How often to change ceramic diff balls?

[Timee80]

I rebuild my diff fairly regularly to keep it in good working order. I always use ceramic balls and normally change them after ive rebuild 4 times or so. How long should the balls last? Am I changing them too often and just wasting money?

[Rich D]

Hi Tim

I changed mine before the nationals and havent rebuilt the diffs all season. I only change the balls if the diffs still feel gritty after a rebuild. Its usually one of the balls thats chipped but its impossible to see which one it is.

Ive just rebuilt the diffs ready for indoors as a matter of course. I think people either rebuild them too often or run them too loose so they slip and wear the plates out too quickly.

i dont expect to rebuild my diffs again until before next outdoor season

I use the ceramics from RCLazy.

HTH

[sparrow.2]

Technically, if your diff hasn't slipped and/or run without grease the balls should be good for at least a season.
Every 4 rebuilds seems a bit much unless you're only doing rebuilds once a year

[Timee80]

I think im changing too often then. I rebuild whenever it doesnt feel perfectly buttery smooth. I never let it get anywhere near a bad notchy feel. I always thought that looking after the diff was the most important thing to do in 2wd. Ill ease off the maintanance from now on

[MikePimlott]

If a new ceramic diff feels gritty and horrible its usually crap in the thrust race.
A quick strip down and clean and re-grease your away again. Ceramic balls should wear the diff plates before the balls themselves wear.
I only change ceramic diff balls when i change cars

[mattybucks]

Everytime you rebuild the diff, and only replace with Buds Balls supplied by Telstar Racing..................... I wish.

I agree with the above posts, when/if it starts feeling gritty after a rebuild.

Also use some really fine wet and dry on the plates with a bit of clutch cleaner on the paper to get your plates super smooth.

[Timee80]

I thought super smooth plates encourages the diff to slip? You need some grip for the balls to work the plates

[Rich D]

Originally Posted by Timee80

I thought super smooth plates encourages the diff to slip? You need some grip for the balls to work the plates

The fine wet/dry creates a kind of "cross hatchings" appearance on the plates much like when a cylinder is rebored. Its doesnt make them mirror smooth. I did mine last night. Its more the fact that it makes the plates flat rather than smooth. Use about 1000 grit with brake cleaner for lube as someone above said.

Best diff rebuild video i have seen is here.

http://www.youtube.com/watch?v=YOMu6Fu3orI

I use this exact method, just using a very small smear of the hard grease on the backs of the plates or else it will contaminate the diff lube. As i said, i only rebuild once before outdoor season and once before the indoor season. I use a bit of foam in the outdrive to stop dirt from getting into the thrust race ( foam compensator out of the top of a shock ), and then use diff protectors on the Tamiya too.

A dirty thrust can make it feel gritty, but in my experience, as i always clean and regrease the thrust when rebuilding anyway, its a chipped ball thats causing it. I have Matt White to thank for pointing that out to me some time ago.

HTH