Spidertrax are proud to release the Pro Series 40 Spline Gun Drilled 300M Inner Axle Shafts. With its 7/8″ (22.2mm) thru hole, end to end, this axle shaft boasts the best-in-class strength to weight ratio, critical for keeping your rig both light and strong. Spidertrax 40 Pro Series Axle Shafts have a considerably larger diameter compared to their smaller 35 spline brethren. They are the preferred choice of teams using high horse-power race cars. These Axle Shafts are made using a two-piece design manufactured from 300M and are heat-treated after machining. Please note that Spidertrax 40 Spline Pro Series Axle Shafts are designed and intended to be used with Spidertrax Ultimate and Pro Series Knuckles and 40 Spline Ultimate Unit Bearings. This listing is for all front 40 Spline Inner Steering Shafts from 38″-44″ (965.2mm-1117.6mm). To calculate your shaft lengths please use the “Spider 9 Housing & Shaft Calculator”. This Excel spreadsheet can be downloaded by clicking here. When ordering your Spidertrax 40 Spline Pro Series Axle Shafts, please refer to the drawing below when entering in your measurements for options Sa or Sb. The unit of measurement is inch and this number should be keyed in using decimal format. Please check and re-check all measurements as once shafts have been manufactured it is impossible to change. It is also worth noting that most lockers and spool splines do not work from a central point and it is paramount that you take this into account when calculating shaft lengths. Axle shafts are sold individually (single). Lead-times vary, for an accurate ship date prior to ordering please call or email. Because axle shafts are custom made in the USA, payment is taken in full at time of order and orders are non-refundable. Spidertrax 40 Spline Pro Series Axle Shafts are designed to be sealed using the Spidertrax High Performance Oil Seal Kit and intended to be installed into a Spidertrax Ultimate or Pro Series axle housings fitted with Spidertrax Ultimate or Pro Series Knuckles. Seals and seal kits can be found here. These shafts are designed to be used with Dana 60 style universal joints, Gigglepin offer CTM and Branik universal joints and spare parts, these can be found here.