What parts should be replaced in a Q45 differential

[Infinitiguy19]

I have a spare TCS differential from a 1991 Q45 and the oil and magnet were in fair condition (Meaning not to dirty). Now I want to replace all the parts that need to be replaced to have a good spare one.

I also pulled the cover off (WHAT A f***ING b****), Apparently a hammer and aluminum don't mix so the cover is trash (I think I am the next white Jesda because I do have a Green (DJ2) 90-93 Q45).

So I know the Viscous coupling obviously needs to be replaced but what else?

The ring and pinion according to my dad are like brand new.

Pictures will follow as soon as my body heals (Dragging the b**** up and down stairs takes a toll on your body AFTER a day apparently).

I also have a spare torque converter (Thanks to Johnny Rocket backing out of a deal). But I don't even know what I am getting into there.

[Q451990]

I don't know of many people that have done a whole lot with the differential other than replace it as a unit. Not to say that it can't be done, but it's sort of like rebuilding a power steering rack - lots of tight tolerances and cheap parts but a real pain to get right reliably.

Heath

[DrewQ45]

Paul, as long as it turns smooth as silk with no sign of the chalkiness, then you should be good. I've replaced a few of these and learned the hard way ($$$) how to pick out a good one.

[Infinitiguy19]

The viscous part that needs replacing on the differential isn't available stand alone and is not cheap either. So I am with Drew on this one: Pick only good differentials from the junk yard.

[Trumpkin]

may as well throw a 300zx na 408 in the case if you have her apart.

[elwesso]

i wouldnt necessarily say the viscous unit is trash, however i would definitely replace the bearings..

Im sure with regular fluid changes there are some diffs that have 250k on them and they still operate fine.

[Q45tech]

O replaced my diff at 220k and about the longest I've seen them stay quiet is 250k.................the viscous had long since died.Much depends on maintaining driveshaft and diff mounts so vibration does start and take out input bearings.

[elwesso]

I wonder how the viscous units out of a 300ZX or other nissan diff compare? My guess is they are the same?

[car nut]

So are the 300zx and Q45 pinion gears interchangeable?