How tight does a diff need to be? 1st ever kit.

[Evo_ermine]

Hi, I'm just building my first kit, an Ansmann SC4, and am stuck on the diff. It says once the diff is assembled to 'use a screw driver in each end to secure the hubs either side and rotate the diff case until it becomes tight'.

How tight is tight? I'm bit baffled as it's got tiny ball bearings inside, so presumably the point of that is to allow it rotate inside. But if i do it up tight it'll not allow them to rotate on the bearings. I've tried and it needs a lot of pressure to rotate the two halves when done up tight.

I know nothing about diffs so any help is appreciated.

Edited October 5, 2012 by Evo_ermine

[UltimateRC]

Tight enough so the diff isn't sloppy but not too tight that it doesn't rotate smoothly.

[lorrylemming]

http://www.petitrc.com/setup/How2ProperlyBuildandBreak-InaBallDifferentialandSlipperClutch.html If its a ball diff (think it is) then have a look at this link.

The general idea is that if you hold both out drives still, with two screwdrivers or something, then the centre gear shouldn't be able to rotate. It might rock a bit but not be able to rotate around.

[Evo_ermine]

http://www.petitrc.c...pperClutch.html If its a ball diff (think it is) then have a look at this link.

The general idea is that if you hold both out drives still, with two screwdrivers or something, then the centre gear shouldn't be able to rotate. It might rock a bit but not be able to rotate around.

Thanks guys. Those vids were very helpful. The instructions in the manual are pretty dire so it's nice to see how much grease to use and stuff like that. I've had to build 2 diffs, once for front and one for back, and then there's another 'thing' i've had too build two of, a sort of arm with a cog on it which meets the big diff cog, but the manual doesn't explain what it is. Currently bit baffled how to put the smallest 'E-Ring' in the world onto that.

I've messed up already though when installing some parts to the chassis...the hex screws are so soft and a couple have rounded off without being all the way in. Now I can't get them out or in! I need a dremel or something to cut a slot in the screw so I can use a screwdriver to screw it home.

I'm not sure I'm meant for kits...!

[UltimateRC]

Most Ansmann kit screws are carp anyway... The trick is not to get frustrated... Either dremel a slot to screw it out or drill out... There's always a way:)

Have you done the servo saver yet? I find them tricky...