cannon

iTrader: (35)

Easy test to see what is not working in a ball diff.

Take the ball diff and turn the diff halves in your hands. It feels gritty? OK, then grab each diff half and push hard inwards so that you are pushing the two diff halves together. While doing this rotate the diff halves ... still feel gritty? If it feels heaps smoother than it is your thrust bearing playing up. If it still feels gritty then it is the diff balls .. replace them.

Pushing inwards take the pressure off the thrust bearing so you can determine where the problem is

HTH

k_bojar

iTrader: (30)

where's this article at? i'd be curious to see if before I build my FGX

speaking of building...anything really important that needs to be replaced/updated compared to the car in kit form? figured i might as well get everything together BEFORE i start the build

liljohn1064

iTrader: (17)

The build diff article is located here on the 3 racing web site.

fredswain

iTrader: (1)

Last night I built the gear diff my way like we did for dirt ovals back in the late 80's/early 90's. It is as smooth as butter now. I need to do drive it now to see how it works out. I'll rebuild the ball diff sometime soon. It's sad that it comes that way at all.

BlueEagle

Any suggestions on where to buy a M2.6x0.45 screw tap for building the gear diff?

shano83

iTrader: (8)

Hey blue checkout your local hardware store.

BlueEagle

I tried a few (Home Depot, Lowes, and Harbor Freight), but they don't seem to have anything that small. I bought a Great Planes tap set a while back for my other RCs, but that comes with 5,4,3,2.5,2 mm taps. No 2.6mm tap is in the set. Only taps I've found online that are 0.26mmx0.45 were around $20 + S/H, which seems pretty expensive for a tiny tool that I'm going to use 3 times.

shano83

iTrader: (8)

Sorry blue I can't really help u any further as I'm in another country!
The only solution I say would be bite the bullet and spend the 20 online.
At least u will have for the future and you never know when u will need it.

Actually u could use a normal drill bit and the screw should create its own thread marks. It might be a little bit tighter to use while doing it but try using a little bit of bearing oil to try and ease it

fatboysracing

iTrader: (15)

two words: Mcmaster Carr

RicerX1

iTrader: (45)

I couldnt find a m2.6 x .45 either. I ended up getting a m2.5 x .45 from McMaster and it worked pretty well.

fredswain

iTrader: (1)

I use microfasteners.com for all of my small nut/bolt needs.

fredswain

iTrader: (1)

I rebuilt the ball diff last night. What a horribly designed pos. The diff rings need to be larger in diameter so they can go closer to the edge of the gear. It you run the diff balls on the outers holes, the edge of the diff rings is right at the centerline of the diff balls which is horrible. Since the diff isn't sealed off from the outside any little bit of dust, dirt, and grit can get into there and into the diff. I cleaned mine thoroughly and then carefully sanded the diff rings flat on 600 and then 1000 grit sandpaper, cleaned the diff balls clean, and then installed only 6 of them using only the inside holes. A small dab of black Associated black grease was used in each hole before the balls were installed. It is much smoother now. It will still probably get gritty but right now it's quite nice. I want to find a way to completely seal off the gears into their own box. Not having one in my opinion is a huge design flaw.

MantisWorx

iTrader: (28)

Black grease is not for Ball difs Fred take that stuff out it will slip and melt the spur gear. You want the white "ball dif grease" which is a stickier type of grease.

fredswain

iTrader: (1)

I used to always use it with no issues. Just very sparingly.

EDIT: I remember now that I used it on the thrust balls in my RC10 diff but not on the diff balls themselves. Damn it!

InspGadgt

The more diff balls you use the smoother the diff will be. This is why pan car diff gears are ending up with more and more holes.