Pro Series 300M Stub Shaft
40 Spline

Sometimes it’s best to take a step back, look at an already proven design with an open minded attitude, and start from scratch. This may sound strange, why change something if it’s already working? It’s the heart of engineering, with Ultra4 growing as fast as it is staying on top of the curve is the best insurance you can have for securing that next podium finish.

Say hello to the all new 40 spline Pro Series Stub Shaft, a reinvention of our already proven Ultimate Stub Shaft. Manufactured out of billet 300M aerospace material, with an integrated positive locking design, all while achieving 50° of steering, it’s the next best thing in stub shaft technology… and the last stub shaft you will ever need.

Pro Series Stub Shafts are designed to work with 60 style u-joints and Spidertrax 40 Spline Ultimate Unit Bearings.

$1,099.00
MSRP:
$1,099.00
Availability:
Only 0 in stock.
Availability:
Made to Order
Ship Date:
Model No:
AXLLSKU40M
 

Overview

Aerospace Quality

We don’t use the term “Aerospace” lightly. Yes, the Pro Series Stub Shaft is manufactured out of the finest domestic military grade 300M on the planet, but there’s much more that makes it Aerospace worthy. We follow the strictest AMS Aerospace standards for our heat treatment, complete with double tempering, snap tempering, and cryogenic treatment procedures. Parts are sampled to ensure proper grain structure is achieved up to 0.0003” from the surface, that’s a depth 1/10 the thickness of a human hair! In summary, you’re getting the best material and the best heat treatment on the market.
Aerospace Quality

Locked

Turning 40° is impressive, but our axle shafts can turn 50°. It’s insane really, Ultra4 racers would often appear broken by the sharp steering radius, and it truly makes the difference when in tight conditions. However, when turned that tight, keeping the shaft happily in the centerline of the knuckle becomes difficult. On our Pro Series Stub Shaft, we’ve solved this problem by positively locking the shaft to the Ultimate Unit Bearing with a billet aluminum cap and cap screw. Keeping that stub shaft tightly secured not only helps with driveline vibration, but helps with overall strength of shaft and u-joint.
Locked

40 Splined

A bit obvious, but the Pro Series Stub Shaft is 40 splined. It’s a size that makes perfect sense, especially when running properly paired inner axle shafts. When sized with the same shaft diameter as inner shafts, stub shafts end up taking the full punishment in your front end. The stub shaft should be “stronger” than an inner axle because unlike an inner axle, stub shafts have little room to twist, making them more prone to failure. An added bonus: with many drivers running 40 splined rear Ultimate Unit Bearings, having the same unit bearing up front makes for better serviceability and part simplicity.
40 Splined

Manufacturing Perfection

We pride ourselves on holding the tightest manufacturing tolerances in the business. We take our in-house manufacturing & engineering very seriously, and never cut corners for the sake of saving a few dollars. The Pro Series Stub Shaft is no exception to this rule. Shafts are manufactured, heat treated, and then returned to the manufacturing table to ensure those high tolerance dimensions are perfect. After heat treatment, we bore the holes for the u-joint caps in one single operation, and in that same setup fly cut the insides of both ears to ensure proper u-joint spacing.
Manufacturing Perfection