rgh0 wrote:Also live axle cars have a larger oil amount in the live axle
Not true. A live axle car is not filled to a level that includes oil entering the axle tubes.
rgh0 wrote:hanging down below the car rather than being set up in the chassis
Maybe true - although probably only an issue under race conditions when circulating oil through a separate cooler may be a better option. A Lotus Elan is a light car (lighter than the Fords the axle was designed for) which does help lessen the loading on the gears.
rgh0 wrote:
"Sealed for life" for most car manufacturers basically means you do not have to change it during the warranty period, what ever that meant was back then, and what ever it is now for new cars.
Having worked for two vehicle OEM's I take offence at this because that hasn't been my experience working in the automotive industry. Most if not all manufacturers take their reputations very seriously with decisions (engineering related ones at least!!) made using deductive reasoning and empirical data based evidence.
rgh0 wrote:I have also drained lots of diffs that have used traditional group 2 mineral oil like Castrol EPX 85W-90 or its older equivalents for many years and generally it comes out "black" and smelling "burnt"
Yes it always comes out a dark colour but this is subjective and not evidence that the oil has actually failed in its ability to perform it's function and adequately lubricate.
rgh0 wrote: I don't use mineral oil based lubricants because I use my cars harder than most and do more miles than most and have been doing so for 40 years and I see synthetic lubricants as clearly superior
May or may not be true in an automotive axle never designed for synthetics and not being extended well beyond it's original design intent. It's true that OEM's are canny and won't spend extra money if there is no able to be realized benefit in doing so.
Jeez - I reckon there's definitely some secret ingredient "smelling salts" that Redline put into their products judging by the passions raised whenever any discussion comes up about them!!