Hi all, I have 3-4 year old unopened royal purple 75w90 and Mobil ATF sitting in my garage from my 91 XJ. I want to change my diffs and transfer case fluid after work but I want to confirm these are 1. not to old, 2. still the correct fluid for my 99'.

I have read mixed reviews on the type but most say unopened bottles shouldn't be a concern unless they are very old.

Cheers

 

The oil is actually millions of years old. A few extra years sitting on your shelf isn't going to hurt it.

 

Like Firestorm said. It won't break down in a sealed container.

 

Make sure it's dex/merc III and not ATF+4. Our trannys don't like the synthetics.. Assuming it is an AW4

 

I'm not replacing the tranny oil, only the transfer case and diffs. I am using the Mobil ATF in the transfer case.