Yokomo S4-503R17A 40T Ring Gear for YZ-4S Competition Upgrade  [S4-503R17A]

Yokomo S4-503R17A 40T Ring Gear[Use w/17T D Gear] for YZ-4S Gear diff
Price:
£20.85
Brand:
Yokomo
Model:
S4-503R17A
GTIN:
0639342210398
Condition:
Brand New
Write a review

Enhance your YZ-4S differential with the Yokomo 40T ring gear

The Yokomo S4-503R17A 40T ring gear is a precision component for the YZ-4S gear differential. Designed to work with a 17T drive gear, it promotes smooth power transfer and consistent gear engagement. The part is manufactured for dependable service in competitive and hobby use.

Compatibility and performance notes

This 40T ring gear fits YZ-4S models such as B-YZ4SF, B-YZ4SF2-1, MOR-010, and MOR-020. The exact tooth count helps ensure proper meshing with the 17T drive gear, supporting predictable throttle response and reduced gear wear.
Remark :
Due to limited stock availability, please notice that some Yokomo items may have to order from the factory and the ready time is around 4-6 weeks. Customer purchases the item is assumed to accept the waiting time which allows us to order directly from the manufacturer if the item is out of our warehouse.

How do I confirm this part fits my differential?

Compare the part number and tooth count to your current ring gear and check the mounting pattern. If they match the listed YZ-4S variants, it should fit directly.

Will changing to this ring gear affect handling?

The gear itself does not change ratios, but improved mesh and lower backlash can yield more predictable throttle and cornering behavior.

What routine checks should I perform?

Inspect tooth faces for wear, ensure bearings are seated, and check that the gear mesh remains correct after several runs. Replace if significant wear appears.

Can I pair this with aftermarket differentials?

It is designed for YZ-4S standard gear differentials. Aftermarket units that keep the same mounting and tooth spacing should be compatible, but verify dimensions first.

How should I break in a new ring gear?

Run light sessions and check for unusual noise or heat. Recheck mesh after the first few runs and tighten or adjust as needed to maintain smooth engagement.

Copyright © 2008-2025 rcjaz.co.uk All rights reserved