Today let's do something quick with this stock Mini-Z MA-020 gear differential. This is the unassuming diff found in all Mini-Z AWD, FWD and buggies. It works quite well actually. It's a completely "open" differential. Let's add some grease to slow down the diff action.
To get to the spider gears inside, partially disassemble the diff. It's not necessary to pull out the diff cup on the right side. Simply unscrew the three screws holding the cover on. It's a standard gear differential design. The grease will go on the three spider gears.
I'm going to use the thickest grease I have, the Atomic 35K. It's all pretty simple. Do not use oil because it will leak from this unsealed diff case. Use a thicker grease to best avoid any mess. With the diff back together, the effect of the grease on the diff action is pretty obvious. There's definitely more resistance. It's slower but still smooth.
So why make this change at all? First of all, this tuning method isn't that important to my MA-020 because I mostly mess around with it at home. Rather, what's most useful from this exercise is verifying that it's possible to tune a stock gear diff with grease. It's potentially relevant for my MB-010 buggy and Carisma GT24TR.
Choosing how to tune diff action is complex, depending on traction level and cornering demands. Plus, the effects of tuning the front differs from the rear diff. Roughly, at the front, a looser diff has better turn-in cornering speed but less exit speed. A tighter diff has the opposite effects. Another way I understand this is that a looser diff rotates the car better (more aggressive steering), but a tighter diff accelerates forward harder (more stability). I need an AWD track car to really learn about this properly. In the mean time, in the description below I'm including a link to some literature I found useful.
(I'm eagerly waiting for the Atomic BZ4 to come out!)
By the way, a ball differential can be adjusted for diff tightness by changing its tension. At the moment I don't have a quality AWD ball diff.
This MA-020 is power sliding quite competently. That said, it did well with an open front diff too. Next time I really need to move that chair on the right. It's giving me a lot of anxiety. This is Sammy and thanks for watching!
Useful read: www.rctech.net...
Music: "Instructions for Living a Life", Savfk ( • Instructions for Livin... )