Shaftec advises how to measure a driveshaft
As part of its objective to inject free technical information into the aftermarket, this month, Shaftec advises how to measure a driveshaft.
Furthermore, the expert supplier of remanufactured and new drive, steer and stop parts explains why, for fitment purposes, it is so important to get the measurements right.
This guide follows the introduction of 69 new part numbers last month, and a further two in April (C303L and C303R) This month’s offer covers 13 applications and caters for a range of Citroen and Peugeot models.
The drive shaft is a component of the drive train in a vehicle and is located next to the car’s wheels. Its purpose is to deliver torque from the transmission to the differential, which then transmits torque to the wheels which allow the vehicle to move.
Although the length of driveshafts can vary significantly – which is clearly crucial for fitment purposes – the diameter of the bar isn’t so much of an issue in most cases as the strength comes from the quality and grade of the steel used.
In general, driveshafts are a bespoke component, individually designed to suit the make and marque of vehicle to ensure it can handle the power and torque that the vehicle can produce. There are instances where a part number will have multiple applications, but this is mainly due to motor manufacturers sharing common parts like Volkswagen, Audi, Seat & Skoda V.A.G.
To get a perfect and safe fit, every time, a driveshaft must be measured in its fully compressed state. There are many reasons you can’t simply visually gauge the correct length by comparing it to the old one.
- The ends of the component are packed with grease (picture 1)
- In addition, the component could be sprung. A worn unit will have a lesser spring effect giving it a shorter appearance. (Picture 2)
- You must consider that once the old part has been removed, the properties of the rubber of the boot mean it will try and revert to its original size – making the new unit appear longer than the old one. (Picture 3)
- Once you’ve established all of this, the easiest way to get a correct measurement is to stand the driveshaft on its end, push down hard then…measure. There are other things to consider when it comes to making sure the unit is the correct size for the vehicle it’s to be fitted to. You should check:
- The spline count on the joints. The number of splines will help decide if this is the right application. (Picture 4)
- Ascertain if the part has a centre bearing
- Check if it is a one piece with a single shaft, or a two (Picture 5) shaft piece with a joint in the middle
- And lastly, determine if the part is to be fitted on a vehicle with Anti-Lock Braking (ABS) and if so, check how many ABS teeth it has or if it has magnetic pick up.