19-10-2017, 09:08 PM
For car synchro boxes all makes, generally engine oils were often recommended, commonly 30, and when stable multigrades superceeded, this typically became 20/50. Both have been detergent since the early 1950s.
But for more consistent synchro operation, since the 1980s the specialised manual gear box oils have become more normal recommendation for new vehicles.
Abrasive (as distinct from fatigue related) wear in a Seven box is negligible on original pre war non additive oil, and all conventional oils now include anti wear additives.
For older cars consideration of noise and leaks were a major factor in oil choice.
But for more consistent synchro operation, since the 1980s the specialised manual gear box oils have become more normal recommendation for new vehicles.
Abrasive (as distinct from fatigue related) wear in a Seven box is negligible on original pre war non additive oil, and all conventional oils now include anti wear additives.
For older cars consideration of noise and leaks were a major factor in oil choice.