10-09-2020, 08:00 PM
SAE 90 gear oil is about the same as SAE50 engine oil, which is about the original recommendation. Thick oil saps precious power.
In the 1960s some vehicles recommended SAE 20 for gearboxes but this was reckoned marginal for towing cravans out of the Grand Canyon in summer.
In the 1960s some vehicles recommended SAE 20 for gearboxes but this was reckoned marginal for towing cravans out of the Grand Canyon in summer.