Replacement 10-spline lower shaft used in Winters Performance 10-inch 1500 HP rated quick-change differentials. Item #17 in the exploded view.
This 5003-V shaft is manufactured using Vascomax® 350M (also known as C350 / Maraging Steel 350), an ultra-high-strength specialty steel used in aircraft and military equipment.
With high tensile strength and toughness, it is resistant to thermal effects, maintaining dimensional accuracy and gear engagement precision even in race vehicles subjected to repeated heavy loads. As a key component of a quick-change differential that bears significant force through the engine, transmission, and driveshaft, this shaft is prone to twisting and wear in high-power vehicles and those equipped with high-grip tires; we strongly recommend frequent replacement and keeping a spare on hand.
About Vascomax® 350M
Vascomax 350M is a specialty steel known as "Maraging Steel." Unlike standard steel or chromoly, it possesses extremely high toughness and resists deformation under high temperatures and high loads, despite having a very low carbon content. It is a material used in parts that must withstand severe impacts and torque, such as aircraft components, fighter jet landing gear, and Formula car gear sets.
It is a material that is both hard and crack-resistant, ensuring long service life in high-load applications.
Specifications
Material: Vascomax® 350M (Maraging Steel 350)
Spline: 10-spline
Application: Winters Quick-Change Differential Lower Shaft (Standard equipment for 10-inch 1500 HP rated differentials)
Item #17 in exploded view
Features
Uses aircraft-grade material that withstands high torque and high RPM
Resistant to wear, twisting, and pitch deformation, maintaining gear spline accuracy for the long term
Excellent heat resistance with minimal strength loss during temperature increases, such as during racing
Real-world Benefits
Stable gear engagement → Reduced internal differential noise and vibration
Reduced shaft distortion and twisting → Suppression of uneven gear wear and damage
Resulting in extended lifespan for gears, bearings, and seals
Notes
Please verify shaft compatibility in advance.
Perform proper backlash adjustment during assembly.
Professional installation by a qualified specialist is recommended.
※ Some Winters quick-change lower shafts utilize a 32-spline model. Please check your differential's spline count before ordering.
For information regarding the heat-treated lower shafts standard on 1000+ HP quick-change models, please click here.
Before ordering
〇Regarding import taxes
At Shaft-Ya, we cover the import taxes incurred upon entry into Japan, so there are no additional costs beyond the total amount paid at checkout.
〇Compatibility verification
Our entire product database is based on North American (USDM) vehicles, so please confirm compatibility with Japanese (JDM) vehicles before ordering. (If you are unsure if a listed product fits your vehicle, please feel free to contact us. Our support team will be happy to investigate for you.)
If an order is placed without verifying compatibility, we cannot accept returns due to incompatibility.
Please note that even if a product is sorted by selecting the year, make, and model in the tabs on our homepage, it does not guarantee that the product will fit Japanese-model vehicles without modification.
All product descriptions have been translated into Japanese using software. Please be aware that there may be confusing expressions, and if you have any questions, please contact us before ordering.
○Regarding shipping
Shipping costs are paid at the time of checkout. Shipping estimates are calculated automatically once you enter your shipping address on the checkout page. For large items such as body parts, the actual shipping cost may occasionally differ significantly from the automated calculation. In such cases, we will contact you individually via email.
All products are generally shipped internationally from our U.S. warehouse. Unlike domestic Japanese shipping, international shipping takes approximately 7 to 14 days, so please allow ample time for delivery. If you are in a rush, please contact us for a delivery estimate in advance. All products are shipped via air freight; we do not use sea freight.
○Regarding Japanese vehicle inspection (Shaken) compliance
The products we handle are designed and manufactured outside of Japan. Please note that they are not compliant with the "Japanese vehicle inspection (Shaken) system," and we cannot provide strength evaluation documents or similar certificates for this purpose. Therefore, all parts are sold for the purpose of "use on circuits, private property, or off-road," and installation and use are at your own risk.
○Regarding warranty
Please inspect the contents immediately upon arrival. As all products are shipped internationally, there may be shipping damage to the packaging or the product. We will only provide returns, refunds, or exchanges for products with shipping damage, defects, or incorrect items if you contact us within 7 days of receipt. Please understand that for products sold through our company, all warranty-related support will be handled exclusively through us. We do not provide support through other companies or distributors located within Japan.