Ayk Diff advice needed.

[Dadio]

Hi guys and gals , I need people's views on something .
I just found a broken tooth on one of my Ayk Bobcats diff gears , it's just one half broken tooth on one of the plastic sun gears or the gear that is fixed to the out drive .
So I duly tracked down one of the later metal gears sets, these have both alloy sun and planet gears , it's arrived bnib .
My question is this , do I
1 use the complete replacement diff set or
2 use the metal sun gears and the original plastic planet gears .
The reason I ask is that alloy on alloy gears might wear more quickly than a mix of alloy and plastic .
What do you think ? I'm inclined to mix metal and plastic .

[jwscab]

if the diff is open with no way to seal it, i'd go plastic/metal provided they match/work together. if the diff is a sealed type unit and you can run some diff lube in it, i don't think it will matter.

[Dadio]

It's open , it's from 1985 , I don't think sealed diffs existed back then but I'm often wrong , I can grease it but there's no way of trapping the grease or an oil in place , the gears are exactly the same and mesh well together so I think we agree that plastic/metal is better than metal/metal especially 1980,s era diff gear alloy , if it was modern high grade metal diff gears I'd be far less concerned .
Thanks for the reply .