Notorious My diff case metal bit is spinning freely - replace?

[Eno]

I am rebuilding my recently bought Notorious 6S. To my surprise all three diffs were filled with grease .
I have noticed that on 2 of the 3 diff cases the metal part has become loose and is now spinning freely.

Would you guys replace these cases?

 

[SrC]

Can you be more specific. Maybe a few pix??
I am 100% sure we can square things away for you. You just might need more parts than you think TBH.
BTW, JennysRC.com is a great inexpensive solution for all Arrma parts. Depends what you need.
Did you buy this brand new? Because Arrma never used" "Grease" inside any 6s diffs at all. Ever. These diffs only use Diff Silicone OIL. Nothing else.
You might be looking at Proper Differential "Oil" that has become Dark sludge/ paste, from a completely neglected or worn out diff(s). With future replaced diffs Make sure to run 60k front/ 500k center and 20-30k Rear CST diff oils. Diffs will last way longer and will drive way better, coming alive when you put the power down. Make sure to refer to your manual. Or find it online at Arrma-RC.com. The Manual is your bible.
Knowing the nomenclature of your parts will help describe to us your issues better. There is a maintenance interval for maintaining your diffs. It's all in the manual.
Send us pix to start out.

 

[Eno]

Ok so it wasn't grease but old oil. Truck was bought used.

Here you can see the metal bit I was referring to. I can even press it out of the case.

 

[SrC]

What I thought
Question: Is this the Center diff?????

If so, I would buy this "Metal" center diff as a replacement.... but empty out the oil well and put in 500K CST oil.

https://jennysrc.com/collections/fi...-50t-spur-gear-ara7618?variant=39857937809462

If this is the Fr or Rear diff, get this, with the standard plastic diff cup. Better to use the metal diff only at the center, as it gets super Hot and fails for this reason. This below is the complete diff with Bulkhead. Again, Don't use the stock oil that is in there. Run 60k oil if the front and 20k or 30k in the rear diff.
Buy oil to have on hand for this and in the future. This is a must have when owning these 6s rigs. I use these oils generally in most of my 6s rigs. Specifically my Notorious and 6s Kraton, the exact oils I stated above. Most of us here at AF run these type oils with standard Open diffs. Any brand of diff oil. Doesn't matter. Silicone oil is all the same. Except for how Thick they are.

https://jennysrc.com/collections/ar...ferential-front-rear-outcast-kraton-ara8611v5

I have been through the same damage long ago and even worse. With a completely Melted center diff. It was a lump of plastic and metal. All toast. They can shoot up to 250F+, especially with the thin stock 100k oil in there. You are not alone.
The stock oils front and rear is only 10k cst. Center is only 100k. All too very thin. The main problem here when bashing these fast and hard. They "diff out" like crazy.

 

[Eno]

Thanks for your input, @SrC
The broken diff cases were the front and center ones. It's funny but I already changed the center diff on my Mojave to the ARRMA metal one after reading a post of yours. Same with your diff oil recommendation - I did put that info into a text file (like I usually do) and ordered the oils a couple of days ago.

 

[SrC]

Yeah , you got this for sure.