How to measure for a PTO Drive shaft

[NewClimber]

I need to purchase a new driveshaft for a used tiller I purchased. I need to make some mods to the tiller (thanks for the advice on that topic) but want to ensure that I do it right and I can get a drive shaft to will fit. So my question is, from where to where do you measure for a drive shaft. I have found a decent priced one but it says the min is 27". As you can see in this picture I have about 16 inches from tractor to tiller. (another shot Picture 2

Am I measuring this correctly?? I know I need to push the tiller back further but I am trying to decide on how much?? I am thinking about 12 to 14 inches further..

 

[ZJ_HR]

Seems that your justa made case worse with this PTO splines adapter.
Don't push tiller too much backwards, as you'll have problem with sway and "light" front end of tractor.

Here's what I'll do in your case:
- buy a PTO with slip clutch.
- take down that adapter and machined/weld it to central part (disk) of PTO clutch. This idea is from my tiller, which has 40 mm splined shaft on gearbox side (not a standard 1 3/8", neither as yours)
- with mentioned above, you'll save about 4" in length, according to pic #2
- after doing mentioned, I'll measure again, and move 3 pt hitch frame 5-10"forward, as low as possible.
- measure the U-joints angles when tiller is up and down, and then estimate necessary movement

Maybe attached pictures will help you a little with your idea.
I just rebuilt new to me tiller, and if you need more pics, I can help you.

 

[ZJ_HR]

Here you can see a length from end of clutch to U-joint. It's about 5", but that is a big tiller, and cross is 36mm dia, so it will be smaller on yours.

 

[greg_g]

</font><font color="blue" class="small">( So my question is, from where to where do you measure for a drive shaft. I have found a decent priced one but it says the min is 27". )</font>

They're out there, you just have to keep looking. Tillers, fertilizer spreaders, rear PTO driven MMMs all use very short shafts. The one on my Yanmar MMM was only a foot long.

One of the most important steps, is to make sure the implement shaft and tractor spline are at their very closest point of travel before you measure. Failure to do this will result in binding or worse. For one method, check out THIS PAGE. Personally, I prefer to remove the shields and do metal and plastic separately.

That shiny piece seems to be adding three inches, and might be eliminated if you find a shaft into which it's already incorporated. Is that a spline adapter? a slip clutch of some kind, or an over-running clutch?

//greg//

 

[NewClimber]

Sorry for the slow response...The shinny thing is a adaptor...18 splin to 6 splin 1-3/8". It looks like a new PTO shaft is going to run me approx $200. I think by pushing the tiller back about 10" should give me about 12-15" of drive shaft. Hopefully this will be OK...Welding the adaptor directly to the slip clutch is a great idea.. I will have to look into that as well, once I get my brackets welded onto the tiller. I will try to post when I get something resolved...hopefully this will be this year...

 

[ZJ_HR]

</font><font color="blue" class="small">( <font color="blue"> I will have to look into that as well, once I get my brackets welded onto the tiller</font> )</font>
Make a slip clutch before you weld a brackets. It will be far easier.

 

[Pilot]

Looks like a Mitsubishi tiller, which is what I got and it mounts too close to the tractor. As the tiller moves up & down, it exceeds the 15 degree angle limit you are not supposed to exceed.

An option I didn't think of until I had already cut my shaft was to buy longer lower arms for the 3 pt. hitch. Mine were 24", they supposedly sell 32's also.