How do you choose the right model when replacing a PTO shaft?
Despite good maintenance, top quality materials and innovative technology, there will come a time that you need to replace your PTO shaft. After all, safety and efficiency are serious priorities in your work! Power take-off shafts for agricultural machinery and tractors come in various sizes and models: how do you know which PTO shaft you need? Just follow this step-by-step plan to make the right choice.
Step 1 – Check the cover of the current model
Check the cover of your current PTO shaft. Manufacturers often detail the size and model on the cover around the PTO shaft. If you’re lucky, you won’t have to try any further steps.
Step 2 – Italian or German model?
Often, that cover is broken or missing. What do you do then? Take a closer look at your power take-off shaft: does the shaft have any universal joints on either side, or a wide-angle coupling on a certain side? What model of profile tube is on it? The answers to these questions will give a good indication of whether it is a German or Italian model. Italian models often use triangular tubes and the German variant uses lemon-shaped or star-shaped tubes. With this information, we will know what group of PTO shafts to search in.
Step 3 – Measure various components
Now take some measurements. Measure the universal joint, which is in the coupling; The Universal joint Cap diameter dimension and the length of universal joint end of cap to opposite end of cap. On the universal joint you will often find a number to denote the size of the PTO shaft. Measure the profile tube too. The diameter of the sliding rings on the cover is another useful measuring indicator. The cover is often missing or worn, so it is a good idea to measure inside the groove the rings go in.
Step 4 – Determine size
Once you have all that information, you can often determine the size of the PTO shaft. This does not tell you everything, because you still have to determine what kind of connections your tractor and machine have. Determine the thickness of the PTO stub and how many splines are on it. Another point to note is whether this PTO has a sliding, neutral or other type of coupling and security for that machine. You will need to take that into account too.
Step 5 – Determine length
Next, determine the length of the PTO shaft. All power take-off shafts come in a few basic lengths and it is common for them to need to be shortened. There is a lot of difference in the sizes and lengths of the PTO shafts; this is related to the driving force needed. Measure the length from the centre of the universal joint to the centre of the opposite universal joint in the shortest position.
Step 6 – Setting the Clutch Device
Often the clutch device has a setting marked into the side of the clutch housing. This is something to keep in mind when purchasing a new PTO shaft. You will want to buy protection device with the same torque setting. If you pick the wrong setting, the machine will not function properly and may even suffer serious and expensive damage.
Want to find out more?
Kramp employees have a lot of specialised knowledge about agricultural machinery and identifying the most suitable accompanying parts. Explore our assortment of PTO shafts here. If you would like to find out more or have any questions at all, please contact your account manager.
