optima mid - silicon oil in diff?

[gkatz 58]

hi all
I have noticed something I was wondering about.

in the optima mid rere there is an instruction that I assume is not mandatory that states to use silicon oil inside the differential.

I am not sure if this is instead of grease or together with grease.

it has 2 references in the manual (see pics below),

can someone comment about this? why is it even there? i have seen 2 builds online, one that uses just grease and one that uses grease and in the voice over states that he used solicon oil.

i was wondering if anyone can comment on this.

thanks

[toyolien 5602]

I just used 7000 in the front and 5000 in the rear. The oil will lubricate as well so no need for both. Grease OR Oil.

 

[Wooders28 4873]

On 5/20/2024 at 6:29 AM, gkatz said:

 the optima mid rere there is an instruction that I assume is not mandatory that states to use silicon oil inside the differential.

The kyosho Rere aren't the same as Tamiyas. The kyosho rere, are a newly designed car, that just looks old.

The modern way for gear diffs, is to use silicone oil, as theres loads of different thickness / viscosity and this makes for better tuning.

If you use a thin oil, the diff is really easy/loose, which is great for high grip surfaces, as the car will turn well, and still get the power down.

As you move to less grippy tracks, an inside wheel will start to loose grip, and just wheelspin. So if you then swap out the diff oil, for thicker ,it helps keep power going to the outside wheel (you can get silicone that thick, it essentially locks it, but kyosho are saying 30000cst is the max, presumably ,if you need thicker, youre needing a ball diff) 

There comes a point, where the grip gets low enough, a ball diff is better (faster lap time) though.