Ok, finally getting to the Bmax4 build here. I’m looking forward to running this car having been a long time Yok fan. One of my favorite 4wd buggies of all time was the Yokomo Mr4Bxf kit. Let’s get started.
The latest Yokomo Bmax III Factory kits are shipping with some of the latest hop ups. The most notable in my opinion is the inclusion of the Lightweight Short Chassis kit, a $95 value! On top of that there are updated shock shafts, shock pistons, steering bellcrank brace, nice aluminum rear hubs and updated springs. I also once again chose a full set of Protek RC titanium screws for my build.
The chassis went together without issue, just be sure to follow the supplemental instructions. Building the diffs was up next and they come somewhat pre-assembled. Now don’t cut corners here, take them apart. You’ll need to remove the anti-rust oil from the outdrives with some motor spray. Remove the 0-rings and lube the diff housing, o-rings, and outdrives with some high speed/temp grease. Don’t go overboard, but don’t skimp here either. The rest of the diff build is straightforward with none of my parts requiring any hand fitting. The instructions have you assemble the diff housings and drop them onto the chassis. Here’s where most guys make a mistake. The instructions show a few shims one one side. This is a “guideline” and may not be the ideal fit for your diffs and housings. In my case I needed a smaller shim to get the side to side diff fitment correct along with the proper “lash” on the ring and pinion fit. The kit doesn’t include them so make sure you pick up some extra shims. You won’t free spinning diffs but you do not want a lot of “lash” or free play on the ring and pinion fit. You also don’t want there to be any rough or harshness on this fitment. Take your time, and get it right the first time. Doing so will give you long life and quiet drivetrain. I lube my ring an pinion gears with some Lucas Oil “RED ‘N’ TACKY GREASE.” It sticks to the gears, doesn’t slow the action down, and is easy to find at your local auto parts store or speed shop. I pack the ring gear, work the drivetrain by hand, and remove the excess.
Building the front and rear hubs was next up and they go together without issue. The included aluminum rear hubs are very easy on the eyes. Bearing fitment is excellent, snug but not too tight. Again Avid bearings are the product I choose. Don’t forget the rear axle spacer between the two bearings. The CVD’s come pre-assembled, but again take 5 minutes and take them apart. They don’t appear to be lubed with anything other than an anti-rust agent. I don’t use a lot of grease on my cvd’s and prefer to use a lightweight oil such as Tri-flo or similar product.
That’s all for now. Stay tuned for Part 2 coming up next week!