Motive Gear RK3500 NV3500 5-Speed Synchronizer Ring Kit

This is the complete set of synchronizer blocker rings for the New Venture NV3500 five-speed manual transmission. The synchro rings are the brass-faced cones that match shaft and gear speed as the slider engages, and they are the first thing to wear out in a high-mileage manual box. When they are worn you get the classic symptoms: a grind going into second or third, a notchy shift that fights you when the fluid is cold, and gears that pop back out or refuse to engage without double-clutching.

The NV3500 (also built as the Getrag 290) was used behind the 4.3L V6 and small-block V8 in 1988-up GM half-ton trucks and vans, including the Chevy S-10, C/K 1500, Silverado, GMC Sonoma and Sierra, and the Astro and Safari vans. Replacing the rings during a rebuild restores clean, quiet shifts without having to source individual pieces one at a time.

On the bench these go in during teardown as the gear stacks come off the mainshaft and countershaft. Replace them as a set along with the keys and springs while the case is split, check your synchro-to-gear clearance with a feeler gauge before final assembly, and set the endplay to spec. Verify your exact NV3500 variant and gear count before ordering. New Motive Gear parts with a 1-year warranty; ships from the USA, handling in 1-2 business days.