Kraton Additional 4s Drive cup attachment point

[VDVC-RC]

That's a socket head screw attaching the inner CVD cup to the diff

Any particular reason why ARRMA or the aftermarket didn't use this attachment point on the 4s line?
They used it on the 3s with the old U-Joint style axles. On the 4s it seems like it's a bit of added security in addition to the grub screws.

 

[MrTitanium]

Both fasteners have the same purpose. I prefer having a screw attach at the center of the outdrive with a dab of Loctite.

 

[VDVC-RC]

Yeah, I wish the aftermarket 7075 aluminum ones had this attachment point built in.
I just drilled/countersunk this one freehand & it seems to work out OK.
Haven't tested it at all because I broke another slipper.

 

[MrTitanium]

Yeah, I wish the aftermarket 7075 aluminum ones had this attachment point built in.
I just drilled/countersunk this one freehand & it seems to work out OK.
Haven't tested it at all because I broke another slipper.

Which aftermarket aluminum ones? Are you taking about outdrives? Aluminum wouldn’t last very long at all as the teeth would shear off.

I run the steel aftermarket ones.

 

[Surchaufeur]

Its harder to access. Because of the crappy design they went with over the CNC machined option they had

 

[neighborhater383ci]

That's a socket head screw attaching the inner CVD cup to the diff

Any particular reason why ARRMA or the aftermarket didn't use this attachment point on the 4s line?
They used it on the 3s with the old U-Joint style axles. On the 4s it seems like it's a bit of added security in addition to the grub screws.

View attachment 363538

Gpm utilized it on the 4s v2 driveshafts they make in addition to the grubs

 

[Dales396lt4]

I have the mad labs RC axle kit and I’ve been using the center screw to hold them on as well as the grub screw for three or four months now they work great however, I’ve been breaking out drives lately. I also upgraded to the 2.5 center differential. For some reason, I’ve been breaking teeth off of the center differential. It works great but breaking teeth is downtime and the gears are expensive. One more thing is that my K4S V2. Is now heavier than my K6s EXB RTR.

 

[neighborhater383ci]

I have the mad labs RC axle kit and I’ve been using the center screw to hold them on as well as the grub screw for three or four months now they work great however, I’ve been breaking out drives lately. I also upgraded to the 2.5 center differential. For some reason, I’ve been breaking teeth off of the center differential it works great but breaking teeth is downtime and the gears are expensive. One more thing is that my K4S V2. Is now heavier than my K6s EXB RTR.

What center diff fluid are you using? If you’re breaking rear out drives I’d loosen the center up or if you have heavy tires change em, also if your grubs come loose and allow the shaft to wiggle on the out drive they snap too

 

[Dales396lt4]

Those are all good points and things that I check out on a regular basis. I think the biggest problem is I run the truck a lot and it has a 6S power system in it. I normally only run it on 4s though, but it is a very strong truck. I run stock tires. I don’t remember off the top my head but I think the center diff fluid is 500 K. As for rear drive cups, I don’t think it really matters. I’ve broken all of them at one point or another. I’ve just been replacing them with aftermarket. You know the deal bash crash rebuild.

 

[neighborhater383ci]

Those are all good points and things that I check out on a regular basis. I think the biggest problem is I run the truck a lot and it has a 6S power system in it. I normally only run it on 4s though, but it is a very strong truck. I run stock tires. I don’t remember off the top my head but I think the center diff fluid is 500 K. As for rear drive cups, I don’t think it really matters. I’ve broken all of them at one point or another. I’ve just been replacing them with aftermarket. You know the deal bash crash rebuild.

I have mine on 8s granted it’s a speed build so it’s not got heavy tires but my bashing/ power getup is the gpm axles, checking diff cups to make sure they’re not loose regularly and not landing jumps in the throttle. I occasionally break the cv joint pins but they’re so easy to replace and cheap that they’re a great “weakest link”

 

[PittsburghJason]

I have the mad labs RC axle kit and I’ve been using the center screw to hold them on as well as the grub screw for three or four months now they work great however, I’ve been breaking out drives lately. I also upgraded to the 2.5 center differential. For some reason, I’ve been breaking teeth off of the center differential. It works great but breaking teeth is downtime and the gears are expensive. One more thing is that my K4S V2. Is now heavier than my K6s EXB RTR.

You can try a hardened steel center diff gear. I installed this one after my teeth stripped.
https://www.amazon.com/dp/B0CR7V6RQL?ref=ppx_yo2ov_dt_b_product_details&th=1
https://www.gpmparts.com/arrma-moja...pur-gear-57t08-mod-gpm-mam4057ts-p-33690.html