Kraton Clutch/Spur bearing Spacer & shims?

[Max Attitude]

Hey guys, I tore down my K4s a while ago.
Reason for the tear down was to replace motor bearings primarily. It seemed to have gotten a bit noisy although still ran good. Good thing I did because the bearing in the motor by the pinion gear was toast...

Anyways, I can’t remember exactly where these 3 spacers came from. I think they went between the bearing and the clutch because otherwise my spur rubs the case. I looked up the exploded view on Arrma’s site and didn’t see any shims or spacers. I also didn’t see any in a youtuber’s vid during his tear down.
If I install these it seems to all fit perfectly but the shim or spacer directly contacts the rubber seal of the bearing and not the race. Seems like a bad idea.

And if I don’t install there’s a lot of slop and my spur rubs the case.

Anyone know the solution?

 

[jondilly1974]

Hey guys, I tore down my K4s a while ago.
Reason for the tear down was to replace motor bearings primarily. It seemed to have gotten a bit noisy although still ran good. Good thing I did because the bearing in the motor by the pinion gear was toast...

View attachment 88654

Anyways, I can’t remember exactly where these 3 spacers came from. I think they went between the bearing and the clutch because otherwise my spur rubs the case. I looked up the exploded view on Arrma’s site and didn’t see any shims or spacers. I also didn’t see any in a youtuber’s vid during his tear down.
If I install these it seems to all fit perfectly but the shim or spacer directly contacts the rubber seal of the bearing and not the race. Seems like a bad idea.

And if I don’t install there’s a lot of slop and my spur rubs the case.

Anyone know the solution?

View attachment 88655

Maybe those are parts of the bearing that fell apart.

 

[Camaroboy383]

Hey guys, I tore down my K4s a while ago.
Reason for the tear down was to replace motor bearings primarily. It seemed to have gotten a bit noisy although still ran good. Good thing I did because the bearing in the motor by the pinion gear was toast...

View attachment 88654

Anyways, I can’t remember exactly where these 3 spacers came from. I think they went between the bearing and the clutch because otherwise my spur rubs the case. I looked up the exploded view on Arrma’s site and didn’t see any shims or spacers. I also didn’t see any in a youtuber’s vid during his tear down.
If I install these it seems to all fit perfectly but the shim or spacer directly contacts the rubber seal of the bearing and not the race. Seems like a bad idea.

And if I don’t install there’s a lot of slop and my spur rubs the case.

Anyone know the solution?

View attachment 88655

Those are bearing shields and the ball retainer... not part of the motor.. ?

 

[Freelander]

Can someone link the thing about spacers for this? I saw a video on here somewhere.

 

[Yas]

Those are bits of the bearing after it's died from dirt but you should shim the spur if it's rubbing on the plastic housing or it'll churn out plastic dust that'll kill another bearing

I found these mods helped me to keep the bearing clean

https://www.arrmaforum.com/threads/blx-motor.20999/post-290243

 

[Camaroboy383]

Those are bits of the bearing after it's died from dirt ⚰ but you should shim the spur if it's rubbing on the plastic housing or it'll churn out plastic dust that'll kill another bearing

I found these mods helped me to keep the bearing clean

https://www.arrmaforum.com/threads/blx-motor.20999/post-290243

The spur doesn't rub the housing, the dirt that gets between the clutch hub and the housing is what does.. keep debris out, problem solved.. sure shimming it is a band aid, but it doesn't prevent the original cause (debris entry).. ?

 

[Yas]

The spur doesn't rub the housing, the dirt that gets between the clutch hub and the housing is what does.. keep debris out, problem solved.. sure shimming it is a band aid, but it doesn't prevent the original cause (debris entry).. ?

I'm completely confident it was the spur rubbing the housing and not the dirt getting span around for me. There was so much back and forth play at my spur I felt it rubbing by hand before I shimmed it. I've checked it a few times since where dirt still gets in (I've not taped/sealed the power module) but there's no more scoring on the housing

 

[Camaroboy383]

I'm completely confident it was the spur rubbing the housing and not the dirt getting span around for me. There was so much back and forth play at my spur I felt it rubbing by hand before I shimmed it. I've checked it a few times since where dirt still gets in (I've not taped/sealed the power module) but there's no more scoring on the housing

Correct, you allowed more space for debris to pass through by shimming.. but again it does not cure the number 1 reason for the rubbing or the failure of motor bearings..

If your hub assembly was touching the housing from brand new you had a bad housing or bearing.. the "float" of the slipper assembly is not a bad thing.. it's also not a bad thing to shim it out..

the thing is, it's on a spring loaded center shaft with constant pressure pushing it back towards the rear diff input.. because of this the only shim needed would be against the rearward bearing.. ?

 

[Freelander]

That makes total sense to me! I notice this 'slop' when the power module is out of the car but now that you mention it: it isn't there when fully installed because there is spring loaded pressure from the driveshaft against the slipper clutch.

I haven't noticed rubbing myself when the gearbox is open, but there is definitely dirt in there and there was bits of shrapnel from previous failures of spur gears, but no wearing. There was definitely wear on the chassis from the 91T 48P stock gear the Mega came with, it's a few mm larger diameter than the 32P spur gear from the BLX
I apologise because this literally has nothing to do with OP's exploded motor bearing.

 

[Max Attitude]

Well... lol. I don't know where those parts came from cuz I didn't think they were from the motor bearing.

That makes sense that the center shaft keeps it pushed back as far as the slop goes but what keeps the bearing in the plastic housing? Seems it could slip backwards? I have 1/8th to 1/4" of play or slop.

Maybe those are parts of the bearing that fell apart.

I guess it looks that way lol. I thought they were set aside before I took the motor apart. It was late though so maybe lol