what size it orignally came with. /forums/images/graemlins/frown.gif

Thanks,
Chris

 

[MicroPilot]

Here is a link to a bush hog rotary cutter manual that has detailed instructions (with pictures) on how to measure and cut a PTO shaft. Bush Hog Squealer Manual

 

[TORQUIN]

Thanks for the info. It seems like those instructions are "cut to fit". I wasn't aware of cut to fit on PTO shafts. I just assumed that's why they had a slide in them.
But that doc doesn't answer my main question, how do I get the proper (maximum?) measurement to start with? Do I just do a guesstimate at what I believe is the farthest point between the tractor output shaft and the cutter gear box? Then again, figuring the "floating" of the cutter, especially when I am backing into ditches, maybe I want to get a measurement where it must be shortest, so I get a shaft that won't bind, but has plenty of length for when the cuttter gets at a long angle.

Thanks,
Chris

 

[chim]

I've cut three PTO shafts to fit so far. They were all too long to begin with. I measured for the absolute shortest length that would not jam with the arms all the way up, and the toplink at its shortest. Then I deducted a couple inches to play it safe. The shield and shaft needed cut. Both the male and female needed cut. I think I recall cutting about 8" off the last one. It still has lots of telescope left.

I don't know if they are all made this way, but mine only fit together when the pieces were referenced properly. There were three splines in the shaft that are not equally spaced. No big deal....................chim

 

[MadDog]

I have recently done this for a chipper/shredder; so here's what I did. Hook up your attachment to your 3ph and raise the attachment so that the attachment's power input is at the same level (horizontal with) the tractor pto; that will yield the shortest distance. Measure from the notch on the tractor pto to the notch (or shear pin hole) on the attachment shaft. Then measure the same distance on the driveline, with shafts fully overlapped; this distance will be greater. You then take the difference, add 1.5" and that yields the number that you should cut from EACH end of the driveline.

YOu can cut slightly more from the plastic shield over the driveline, but cut at least that amount from it, too.

Whether you use a hacksaw or a sawzall, don't forget to file the burrs from the inside and outside of both parts of the driveline when you are through, and to grease both ends (male and female) before putting the driveline back together.

Hope this helps.

 

[cperky]

</font><font color="blue" class="small">( grease both ends (male and female) before putting the driveline back together.

Hope this helps. )</font>

This is very important . If it ever gets stuck it can be very hard to seperate the two parts. I found out the hard way

 

[TORQUIN]

Thanks for the info. I have gone to the neighbor's house, who has the same cutter I have, and measured his shaft. This will give me another reference. Tomorrow evening I will hook everything up and measure it like you suggested. I will pick up the new shaft Saturday at Agri-Supply. /forums/images/graemlins/smile.gif

Thanks,
Chris