posi rear questions

[chris71]

ok, 1971 C10 3.07 posi 12 bolt, 5 lug....

1) there is a bunch of crud on the gears in the carrier, not much, nothing excessive, just needs cleaning. can i use brake cleaner to clean it out good? will this hurt the posi clutches or bearings or anything?

2) just got this rear, havent put it in yet, is there a way that i can see if the clutches are worn or bad without diss-assembling the carrier?

3) on the bearing surface of one axle there is rust pitting, not surface rust but pitting, it covers about 50% of where the bearing rides on (sorry no pics) is this axle toast? i assume it will tear up the bearings which lead to problems.

4) how much scoring or wear is acceptable on a set of axles (where the bearing rides). any is bad? 5 thousands? 10 thousands? any help here would be helpful.

5) a few ring gear teeth and planetary gear teeth have similar pitting on them, on th ering gear teeth only like a third or a quarter of each tooth has the pitting, the planetary gears maybe 50% to a third of each affected tooth has rust. how long will these gears last?

thanks in advance