[Rusty1]

I’ve searched all over the forum again and come up with some useful information and varying opinions regarding modern oils in older engines. On balance though these would seem like sensible choices for the engine/primary drive and gearbox on my bike. There may be better combinations available through experience on particular bikes but as I don’t know what oil is in mine would these make good starting points?

Thank you.

https://www.morrislubricants.co.uk/...ils/golden-film-20w-50-classic-motor-oil.html

https://www.morrislubricants.co.uk/...oils/golden-film-80w-90-classic-gear-oil.html

 

[Wishbone_09]

Don't see why not; but at this time of year a thinner winter grade 10w50 or 10w40 rating could be better to help cold starts, and maybe cheaper?

As for gear oil I would use a modern semi or synthetic also, they should exceed the original spec by a fair margin.

 

[Tritn Thrashr]

Is that gear oil safe for bronze bushes?

The engine oil will be fine.

 

[StuartMac]

Hi Rusty,

at this time of year a thinner winter grade 10w50 or 10w40 rating could be better

Nope, do NOT do this. Old Britbike machining and oil pumping is nothing like modern engines'. Stick to 20w50 or 15w50, buy the best you can afford - I use synthetic.

Otoh, one of the best things you can do for your T100 (any old Brit twin) engine is fit a full-flow filter. Make pot of tea/coffee and put "filter" into the Forum Search ... Fwiw, I use the Tri-Cor England one:-

http://www.tri-corengland.com/cgi-b...r&PN=Oil-Filter-Kit-pre-OIF-RS009.html#SID=15

... certainly on the T100, kit fits as pictured, in the space ahead of the battery behind the sidepanel. :thumb

Hth,

Regards,

 

[Rusty1]

Is that gear oil safe for bronze bushes?

Good spot, thanks, the data sheet says it shouldn't be used with older engines which may have bronze bushes. Mine does, the high gear bush. Back to the forum search/drawing board:smile2:

 

[Truckedup]

Gear oil that's ok for yellow metal comes up often in vintage car/truck forums.. But I have never seen any actual proof it corrodes bronze or brass.GL-5 is more "slippery" and can impair synchronizer ring action, but bikes don't have synchros....Does anyone have reliable info on the corrosion of metal parts? However, I do use GL-4 gear oil in my Triumphs just to be safe..

 

[Rancidpegwoman]

Hi Rusty
Oil Thread-that is a big can of worms that you have opened.

Looking at the Golden Film series of oils by Morris.

Firtsly the viscosity rating- the first number is the cold viscosity rating, the second is the hot viscosity rating.

While the cold rating can be varied within small margins- 10/50, 15/50 etc.

The second hot number can be considered a non variable, it is generally considered that any oil you choose should retain this rating. Our old air cooled engines run clearances and tollerances greater than modern engines, the thicker 50 rating accounts for this in multi grade oils. (Monogrades are a different subject).

The Golden film series is a low detergent oil. It does not have the additives that collect the combustion blow by carbon particles and wear particles and hold them in suspension. Instead, low detergent oil alows these particles to drop out of the oil and form a thick sludge at the bottom of the oil tank and in the crankshaft sludge trap.
This sounds bad, but it in fact the way our bikes were designed to work, we have no effective oil filters so the sludge effectively prevents these particles from being recirculated around the engine. This does mean that during oil changes the oil tank should be cleaned out and the sludge trap requires cleaning at regular intervals. (Requires complete engine stripdown)

However there is an alternative:

High detergent oils, as used in modern engines - these keep the combustion/wear particles in suspension in the oil, they form hardly any sludge, the oil tank stays cleaner and the sludge trap fills much more slowly. The downside is that these combustion particles keep getting recirculated around the engine, which is not desirable. Many owners that use high detergent oils fit after market oil filters to their bikes, these remove the undesirable combustion particles from the oil.

I think it is fair to say that most owners here use modern high detergent oils and an after market filter.

I will summarise the choices:
Low detergent oil, no filter, higher maintenance.
High detergent oil , aftermarket filter fitted, less maintenance.

One last thing, modern car oils have friction modifiers that play havoc with our wet clutches, an oil designed specifically for motorcycles oil is required.

