Gear diff
 

Was thinking of putting a gear diff in my sons b4, just for easy maintance. What oil to put in it ( weight) runs on grass with a 13.5/17.5 ?

Do you mean B4 or B4.1?

The gear diff will go in the B4.1 no problem but it will not fit the B4 as the diff outdrive bearings are a different size (B4 is imperial and B4.1 is metric)

It's a b4.1:blush:

What oil is a good starting point?

I used a good quantity of black grease and had no issues.

Same here!

It really depends on the surface you run on. The more grip the thicker you can go.

Grease will just give you a very free and an open diff. I run on an all Astro track and use Mugen 1.000cps but will be trying 3.000 when the weather let's me. :yawn:

What are the advantages / disadvantages to running a geared diff as opposed to the ball diff?

- a lot less maintenance
- 0% slippage

I only use grease because I've had trouble keeping thin fluid in the diff but you can buy different weight diff grease. Kyosho sell it.

http://i59.photobucket.com/albums/g2...l/04d8d311.jpg

That won't run out!!