Drivetrain› Manual Transmissions and Components

Synchrotech

Transmission Rebuild Kit

$404.20

SKU: SYN-BSK-SYN101B

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Overview

The Synchrotech BSK-SYN101B is a brass rebuild kit for manual transmissions. It is designed for Y80, S80, S4C, S21, and Y21 transmissions, specifically those with B16A, B16B, or B18C engines.

The kit includes 1-5 brass synchros, synchro springs, a brass reverse synchro and spring, five shaft bearings, two axle seals, an input seal, a shift rod seal, and a new dust boot.
Show original supplier description
The Synchrotech BSK-SYN101B Brass Rebuild Kit is engineered to restore and enhance the performance of specific manual transmissions. This comprehensive kit is designed for fitment with Y80, S80, S4C, S21, and Y21 transmission codes, commonly found in vehicles equipped with B16A, B16B, and B18C engines. This rebuild kit provides all the necessary components for a thorough transmission overhaul. It includes five brass synchros, corresponding synchro springs for gears 1 through 5, a brass reverse synchro with its spring for reliable reverse gear engagement, five essential shaft bearings, two crucial axle seals, an input shaft seal, a shift rod seal, and a new dust boot to ensure proper sealing and operation. The use of brass synchros in this kit offers improved shifting feel and durability compared to standard materials. This upgrade is particularly beneficial for performance applications where precise and quick gear changes are critical.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandSynchrotech
Part NumberSYN-BSK-SYN101B
CategoryDrivetrain
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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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