Typhon Typhon center diff cup replacement

[NewToArrma]

So I have to replace my center diff cup in my 2019 Typhon6s after about 5 packs, see pic below. First time I have taken a diff apart,lol. Was pretty easy to disassemble and cleaned everything, except o-ring, with brake cleaner. Time to inspect the bearings, shims, small and big gears. All looks good to me but I have limited knowledge on what a good vs bad shim looks like. Do the shims look good?

 

[PowerDubs]

Why did you take it apart to begin with?

I shimmed my new Typhon center diff with the new shims the other 6S cars show in the manual. But only because I broke it in a crash. The front and rear I will wait until they break to rebuild.

 

[NewToArrma]

Why did you take it apart to begin with?

I shimmed my new Typhon center diff with the new shims the other 6S cars show in the manual. But only because I broke it in a crash. The front and rear I will wait until they break to rebuild.

Had to replace my diff cup, see the first pic

 

[PowerDubs]

Ouch. What happened? Rock stuck in there?

 

[Notorious J]

So I have to replace my center diff cup in my 2019 Typhon6s after about 5 packs, see pic below. First time I have taken a diff apart,lol. Was pretty easy to disassemble and cleaned everything, except o-ring, with brake cleaner. Time to inspect the bearings, shims, small and big gears. All looks good to me but I have limited knowledge on what a good vs bad shim looks like. Do the shims look good?

Are all the new shims that come in the 2019 Arrma versions, curved like that?

 

[PowerDubs]

The deformation is from the outward force of the gears against them. All of mine has looked like that to various degrees... and all with very little run time. Even my brand new ran for 30 second Typhon.

 

[Notorious J]

The deformation is from the outward force of the gears against them. All of mine has looked like that to various degrees... and all with very little run time. Even my brand new ran for 30 second Typhon.

I'll see what my Mugen and Associated shims look like on the next service. My version didn't have shims from new.

 

[NewToArrma]

Ouch. What happened? Rock stuck in there?

Yeah, it was luck that I caught it

 

[Captain Dirt]

About the only thing I'd replace, other than the diff cup, would be the shims and put sealed bearings in. If the gears are in one piece and no teeth are chipped I'd still use them.

 

[NewToArrma]

About the only thing I'd replace, other than the diff cup, would be the shims and put sealed bearings in. If the gears are in one piece and no teeth are chipped I'd still use them.

I have some sealed bearings. I’ll replace the shims

 

[cootertwo]

All of this concave shaped shims is new to me. I've been into at least 4 or 5 diffs, and all mine were flat as a pancake.

 

[NewToArrma]

All of this concave shaped shims is new to me. I've been into at least 4 or 5 diffs, and all mine were flat as a pancake.

Factory shims?

 

[cootertwo]

I don't see how they can be that shape, when the 2 sides they wear against are flat ????

 

[NewToArrma]

So looking at the exploded view for my typhon V4 differential and it shows a shim between the ball bearing and the diff outdrive(X2), a shim covering the o-ring in the spur gear and a shim covering the o-ring inside the diff cup for a total of 4 shims. When I took apart my center diff I have none of these shims, only the 4 between the small gears and the part that hold the center pins.

 

[cootertwo]

Either Arrma is hand fitting these diffs, or just throwing parts together, willy nilly.

 

[Lazy Bushman]

Yep time for new shims. How are the speed runs going BTW?

 

[Notorious J]

So looking at the exploded view for my typhon V4 differential and it shows a shim between the ball bearing and the diff outdrive(X2), a shim covering the o-ring in the spur gear and a shim covering the o-ring inside the diff cup for a total of 4 shims. When I took apart my center diff I have none of these shims, only the 4 between the small gears and the part that hold the center pins.

Since you've been here a while, you've seen different opinions on the amount of shims needed for the 6s difs. Shims are tricky, as they can create a very nice snug fit, or they can create binding if over done. The tolerances are just so dam small. Is it possible that the factory makes the call at time of assembly? More for one, less for another? Some people who have older versions of the 6s have never added a shim, and claim that the difs work perfectly. Others say that different values are needed in different areas, depending on play. How many of us are qualified enough to make the determination on our own, based solely on feel? I did two new center Hot Racing cup difs, using the exact same shims in both. Once done, one seemed to spin easily in my hand, and the other was binding a bit. Now what. Which shim do I remove to stop the binding? Under the large planetary gear, or from the small satellites? It's crazy, but this is the name of the game, trial and error. Drive it, break it, fix it, and start over. That's my unofficial rc truck motto.

 

[Wmorgan]

I've recently been enjoying rebuilding my Kraton diffs due to some workmanship flaws but mainly my errors and shims looked similar. Replacing those with Mugen and putting on sealed bearings. BTW...I tried adding extra shims and once I screwed back together they would not budge...gears locked. So tried different combos and best was extra shim behind planetary gear but was still tight. Removed all extras and left Mugen and all is well. Just sharing my very recent, but intimate experience with my 2019 Kraton diffs and shims.

 

[cootertwo]

I think, like has been said before, it's best to assemble dry, (but with gasket), and try different shims, until you get it feeling right. Then fill with diff fluid and assemble. No speed runs here yet. Too damned hot down here in SW Florida! Heat index close to 100 most days.

 

[NewToArrma]

Since you've been here a while, you've seen different opinions on the amount of shims needed for the 6s difs. Shims are tricky, as they can create a very nice snug fit, or they can create binding if over done. The tolerances are just so dam small. Is it possible that the factory makes the call at time of assembly? More for one, less for another? Some people who have older versions of the 6s have never added a shim, and claim that the difs work perfectly. Others say that different values are needed in different areas, depending on play. How many of us are qualified enough to make the determination on our own, based solely on feel? I did two new center Hot Racing cup difs, using the exact same shims in both. Once done, one seemed to spin easily in my hand, and the other was binding a bit. Now what. Which shim do I remove to stop the binding? Under the large planetary gear, or from the small satellites? It's crazy, but this is the name of the game, trial and error. Drive it, break it, fix it, and start over. That's my unofficial rc truck motto.

You make a valid point regarding the factory making the call at the time of assembly what shims are needed. If that’s the case then you’ll probably see more and more V4’s with different amounts of shims from the factory

I've recently been enjoying rebuilding my Kraton diffs due to some workmanship flaws but mainly my errors and shims looked similar. Replacing those with Mugen and putting on sealed bearings. BTW...I tried adding extra shims and once I screwed back together they would not budge...gears locked. So tried different combos and best was extra shim behind planetary gear but was still tight. Removed all extras and left Mugen and all is well. Just sharing my very recent, but intimate experience with my 2019 Kraton diffs and shims.

I can’t justify paying $30 cdn for the Mugen shims, I just can’t. I’ll look for an alternative

I think, like has been said before, it's best to assemble dry, (but with gasket), and try different shims, until you get it feeling right. Then fill with diff fluid and assemble. No speed runs here yet. Too damned hot down here in SW Florida! Heat index close to 100 most days.

I plan on doing the dry assembly and test to make sure there is no binding.
So in order for me to get the factory planetary gear shims, it looks like I’ll have to order a diff gear set AR310436. Or do I order AR709024? Has anyone ordered ARA709057 factory shims?