Limitless A lil head scratcher

[RuffRiki]

As I’m getting these cars ready for the warmer weather I’m having an issue where the solution isn’t clear.

I have 2 brand new builds with this same issue where there is a wobble at the input shaft drive cup area (See photo) and I’m worried about what this’ll do at high speed. All the components are new and therefore ‘should be’ without defect.

I am trying to get to the bottom of it without changing part after part and still not getting it right. I was hoping it was a bad drive cup but I changed it and it’s the same. So then I’m guessing maybe bad input shafts, maybe the bearings, maybe the diff housing itself, I don’t know. I already illuminated the center drive shaft as the cause since I can see the honky dory at the drive cup when it turns.

I’m hoping this is a simple issue for someone reading this or some good suggestions would be appreciated just the same.

Thanks….

 

[JDFx]

I have the same thing on my new Fireteams rear input shaft cup. I took it apart and checked everything, even swapped out the bearing and it still wobbles. I think the cups are just mass produced and poorly made. I'm hoping to find an aftermarket replacement of higher quality eventually.

 

[Warby]

I have the same thing on my new Fireteams rear input shaft cup. I took it apart and checked everything, even swapped out the bearing and it still wobbles. I think the cups are just mass produced and poorly made. I'm hoping to find an aftermarket replacement of higher quality eventually.

I was just on Scorched Parts RC website and saw these. May be a solution.

 

[RuffRiki]

I was just on Scorched Parts RC website and saw these. May be a solution.

Sigh I was hoping it wasn’t allll that…I have these in another car and that one is st8 and smooth but I was still trying not to think about it like that….

I have the faulty ones broken down in front of me, again. Now I’m noticing a hair too much annular space in the cup hole over the shaft, so when I tighten the grub screw it seems to pull the cup to one side on the shaft…

 

[Warby]

yep that would do it. puts it off center.

 

[Jchammbone]

No experience with that model ..but is it possible to shim it opposite of grub to help keep it on center? Vey thin piece of brass stock from craft store maybe..
Only trying to help. Good luck!