3D Model Library
Synchro Hub Assembly Tool
Spring & Ball Insertion Helper
by Cole GentrySecure checkout via Stripe. Files unlock instantly.
These files are provided as-is and are not certified for road use. You are responsible for verifying any part's strength, fit, and suitability before fitting it to a vehicle. Classic Mini DIY and the model's author accept no liability for printed parts.
License
The buyer may download the purchased files, produce unlimited physical prints for personal, non-commercial use, and provide the files to a third-party print service solely to produce prints for the buyer's own personal use, provided the service does not retain, reuse, or share the files beyond the print job. A purchase grants access to every version of the model, including versions published later, while the model remains available in the library; each version is governed by the license in effect when that version was published. The buyer may not otherwise redistribute, resell, sublicense, share, publish, or upload the files in any form; may not sell, trade, or commercially distribute physical prints made from them; may not create and distribute derivative or remixed versions; and may not remove or alter any attribution, credit, or notices included with the model. Files are delivered immediately on purchase, so all sales are final and non-refundable except where a refund is required by law. All rights remain with the creator. Full terms: https://classicminidiy.com/legal/paid-file-license
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About this model
If you've ever rebuilt a synchromesh hub, you already know the moment of dread: you've got the hub splined onto the inner retainer, three little detent springs and three even littler balls staged and ready, and the outer sleeve hovering above it all. You compress the first ball, start sliding the sleeve on, and ping — one of them launches itself into the far corner of the workshop, never to be seen again. Then you do it twice more. This simple printed tool takes that fight out of the job. It holds the detent balls compressed and flush with the hub while you slide the synchro sleeve into place, so everything stays where it belongs and seats cleanly the first time. No third hand, no magnetic pickup tools, no crawling around the floor with a torch hunting for a 3mm ball bearing. Just stage the springs and balls, fit the tool, slide the sleeve home, and remove the tool once the sleeve has captured everything. It's the kind of thing that turns a genuinely frustrating ten-minute wrestling match into a thirty-second operation, and it makes the whole synchro assembly far more repeatable — handy if you're rebuilding more than one gearbox or just want the satisfaction of getting it right on the first try. Print notes: No supports needed 0.2mm layer height is plenty; the tool isn't a precision part, it just needs to be dimensionally consistent 3–4 perimeters / ~20% infill is more than strong enough for the light loads involved PLA or PETG both work fine — PETG if you want a little more give and durability around solvents and gear oil A small print that earns its keep the first time you use it. If you're working through a full A-series gearbox rebuild, this is one of those quiet little tools that saves your sanity.
Print settings
- Layer height
- 0.2 mm
- Infill
- 18%
- Nozzle
- 0.4 mm
Assembly
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