What length PTO driveshaft

Pooh_Bear · May 23, 2011

I need to buy a new PTO shaft for my finish mower.
8N tractor, 60 inch finish mower.
I have to make up the difference in length for a HF QH.
Currently the overall length is 44 inches and the length
from U joint to U joint is ~38 inches.
It's one of those triangular tube shafts.
Unless I can beat the price somewhere else I plan
on getting this at Northern Tool.
I would have to cut this one to length.

Mine would work if it wasn't frozen in place.
I think the one I linked to above will work for me but
I want to make sure. Advice and comments welcome.

Thanks.

Pooh Bear

wrooster · May 23, 2011

YouTube - ‪How to Measure and Cut a Tractor PTO Shaft‬‏

Regards,
Wrooster

Pooh_Bear · May 23, 2011

That was very informative. Thanks.

Pooh Bear

Eric_Phillips · May 24, 2011

Pooh_Bear said:
Mine would work if it wasn't frozen in place.
I think the one I linked to above will work for me but
I want to make sure. Advice and comments welcome.

Thanks.

Pooh Bear

What do you mean by "frozen in place?" Is the shaft rusty and does not telescope anymore? I had a very nasty shaft that was on a manure spreader left in the weeds for 10-15 years. I pulled the shaft off with the u-joints on each end. I tied one end to a fence post and the other end I connected a come-a-long which was tied to another fence post. With some PB blaster and about 2-3 hours of tension on it it came loose. A wire wheel to clean up the rust and it works great now. I am not the originator of this technique, I got it from someone else on this forum.

Pooh_Bear · May 24, 2011

Yes, it is frozen and won't telescope. I posted about it on another thread. I'll try to unfreeze it after I get another one. Then I can cut it to length and use it on my brush hog since its shaft will be way too short with the quick hitch.

Pooh Bear

ModMech · May 28, 2011

The INSTALLED PTO shaft should provide the following:

1/3 tube length overlap of the inner and outer tubes, more overlap is generally better, less is BAD.

So, if your tube is ~36" weld to weld as operating....

12" free on the inner
12" overlap
12" free on the outer
= 36" total (operating) tube length.

More overlap provides less vibration and wear, but can make installation to the tractor difficult on short shafts. Less overlap generally results in increased wear and vibration but easier installation or use on multiple impliments.

To confuse this even more, the example above means that each shaft (inner and outer) is 24" long when measured seperately.
]===========############------------[
{..........24"............................}
_____________{............24"......................}