So, you bought a tractor, have some land and now ready to get the Earth ready for planting. The PTO shaft is a very important piece of equipment for your tractor, as transport power from the tractor to the equipment behind the tractor. Whether you are going to be using a bush hog, a tiller, or any other piece of equipment, your PTO shaft needs to be the correct size.
Parts of your PTO Shaft:
- Internal Yoke
- Universal Joint
- External Yoke
- Safety Chain
- Safety Shield (Always keep in working order AND in place!)
Measuring a PTO Shaft (Always follow the manufacture length recommendations)
In the closed position, meaning the PTO shaft is the smallest it can be, get a measuring tape. Measure from the outside of each side yoke to get the closed length. To see the correct series size with the horsepower of your tractor, use the diagram below. Be sure to know if you have a shear pin implement end, a slip clutch implement end (shown below), or a splined implement end.
Horsepower Rating vs. Series Size
| Metric | USA | HP@540RPM | HP@1000RPM |
|---|---|---|---|
| Series 1 | 6N | 16 HP | 25 HP |
| Series 2 | 12N | 21 HP | 31 HP |
| Series 3 | 30 HP | 47 HP | |
| Series 4 | 14N | 35 HP | 55 HP |
| Series 5 | 47 HP | 74 HP | |
| Series 6 | 35N | 64 HP | 100 HP |
| Series 7 | 44R | 75 HP | 118 HP |
| Series 8 | 55N | 95 HP | 150 HP |
Measuring the Universal Joint:
To measure the universal joint, using a tape measure, measure the width from the outside to the outside (B). After getting that measurement, measure the width of one end of the universal joint (A). After getting that measurement, use this diagram to find the correct size universal joint.
| ASC Part Number | Eurocardan Part Number | Series Size | Description | Cap Diameter A | Cross Height B |
|---|---|---|---|---|---|
| 31369 | 1001020 | 1 | Cross Kit Complete | 22mm / 55/64" | 54mm / 2 1/8" |
| 32190 | 1002020 | 2 | Cross Kit Complete | 23.8mm / 15/16" | 61.3mm / 2 13/32" |
| 32191 | 1003020 | 3 | Cross Kit Complete | 27mm / 1 1/16" | 70mm / 2 3/4" |
| 31370 | 1004020 | 4 | Cross Kit Complete | 27mm / 1 1/16" | 74.6mm / 2 15/16" |
| 31371 | 1005020 | 5 | Cross Kit Complete | 30.2mm / 1 3/16" | 80mm / 3 9/64" |
| 32192 | 1006020 | 6 | Cross Kit Complete | 30.2mm / 1 3/16" | 92mm / 3 5/8" |
| 32193 | 1007020 | 7 | Cross Kit Complete | 35mm / 1 3/8" | 94mm / 3 45/64" |
| 32194 | 1008020 | 8 | Cross Kit Complete | 35mm / 1 3/8" | 106.5mm / 4 13/64" |
| 75443 | 1000020 | 10 | Cross Kit Complete | 41mm | 118mm / 4 41/64" |
Check out our PTO Shafts and Accessories categories for a complete listing.
