Avoiding Crunching First Gear - Is there a technique

[Bob Culver]

Choice of gearbox oil was determined largely by consideration of noise and leaks. A thin oil assists synchro but may slow crash changes. Until recent times an engine oil, including multigrades, was the common recommendation for very many cars. Unless perhaps of the classic type, such oils contain anti wear additives not present in the early 30s. The "crossover" temp where 20W50 is thinner than 30 is way below everyday temps. Moderns with enormous power have gearboxes sized much as the Seven so Seven lube is not critical.

[Mike Costigan]

I've always followed the Austin Motor Co's recommendation, which was to 'use regular engine oil and under no circumstance use a heavier grade'.

[Parazine]

I've always followed the Austin Motor Co's recommendation, which was to 'use regular engine oil and under no circumstance use a heavier grade'.

+1. Has served me well for the last forty-five years.

[Michael D]

This topic causes me to raise the question if Millers Classic Mini Oil (https://www.millersoils.co.uk/products/c...l-20w50-4/) would be a sensible alternative. This has been developed to be used in both engine and gearboxes and should therefore posses similar properties as advocated here; 'use engine oil' .... As since a fried of mine had a leaky gearbox on a long distance rally several years ago, I'm one of the prudent kind so I tend to carry small canisters of oil not only for engine but also for gearbox and diff.... if I can resort to one kind that will fit all that would make life a lot easier (and less weight to carry)

[Bob Culver]

This is straying into well worn territory. Fancy oils in stock Sevens reminds me of an engineer here who got into serious trouble for stating that using CNG for power generation was "feeding chocolate to pigs"". Reinforces the case for a simple no frills no fads guide to running a Seven.
re Ruairidh's comment, the conditon of the splines is a topic whcih receives inadeqaute mention. If a step has formed inside, the problem can arise. And worn splines lead to clacking noises at low speed in top.

[Colin Reed]

HI All,
I am with Terry on this Oils have moved on and developed 75/90  are for gears and the seven will benefit 

Colin 
NZ

[Mike Costigan]

Modern gear oils may be fine for the gears themselves, but what about the bearing?


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[Nick Turley]

My gearbox gets EP90 and runs well after 87k miles of use.

Millers chemist recommended such use to me 30 years ago

It is incorrect, as I am sure most know to think that EP oils dissolve brass and bronze, this has been the case since the advent of GL4 and Gl5 spec oils (a long time).

The wear factor of such oils in gearboxes and back axles is much reduced.

[Bob Culver]

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.

[Chris KC]

Engine oil.
And no heavier than SAE 30.