I have a question about the 1/8 FLM hybrids. Should there be any "gear whine" or should the gears quite.

I dont have hybrids, but I do have UE cases with the HB gears. When I bench test the Gmaxx I dont hear any noticeable gear whinning, but then again it would be hard to over the noise of the motor and spur/pinion etc. I would say check it by hand, to see how much slop there is between diff pinion & ring gear, should only be a tiny amount of play in any direction.

I don't have mine assembled yet so I am not sure.

Thanks Neil, Yea thats the problem I have, I can't tell if theres any gear whine because of the noise. I have checked by hand and can't find any problem. The reason I think there is gear whine is because when I spin the gear I can hear a whine but I can only hear it when I spin the drive cup because you can't spin the pinion fast enough. Should the case be filled with grease or just enough to cover the gears? I am going to pull it appart again and see if I missed something

When you say case, do you mean the diff cup or the whole thing? My diff cups are filled with 5k and 7k (front & rear, I forget which is which now...), but I just put a light coating of tamiya ceramic grease on the ring & pinion gears. As I turn the wheels by hand, you can hear a low pitched whine as the gears mesh and rotate against each other, but I think that normal for all metal to metal gears really.

Yea, My diff's are filled with 7k and 10k. I was talking about the hybrid case and I use grease on the ring and pinion there too. I was getting that low pitched whine, But I found (after shimming and taking it apart and looking at everything a dozen times) that one of the bearings(new one) on my pinion gear was bad. I replaced it and now I can't hear anything not even the low pitched whine. I went back and checked my other bearings and found two more bearings were bad, But I could not tell they were bad until I put them under a load. I was loading my bearings by putting them on a shaft (correct size, 8MM in this case) and rolling them up and down my leg. Simple but effective. I guess the moral of the story is, Don't trust bearings even new ones.

Glad you found the prob! I was rollling mine of the floor last night and it makes no noise, but I' using UE diffs. If you have something preloaded, it will make noise. Running them loose will not make noise when new, but they will wear and then start to make noise.

Don't use any more grease than what's needed to cover the ring gear. Excess will just make for a mess when you want to change diff oil. I'm starting out at 7K front and 1K rear.