Any oil you buy today will be a much better quality than the oils available when your bike was built.

Regards
Peg.

 

[StuartMac]

Hi,

Oil Thread-that is a big can of worms that you have opened.

Depends. Absent half-baked advice and counter-theory, at least the basics have never seemed particularly complicated?

Firtsly the viscosity rating- the first number is the cold viscosity rating,

It's also the viscosity of the base oil without any additive package. Main problem with SAE 10 and standard old-Britbike crank-grinding is the the film thickness is less than the height of many of the microscopic peaks and troughs in the journal surfaces, allowing the possibility of microscopic metal-to-metal contact.

Then there's the flow rate of even the best oil pump that can be bolted inside a Meriden twin's timing chest ...

Lastly here, although 10W40 and 10W50 were available when Meriden was still a relatively-large motorcycle maker, Meriden never, ever recommended a SAE 10 oil for standard road bikes.

modern car oils have friction modifiers that play havoc with our wet clutches, either an oil designed specifically for motorcycles oil is required, or as an alternative many people use automatic transmission fluid in the clutch chaincase

Errrm ... one of the earliest requests I made of Rusty after he joined the Forum was he add his machine details to his Profile, because the details would then appear by all his posts and help respondents give correct advice ...

'72 T100 is same as any late-'69-on Triumph twin - crankcase vents through the primary so the latter must contain the same oil as the engine. Then the long-known advice is to use only engine oil that has "JASO MA2" amongst the specifications listed on the container (for those that don't know, JASO is an umbrella standards organisation for six different Japanese makers' organisations all having something to do with internal combustion engine manufacture, MA2 is the standard that specifically excludes additives that cause 'wet' multiplate clutches to slip, JASO came up with the MA2 spec. when the SAE were being useless appreciating the problem).

Hth.

Regards,

 

[Rancidpegwoman]

'72 T100 is same as any late-'69-on Triumph twin - crankcase vents through the primary so the latter must contain the same oil as the engine. Then the long-known advice is to use only engine oil that has "JASO MA2" amongst the specifications listed on the container (for those that don't know, JASO is an umbrella standards organisation for six different Japanese makers' organisations all having something to do with internal combustion engine manufacture, MA2 is the standard that specifically excludes additives that cause 'wet' multiplate clutches to slip, JASO came up with the MA2 spec. when the SAE were being useless appreciating the problem).

Hth.

Regards,

Hi Stuart

You are of course correct on this, the shared primary/engine oil was on this model, I will make an edit to resolve this.

 

[Hermit47]

One characteristic of motor oils that's not been mentioned here is the percentage of zinc. I think it's fairly well established fact that high zinc content is good for old engines. For example, see

"Tech 101: Zinc in oil and its effects on older engines" https://www.hemmings.com/blog/index...zinc-in-oil-and-its-effects-on-older-engines/

For a list of common motor oils and their zinc content, see this link: www.hermit.cc/tmc/om/html/oil_z.htm

And, if anyone wants to get more technical about their motor oil, try this link: https://540ratblog.wordpress.com/

These links, and others, are available at: www.hermit.cc/tmc/om/manual.htm#crankcaselube

Gear oil that explicitly says it won't harm yellow metals is extremely hard to find. High sulphur content (what makes modern gear oils more slippery) seems to be a bad thing. I am actually doing an experiment with gear oils. I immersed some bronze parts in two different brands. This spring the parts will have been "marinating" for one year and i will remove them, measure the parts and compare them to "before" measurements. What's missing from my experiment is the heat and thrashing inside the gearbox, so I'm not sure how valid the results will be.

There are links to my gear oil experiment (complete with photos) and several other gear oil resources here:

www.hermit.cc/tmc/om/manual.htm#gblube

Cheers!

 

[rambo]

Use a modern 20/50 oil suitable for aircooled engines and a mineral GL4 EP80/90 gear oil and you will not go far wrong. I did have problems with GL5 synthetic gear oil by Mobil 1 ,with the second gear disengaging. Replaced it with a mineral gear oil after a week and the problem was solved.
Try OPIE oils in the UK who will have what you want and deliver free.

