Transmission and differential storage

[Mike B]

This may be a dumb question, but do you need to do anything to prep a transmission or differential for storage (months to a year or more)? Both have been removed from operating cars and have had the oil drained. Should they be stored filled with new oil? I bought a can of Sta-bil fogging oil and was considering using that instead of filling them with oil. Has anyone used that before? I read on HybridZ that someone sprayed the interior of a differential with WD-40 and opened it later and it was completely rusted inside.

-Mike

[geezer]

That's not a dumb question and there are many of us that are storing diffs & tranys that could use some guidance. I remember seeing pics of spalled bearings said to be caused by long term storage. It was clearly evident in the pics where there was an actual line defining the portion of the bearings that were above the oil level and had dried. This caused a "leading edge" to be formed on the bearings sufaces, that lead to failure.

I suppose that a teardown, inspection and rebuild is the best course of action after long term storage, but in reality, this isn't always done. Rotating the entire assembly occasionally may help keep surfaces coated. I might be wrong but I don't see any benefit of changing the oil before storage. It is not like crankcase oil that becomes corrosive from the effects of combustion.

Edited April 12, 2009 by geezer
Corrected sentence