Shimming the Gears at the Kyosho ZX5 FS

[Highjumper]

Hello, i have Problems with the Main Drive. Me rear Plastik Pinions do not hold long. Which Shimming do you use! The orginal ,oder do you shimm nearer??

I hate this Plastik Parts! :-(

Greets Kim

[SimonW]

Put all shims on the short side to shim tighter, i use 3 silver and 1 brass.

HTH SimonW

[RogerM]

You have to shim each set up individually like you do with any shaft driven 4wd.

Put the diff in with 2 silver on side with the crown wheel and 1 silver and a brass on the other side.

Place your thumb against the toothed side of the crown wheel and gently push the crown wheel away from the pinion.

Rock the pinion and check the free play (backlash). If there is none swap one of the 2 silvers for the brass and try again, if there is loads then move the brass to the same side as the 2 silvers. Keep moving the shims around until you end up at the point you can "feel" a little backlash but can not really see any.

I have shimmed my 4wd cars like this since the down of time and have NEVER had a Kyosho gearbox failure. Using this method allowed me to run a full season with just one set of gears in a Pred P8!!!

Give that a try!

[Highjumper]

Ok, what do you mean with "backlash", sorry!!


And have you made something with the small Pinion?! Shimming ,too??

Kim

[Fabs]

I do pretty much the same as Roger and haven't had a single issue. The layshaft pinion just need a minimal play but out of the box it's pretty good already.

[chb]

I read Roger M ... like this:

Backlash = play

# If too much play, recipe for disaster as the gear's teeth "attack" each other at wrong angle... skimmed gear
# If no play at all, desaster also because force=stress will lead to overheating and finally destroy the teeth

So shimming is fine art... As Roger puts it "feel the play with the sensitivity of your fingers, but so little that you can't see it"

[Highjumper]

Maybe this was the problem too.!!

Look at this Part.

i have Shimmed now the Small gear, und the big Gear . I hope now it will be good.

Greets Kim

[Fabs]

of course this is your problem.

I hope you've replaced that layshaft now!

[Highjumper]

Yes, no wi have replaced teh Shaft, and so i will hope it will run.

How open do you have your Slipper! Do you hear it ! The problem is when i drive on Astroturf. Then i will make the Slpiier realy Stiff.

On Dirt i run it not so stiff

Kim

[Fabs]

On astro i run It tight but not too much. You shouldn't be wheelying.

[RogerM]

I set my slipper so it gives for about 30cm in a 4wd just to manage the weight transfer. Can run tighter than most with the FS as the forward motor position means there is less fore/aft weight transfer on acceleration breaking compared to most.

[Highjumper]

Ok, i will check this! We have at the Weekend a Race in Astroturf, so i will see.

Thank You.

Kim