It's tedious, but annual greasing lengthens component life

Low oil levels are common in gearboxes and rear axles

Check grease type needed; trunnions use oil for example

Limited slip diffs may require a special oil or additive

Steering boxes usually need a normal gear oil but check

Additves can be beneficial but only with a good oil

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It's vital to use the right grease if you want to keep your classic smoothly rolling along.

Further to our feature on Classic engine oils last month (back copies available), don’t think that the innocent tub of grease has been left in a time warp either. And as with engine lubricants, it’s just as vital to use the right grease if you want to keep your classic smoothly rolling along.

The role of grease hasn’t changed much over the years and chiefly it’s to lubricate a component where a normal oil is deemed ‘too liquid’ to serve as a lubricant. As with engines, higher speeds and hotter working temperatures meant more advanced greases had to be developed to cope, mainly to stop them overheating and melting under pressure from areas such as wheel bearing and brakes, the latter where the introduction of discs and their evolution really upped the temperatures.

Like engine oils, greases also have to meet certain standards and this is largely policed by the Lubricating Grease Institute (NGI) where a lettering system identifies its make up and constituency and since 1990 the US has tried to certify performance specs via its NLGI - National Lubricating Grease Institute - rather like oil API standards.

That said, you don’t need to ditch that half used tin of LM grease that you borrowed from your dad either as it will do the job as well as a ‘new’ tub. In fact, advanced greases such as synthetic types are largely unsuitable for motor vehicle use.

However all greases aren’t the same. As examples a Lithium based, high melting point grease is specifically designed as a wheel bearing grease for use over a wide range of temperatures where as a Moly grease is better served for king pins and bushes, shackles and suspension trunnions, bevel worm and peg steering boxes.

Grease can ‘separate’ in the tin and needs mixing, just a stir will do it before you use it.

TRANSMISSION OILS

As with engine oils, modern, finer tolerance transmission systems demand a new freer-flowing type of lubricant but unlike engine oils, a modern gear or transmission oil is quite okay for classic uses and this includes vehicles which previously used engine oils to care for the cogs. EP (Extreme Pressure) oils only appeared in the late 1950s which is why a good many manufacturers stipulated a straight engine oil before a gradual change over to EP 80 or 90. Since the 1980s there’s been a ‘multigrade’ transmission oil as well as a gradual switch to semi and fully synthetics which can have a working range rating of 75W/90, for example.

According to Miller Oils, there’s no reason why modern gear oils can’t be used in an MGB or Ford 2000E transmission and the lighter lube may yield a crisper change although noise levels may increase. On the other hand, older vintagestyle transmissions need specific oils for their internals; some old units with bronze bearings don’t like modern GL5 oils for example.

At the other end of the performance spectrum special high pressure oils are needed for limited slip differentials and one example comes from Castrol where its SAF-XJ is a fully synthetic 75W-140 hypoid gear oil, formulated for use in both conventional and limited slip differentials.

According to retailers we spoke to, classic transmission oils are becoming as popular as the engine types due to their specific nature.

ADDITIVE ADVANTAGES?

Oil additives is a hoary old subject because their use is as much down to emotion than anything else. There’s the age old argument of who is right; oil companies say that their oil are good enough already plus argue that an indiscriminate pour-in additive can upset the ‘balance’ of the oil. Additive companies counter this by claiming that the ‘brew’ isn’t strong enough to upset a base oil to which the oil producers retaliate by saying “so what’s their actual worth then?”.

We’re not going to enter into the argument except to say that in our personal experience additives have worked to a degree. Certainly when we tried Engine Restorer & Lubricant, marketed by Ametech (pictured right), in an old MGB some years back it did seem to run smoother and quieter for a while and we’re sure that many of you have tried additives in transmissions with similar effect.

What you shouldn’t do, unlike many motorists, is to use an additive as a substitute for a good oil to save a few quid - and even additive specialists will agree on this point.