GM has TSB's that state you cannot use synthetic gear oil in diffs that use RTV for the gasket. How does a synthetic oil break down RTV when a mineral oil doesn't??
GM Diff Question
- Thread starter touringt14
- Start date
- Status
MolaKule
Staff member
It doesn't according to my tests since cured RTV is very inert.
Here is the problem; too many mechanics get in a hurry and pour the oil in the diffy before the RTV cures. Some synthetic base fluids might affect the RTV before it is cured , but not after.
My solution is to always place a thin coat of RTV on the composite or paper gasket before application, then let cure before adding lube.
Here is the problem; too many mechanics get in a hurry and pour the oil in the diffy before the RTV cures. Some synthetic base fluids might affect the RTV before it is cured , but not after.
My solution is to always place a thin coat of RTV on the composite or paper gasket before application, then let cure before adding lube.
- Status
