Center diff feel in the hands

[BruceRC]

I recently picked up an Arrma aluminum pre-assembled center diff (the one with 200k). I took it apart to check the fluid and it was very low. The thing that I wondered about was that if I held a cup in either hand and spun the diff, I could feel the gears inside meshing ever so slightly. It's hard to explain but it's like feeling the teeth of the gears meshing. I decided to return the center diff because it wasn't filled properly and I honestly thought this issue of being able to feel the gears meshing together (almost like little tiny bumps as I spin it) could be an assembly problem.

So I got a replacement, and this one has the same feel when spinning it in my hands. Although this one is filled properly. Is this feeling I get when holding it and spinning not normal? I know it's tough to explain it, so apologies there.

 

[Garcbomber]

Spin it in a powered drill ~1000rpm for a few minutes, probably just new cast gear mesh. Vice or set of grips on one cup and let it go through a few heat cycles and see if it smooths out(switch to other cup). My vitavon or machined & hardened steel spider/planetary gears are like that for eternity.

As long as it's consistent 360 degrees I wouldn't be too concerned, is it your first alloy cup? Doesn't hurt to pull a shim or two out of the planetary set and feel results. Better to be a "little" tight than a little loose since it's going to endure 150F temps during heavy bashing and fluid will thin allowing more internal radial/axial play...

 

[BruceRC]

Spin it in a powered drill ~1000rpm for a few minutes, probably just new cast gear mesh. Vice or set of grips on one cup and let it go through a few heat cycles and see if it smooths out(switch to other cup). My vitavon or machined & hardened steel spider/planetary gears are like that for eternity.

Thanks bro, I had wondered if it just needed to break in. Then I was thinking, "does this translate to vibration and heat?" Still noobin' it, thanks again.

 

[Senton_Prime]

There is a "break-in" period, imo..

 

[aaronass]

Also need to b properly shimmed. I have had 2 come from amain and had to reshim. Just a thought

Mayb take a shim out