Dumb question #1
 

Coming from a nitro background I am more used to spider/planetary diffs than the ball diffs in the Kyosho so it came as a bit of a surprise when the diffs loosened themselves when twisted!! Is this normal? I have assembled as per instructions and even got some nice new ceramic balls for the build. It seems as though the locking nut in the shorter part of the diff is unscrewing itself from the long bolt running through the centre shaft. Construction has ground to a temporary halt until I know if this is ok!!:rolleyes:

No, the diffs should not loosen themselves if assembled correctly. A good starting point for the diff is fully hand-tightened (no force), and backed off 1/8 turn.

this not ment to happen. Please check it again, Have you got the thrust bearing in? have you got it in the right way? So many things it could be. If you think you have built it correct then please try to discribe in order to us the parts going together.;)

once you have sorted the diff out, make sure you shim it correctly. follow the manual for the number of thin and thick shims, then move one thick shim from the inside of the gear to the outside so it makes the mesh slightly tighter. don't worry if you think it is a bit tight as the gears bed in after a quick run.
this will stop you stripping bevel gears. also get the slipper set correct before you thrash it in anger.

I checked and double checked the diff assembly and all was fine. I tightened the diff and then set the screw back a little to allow the cup to rotate. I have now fitted the diff into the rear housing and checked again and all seems well!!:eh?: I don't know exactly waht was going on before but whatever it was, it aint doing it now.
I have the front diff here and it is loosening/tightening itself when I twist one of the diff cup one way or the other!! All is as it should be but I am mystified!

Sounds like you will have to rebuild the diff as something is not right. A tip for lubrication, a little silicone grease on the main balls and plates, a lot of black grease on the thrust assembly and tension spring.

Not really sure what the problem could be. I can disassemble the diff by holding the gear and twisting the long diff cup!! The only thing I can think is that the thrust bearings are not letting the bolt turn freely in its cup. I will take it apart and have a look. Cheers for the help fellas.;)

Ok well the answer to the dumb question is that the car has a dumb owner!! I had fitted one too many thrust bearings and effectively locked the balls against the inside of the diff cup. I removed one, fitted the correct number (7) and the diff spins lovely. Let the build recommence.:rolleyes:

Oh good.

Nice to hear you have sorted it out.

I hate that feeling when the manual is not lining up with the build, so gutting lol.:D

The manual is not the best! I was warned before the build started that this would be the case. I have worked on GS trucks in the past and their manuals are the worst but Kyosho are hot on their heels I have to say!!
In this particular case though, I can't blame the book. It was all me and my inability to count to seven properly!

LOL. we have all done it, its the excitement, I tend to rush, once built a HPI R40 clutch the wrong way round, hehe

:wtf::D