Differential Oil requirements

[pjdemmitt]

What differential oil to use in '88
<hr style="color:#cccccc; background-color:#cccccc" size="1"> I have an 88 5-speed with a diff making horrible noises when going around turns and a whining noise when accelerating in any gear. The car has just 65,000 original miles and recently had the transmission and differential oil changed. A friend who used to work on Toyotas told me that the noise could be caused by improper oil being used in the differential. The place I took it for service may not have known of any special oil requirements for a car this old and just put a generic grade in. My friend said that there is an additive that should be in the oil. Does anyone know what this is and where to get it?

Any information on what I actually should use and where to get it would be really helpful.

Thanks in advance for any help.

Paul