Kraton EXB Roller - One diff clearly not new?

[Twitchfast]

Long story short, I bought a brand new EXB Roller for my Dad and with every RC I purchase, I always tear the diffs down and thicken up the diff oil/shim where necessary.
Front and centre were perfect, diff oil ran clear and nothing had any wear on it.
Upon opening the rear diff I was concerned by the black silicone oil as shown in the attached files
Further disassembling the diff shows wear on the limited slip parts, has anyone else experienced this? I'm completely at a loss because the box was sealed and the entire car looks pristine.

Spoiler

I have no photos of it, but the plates behind the planetary gears had wear, including the shafts the gears spin upon.

 

[Sandracer_NL]

The LSD plates have a smooth and a non-smooth side. Judging from your pic I wouldn’t be concerned, maybe they did a short test run with a tight shimmed rear diff.
Not sure which oil they used, but it looks really black.

 

[Twitchfast]

The LSD plates have a smooth and a non-smooth side. Judging from your pic I wouldn’t be concerned, maybe they did a short test run with a tight shimmed rear diff.
Not sure which oil they used, but it looks really black.

The black oil was what made me bother to look for more signs of it being used, front and centre were clear as you'd expect.
The shop I bought the roller from just got back to me and will be sending out replacements, they contacted Hobby Horizon who appear to be shirking responsibility on the matter.

 

[JustAnOutcast]

Definitely looks used. No other way to explain wear on LSD disk and back of the larger planetary gear. The dark oil is a mystery too.
I didn’t check my diffs before running, but those wear marks on the LSD star disk look about like what I found in my center diff after running eight packs or so. Dark oil is similar too. From what I noted during first tear down, front and rear showed very little signs of LSD wear.
Glad your shop is sending a replacement.

Keep us posted if you learn more…

Just curious, what oil weights do you usually use for LSD diffs?

 

[Twitchfast]

Definitely looks used. No other way to explain wear on LSD disk and back of the larger planetary gear. The dark oil is a mystery too.
I didn’t check my diffs before running, but those wear marks on the LSD star disk look about like what I found in my center diff after running eight packs or so. Dark oil is similar too. From what I noted during first tear down, front and rear showed very little signs of LSD wear.
Glad your shop is sending a replacement.

Keep us posted if you learn more…

Just curious, what oil weights do you usually use for LSD diffs?

This is the first Arrma LSD diff I've had access to so this is purely experimental, personally I opt for heavy weights as I'm not racing and I do my utmost to keep tyres on rim without compromising on speed/power.
500k front, 1m centre and 100k rear is my go-to, that's how I ran my Typhon and my 1/5th scales.

Once the replacements have arrived, I'll be giving the shop a glowing review since I'd like to reward those who look after their customers.