Whenever I had water sucked in the rear diff
(on my 87 toy pu and 88 4rnr), it was obvious,
due to the water turning the fluid mud color...
So open up you diff, and stick a probe (finger)
in and look at a dab, if its clouded/tan color,
and not see thru, then it's time to change the
fluid out...
If it's dark and see thru, like gear is new, like
syrup, then you are fine...
Also take note on any granular or metallic type
particles, this is not a good sign...
