I believe the service manual says it's just suggested to check it. Here's a vid of the oil (click image).

 

I changed mine at 39k it was very clear and the plug had almost no buildup on it.

 

is that whitey milk stuff in it? I.e. water?

 

Yes it is white milky stuff. I doubt it's water, probably just reactants from oil breakdown. As far as I know the oil is the original factory fluid. I replaced it with Lucas diff oil.

 

I never changed mines, i'm currently at 90k miles.. I guess i need to do mines asap.

 

I bought my car with 52K miles and apparently the guy lied about doing the maintenance... which I found out when I did my 60K maintenance myself.

The differential fluid was DARK and nearly black which a **** load of build up on the magnetic bottom plug.
Same goes for the tranny fluid.

90K is pretty bad... I hope you get it done soon so you don't face the same shock I did when replacing the diff. fluid!

Does anyone know what problems might arise from not replacing the diff. fluid?

 

Just an update, I think the synthetic fluid is causing a whirring when the fluid is cool. Will switch back to conventional soon and post the results.

 

Plz describe this whirring you are talking about. I used Mobil 1 synthetic and I actually hate there engine oil but there diff oil was good quality.