Bearings mayhem

JvG

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Arrma RC's
  1. BigRock 4x4
  2. Kraton 6s
  3. Kraton EXB
  4. Typhon 6s
Hi all,
i need some help. I have a Kraton V2 and a Typhon V2 on 6S. Both are the best RC's i have owned. Fast, very tough and easy to maintain. The only thing that is really starting to anoy me are the rear hub inner bearings.
After 2 to 3 packs i have to replace them otherwise they get stuck and destroy the hub. The front ones last for over 20 packs. I know the rear ones are more stressed but it's no fun anymore. I have found multipule threads in different forums about this problem.

So i started to investigate what the problem is. I first made an outer protection but it made no difference:

20171128_204235.jpg


When i was cleaning the hubs yesterdey i noticed the inside of the hub and bearings is full of sand.
So i started to investigate why and figured the problem is in the wheel axle. The slots in which the dogbone moves are too long and stretch beyond the bearing. Thats where all the sand comes in:

20171221_173630.jpg

20171221_173712.jpg

20171221_173752.jpg

The sand gets behind the bearing and is pushed in. The front CVD's do not have this design, they are closed, so i think that's (also) why the front ones last much langer.
Now i am trying to find a solution. I have tried to close the slots with heatshrink tube:
20171221_181327.jpg


It doesn't really feel like a solid solution.
I thought of placing CVD's in the back, but that's an expensive solution if possible. Maybe some kit or shoegoo but i doubt that's going to last. There is very little space between the bearing and the hub so the options are limited.
Does anybody have an idea how to fix this for all Arrma enthousiast facing the bearing problems?

Thanks!!
 
Are you using sealed bearings? If not, those will likely take care of it.

Another idea... is that exposed portion of the dog bone slot needed? If not, it would be pretty easy to fill it from the inside to plug up the gap. There are a ton of ways to skin that cat but I am thinking a 3D print would work great right there as long as it doesn’t get too hot.
 
Dude this explains so much, my rear bearings would always be full of crud after a run but the fronts would be fine.

@Dustin Mustangs if you look at the one picture you can see the blue seal on the bearing.
 
What the hell, I was always told that the front cvds didn't work.
 
I ran the truck with the front drive shafts in the rear and it seems to run fine. The only issue I see is lifting the rear a arms creates a little binding near the differential cup. Depending on who you are that might not be okay.
 
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Yeah it's really close but in the end I definitely think a millimeter or two at the most on the axle shafts will probably be helpful. There's got to be some other brands that are Tad shorter that would work.
 
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Never worked on any other arrma vehicles. Is there one that might have a hair shorter cvds? Or shorter out drive cups from the diff. I do remember somone one here using the light weight losi out drive cups. If they were a bit shorter you would have plenty of room.
 
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The Typhon front CVD's don't fit. I think the Kraton works because they are almost the same length as the dogbones.
Back to the Typhon: the diff outdrives have sort of a stop. What if we use a dremel to remove them so the CVD's fit?
20171222_215827.jpg
 
They look like they don't stick out as far. Talking about the shaft that starts at the bottom of the cup and goes into the differential to the pin. Would be interesting to see that outdrive cup next to a kraton outdrive cup. Might just be the picture or the fact that I've been staring at my kraton for too long. But the shaft itself looks to be shorter. The only thing I own at this point from arrma is a kraton so I really wouldn't know.
 
Nobody seems to agree, are they bad?
Re:Hot Racing I have a pair I'm pretty happy with on an ECX truck but it's their most expensive model (spring steel and stuff) and I've had the cheaper ones fail quickly.
Does anyone make good cvds?
 
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