Kraton Diff Cups hitting lower arms

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.

RC_Noob

Active Member
Messages
225
Reaction score
244
Location
SoCal
Arrma RC's
  1. Kraton 6s
Just noticed while cleaning the rig (kraton 6s V5 RTR) some divots in the lower arms from what it looks like the cups hitting it.

2.jpg


Both the front right and left arms have markings like that, but the rear does not. Why only the front and not the rear? And, how do I stop/fix this from happening?
 
Oh ok lol. I saw that and thought something was either broken or bent lol. Would love to know if there is a way to stop that from happening though.
Think some guys put plastic spacers on the shock shaft to keep them from compressing all the way. Or something like fuel line too I've read.
 
Axial AXA1358
Oh sweet there we go! Thank you!

Edit: Curious though, the front shock shafts are 4x62.5mm, these axial shock dampers are 3x7x8mm. I know im a big noob to all the measurements and what not but, are the right fit? If so, someone edumacate me on how to read the axial one. I just assumed its inner diameter, width, length.

 
Last edited:
Oh sweet there we go! Thank you!

Edit: Curious though, the front shock shafts are 4x62.5mm, these axial shock dampers are 3x7x8mm. I know im a big noob to all the measurements and what not but, are the right fit? If so, someone edumacate me on how to read the axial one. I just assumed its inner diameter, width, length.

You are right in your assumption about the dimensions of the Axial part.
But the dampers are made of silicone or a similar soft rubber type material, so you can still easily push the shock shaft through.
 
You are right in your assumption about the dimensions of the Axial part.
But the dampers are made of silicone or a similar soft rubber type material, so you can still easily push the shock shaft through.
Ohhh ok, perfect! Thank you for clarifying it all!
 
At some point I am going to need to try this.. Why didn't Arrma just design the shocks a little differently?
 
Last edited:
Just noticed while cleaning the rig (kraton 6s V5 RTR) some divots in the lower arms from what it looks like the cups hitting it.

View attachment 276835

Both the front right and left arms have markings like that, but the rear does not. Why only the front and not the rear? And, how do I stop/fix this from happening?
Have your driveshafts ever popped out? (but the look of the diff cups, i'm guessing yes)

That issue isn't from the diff cups rubbing, it happens when the driveshafts pop out while you're driving or if you keep driving after they pop out. If the wheels are rotating the dog bone pin is going to keep rotating too. So the pin digs into the a-arm as it spins around.

And that looks pretty tame. Mine are much worse ;)
 
Have your driveshafts ever popped out? (but the look of the diff cups, i'm guessing yes)

That issue isn't from the diff cups rubbing, it happens when the driveshafts pop out while you're driving or if you keep driving after they pop out. If the wheels are rotating the dog bone pin is going to keep rotating too. So the pin digs into the a-arm as it spins around.

And that looks pretty tame. Mine are much worse ;)

They have popped once or twice (same ones in the front) a few months ago. Thats where I originally noticed the cups were mangled up pretty bad. So I got the M2C ones and installed those. The picture I posted is an m2c cup and even that one is a little chewed up. What i find odd is that the rear ones, the arms and cups are in absolute pristine condition and I don't know why its so vastly different between the rear and the front.
 
I am glad I opened this thread. I had bought some other Axial bump stops recently but was looking for other options and this thread delivered big time. I assume these will likely need to be stretched as well. I bought them for my Slash/Rustler cars but was hoping I could use them on the 6s Arrma cars also.

These are somewhat 'squishy'. I measured with my digital calipers and got 8.9 mm H x 9.6 mm OD x 4 mm ID. If I put the flats in my digital calipers to measure the height I can 'squish' it down to 8 mm with a bit of thumb pressure. It takes a good bit of pressure to get it down to 7.2 mm.

2023-02-09_13h44_06.png
 
What i find odd is that the rear ones, the arms and cups are in absolute pristine
The front ones are more troublesome because there's more movement or articulation..ie: the steering and the shocks. So they pop out more often. Especially if you use rpm arms on the 6s and 8s platforms because they are more flexible. I'm dealing with the same problem on a brand new build I just finished. First run yesterday, the left front lower arm popped out after a mild cartwheel. I will either modify somehow or put the stock front arms back on. Oh yeah...that happened to me with ZERO shims on the pillow ball end of arms.
 
Aren't there dogbones that are a bit longer so they are less likely to popout? I've watched so many rc videos in the past year and a half I can't nail down which rc that was for lol.
 
Old Thread: Hello . There have been no replies in this thread for 90 days.
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.
Back
Top