Ball diff - Less Balls?
 

I recently picked up a resto project from ebay (F201) and upon dismantling we found that the Ball diffs at the front and rear were both missing balls :o

there are 10 holes in the gear for balls and yet only 5 actually contain balls. The instructions show 10 balls.

Are there any reasons/advantages to running less balls?

It will make the ball diff tighter and rougher (but only by a very small amount). Not something I would ever do intentionally myself but the previous owner may have had a reason. Or they may have just dropped half the balls when building it.

Cheers for that, was trying to figure out the reasoning..... We'll rebuild with the full compliment of balls

As they say in tennis...... "New Balls Please!" :)

Good call. The more balls the less end load needed to create the friction required to transmit the power. It's been tried a lot in 12th, but as only one visit to our better diff-building drivers soon convinces anyone, a diff with a full compliment of round things as designed will give the best transmission of power and diff action. HTH :)

Possible it was a back up car and only had enough balls for a complete diff so half in each would be adequate for one event.