By now many of you awaiting the release of the all-new #YZ4SF have seen the many pre-order announcements but no official close-up shots. But as we wait for those close-up photos to become available, let us go over those teaser shots of the new diffs, height-adjustable housings and arms recently posted by project lead Shin Adachi.
During the initial stages of development, some of the key features addressed by the team were 1) an efficient driveline, 2) easy access to the diffs, and 3) adjustable diff height.
Two key goals to achieve an efficient driveline were reduced rotational mass, and minimal center shaft angles. The new gear diffs feature a thin bevel ring gear with a center cut-out design to reduce weight, and the input gear designed for minimal mass as well. However both are made from steel so that strength and durability are not compromised. The center shaft angles throughout the driveline have also been reduced to a minimum, to eliminate as much driveline bind as possible. This helps to provide excellent power delivery, acceleration, and throttle response. Certainly a huge plus in the stock motor categories that have seen a big increase in popularity.
As you can see from the photos the diffs are enclosed in transmission housings to keep out dust and debris. The transmission housings mount into machined aluminum bulkheads, with easy removal to service the diffs.
Although adjusting diff height is a common tuning feature on today's on-road touring cars, no other shaft-driven 1/10th 4wd buggy has had this feature until now. With the increasing number of carpet and turf tracks worldwide, diff height adjustment will undoubtedly become an important part of dialing in your setup from low to high grip. The height adjusting cams are attached to the bearing holders on the housing to allow the entire housing to be raised or lowered, effectively raising or lowering the diff as well.
New lower suspension arms were also developed, with an improved plastic formula used for both increased stiffness and durability.
This covers just a few of the great new features on the #YZ4SF, with more details to be uncovered soon!
-from Team YOKOMO Facebook