Kraton METAL DIFF CASE #ARA220050

[Kingpin]

Man I have a lot of reading to do about these diffs. It seems like there are different answers for each diff setup depending on the optional parts you are using.
I have the Arrma aluminum diff cases and 3 sets of Mugen diffs to assemble.
Looks like it will be a fun time figuring it all out.

 

[5AFE CRACKER]

I just finished redoing the centre ?didn't end up wasting and fluid I was lucky I was able to remove the spur gear side take out the planetary gear insert the shim reassembled and because with the ARA220050 metal diff case you can also remove the other side I did the same thing then used blue lock tight on all 8 screws and tightened it all up now I'm working on the front just got done removing the diff added fast eddy bearings and while I had that all torn down I was also able to install the 4 small steering rack bearings and got rid of those useless brass bushings and also installed new HR front shock tower man this is work lol

 

[fpvmiller]

@crimsonfancy so sorry to hear of your issues. I am willing to bet you got a hold of a bad cup set. Since I have gone through 12 with no issues I would say try one more time with a new cup.

@Rcproponent I don't doubt your 2-1-2-1 shim requirements. You used the mugen shims and I'm sure the thickness may be a bit different. Again though, dry assembly and test is always best. My position is if I shimmed the planetary gears it essentially pushes the planetary on both sides closer to the satellites which in turn would push the satellites outward when they are compressed between the two planetary gears. As long as the satellites (and the whole diff internals) don't have any movement and are still "loose" enough to spin freely however many shims you use wherever is what works ?

 

[crimsonfancy]

@crimsonfancy so sorry to hear of your issues. I am willing to bet you got a hold of a bad cup set. Since I have gone through 12 with no issues I would say try one more time with a new cup.

@Rcproponent I don't doubt your 2-1-2-1 shim requirements. You used the mugen shims and I'm sure the thickness may be a bit different. Again though, dry assembly and test is always best. My position is if I shimmed the planetary gears it essentially pushes the planetary on both sides closer to the satellites which in turn would push the satellites outward when they are compressed between the two planetary gears. As long as the satellites (and the whole diff internals) don't have any movement and are still "loose" enough to spin freely however many shims you use wherever is what works ?

Well, I'm a loyal Arrma guy so I'm not here to be negative. I'm sure I got a bad part or a piece of a bad batch. I have a couple stock plastic diff housings still in the bag and will use those for now but I surely wanted to get rid of the tombstones and try something new. I could call HH and bet they'd send me a new one but I'd rather take it on the chin and carry on. Fortunately I have plenty options with diffs on the bench..lol. I hit Jenny's up for new ones more than I should just to keep a steady flow of switcheroos in times of trouble. While one is dead for rebuild I always keep a replacement. No big deal. ?

Man I have a lot of reading to do about these diffs. It seems like there are different answers for each diff setup depending on the optional parts you are using.
I have the Arrma aluminum diff cases and 3 sets of Mugen diffs to assemble.
Looks like it will be a fun time figuring it all out.

Kinda gotta feel it out for shims. What works for one truck may not work for all. At least this is what I've learned and the more I do it the faster I get changing out. Tickle it and adapt is my philosophy. ?

 

[Spikeyboy]

this may help:

 

[fpvmiller]

In that vid is exactly what I have described here in this thread. Except I personally don't feel the need for extra shims on the satellite gears. The way he tested for slop was with an open diff. I test with a closed dry diff. The feel with slop is similar to what the pinion and spur feel when you are setting mesh. Or to put it another way if the diff is closed dry and you try to rotate the outdrives and it feels like there is just a bit of a lash then shim.

When I say lash I mean when you rotate the outdrive on one side and there is a feel of a "gap" between when you turn the outdrive and the gears engage. That's lash. You would shim that. On the aluminum case because the tolerances should be tighter and the fact that the case itself is smaller (no tombstones) it actually goes together tighter overall. I personally have one shim on each satellite and my 3 rigs now are all smooth running. I have even run 3.8 tires on my truggified typhons with my aluminum diffs with no signs of issues. But others do have their preferences after all.

 

[Spikeyboy]

I also checked with the diff closed when i did it all up and ran it dry - wasn't to tight so left the extra shims in, if it had been tight i would have removed. Based on my experience when the satellite gears can move inside they generally need an extra shim.

The one i have in the front didnt need any extra shims

Of course your more than welcome to spend the time and effort doing a video if you want ??

 

[fpvmiller]

It's faster to type it out than make a vid ??

 

[Kingpin]

I'm not even gonna put the diffs in.
Shelf queen FTW!
jk