 

[StuartMac]

Hi Bruce,

percentage of zinc.

I suspect you mean the additive zinc dialkyldithiophosphate, (ZDDP to its friends)? Anyone believing it important could use a 15w50 or 20w50 with a SAE SG rating, (after SG, ZDDP percentage reduces significantly)? SG-rated oils aren't hard to find - "4T", "Vee Twin Oil", etc.?

When I was researching for my own information years ago, amongst others, I 'phoned specialist British blender Fuchs Lubricants (Silkolene is probably their most familiar brand to motorcyclists); not sure if it's still true but, in those days, if you wanted to ask technical questions about oil, an actual tribologist answered the 'phone. :thumb During a lengthy 'phone conversation, I was advised that there are several other chemical compounds that provide similar or better specialist lubrication than ZDDP and, if at least some of the other compounds are used, the oil can gain a later SAE rating, which can have other benefits over SG.

Gear oil
High sulphur content (what makes modern gear oils more slippery)

This isn't what https://www.widman.biz/uploads/Transaxle_oil.pdf says?

History:
The gear oils of a few decades ago had lead additives that were effective at wear reduction, but not very good for the environment. A long time ago they began to be replaced by gear oils with a phosphorous additive (in itself a decent anti-wear additive) with active sulfur to grip hold of the gears and create a very solid sacrificial layer of material that could be worn off, thereby protecting the gear surface. Eventually it was discovered that the active sulfur was causing corrosion of brass and other soft metals used in differentials and transmissions.

Somewhere around 25 years ago a deactivated or buffered sulfur was developed that would react with the phosphorous to create the protective/sacrificial layer in the conditions created in the gear boxes (temperature and pressure) without being corrosive to the brass, copper, etc. This additive system is used in most gear oils today.

Fwiw, back in the mid-1980's, ex-BSA man Martin Russell (Rustler Racing) rebuilt one of my T160 engines. He advised me to use Castrol R40 in the gearbox instead of the recommended EP90, which I did for many years. Later, triple specialist Phil Pick (Triple Cycles, Waking The Sleeping Beast author) advised Red Line Lightweight Shockproof Synthetic Gear Oil, which I swapped to; over the years, others have posted they also used Superlight or Heavy, seemingly with little difference in feel?

Hth.

Regards,

 

[Hermit47]

Hi Stuart,

ZDDP? That's the stuff.

"... I was advised that there are several other chemical compounds that provide similar or better specialist lubrication than ZDDP and, if at least some of the other compounds are used, the oil can gain a later SAE rating, which can have other benefits over SG."

Quite possibly, but a lot harder to nail down. I'll stick with zinc (ZDDP) rating.

Concerning gear oils:

"This isn't what https://www.widman.biz/uploads/Transaxle_oil.pdf says?"

Thanks for that really interesting read. And I've made note of Widman's list of recommended gear oils as well as yours.

What Widman says about the sulphur's "sacrificial coating" is true, but that coating also reduces friction:

"Sulfur is used in many EP oils and metal-working fluids as an EP additive. The basic way this works is for the sulfur to react at elevated temperatures, such as those experienced by meshing gears to form a sulfide layer. For example, for steel gears, an iron sulfide layer forms on the gear tooth surface. This ductile layer improves sliding contact, preventing scuffing or galling."
(https://www.machinerylubrication.com/Read/28548/sulfur-used-in-lubrication)

So I think the two ideas are really compatible.

In any case, my take-away is that some gear oils anyway CAN damage our Triumph gearboxes' bronze bushes. GL5 lubes are definitely off my list, why take a chance? I have seen recommendations for certain lower viscosity motor oils to be used in gearboxes. I always figure that it must be ok for someone who knows what they're doing, but that lets me out and I find the idea kind of scary.

So I'm still left with the difficulty of finding GL4 products in the area where I live. I look everywhere I go and I only see GL4/GL5. And when I ask at automotive parts outlets I'm told that's all they can get. Same for every big box store here - GL4/GL5 rules! I kind of hate having oil shipped through the mail - the Red Line I ordered last spring had leaked by the time it reached me. But that's my only choice for now.

Without the pressure and temperature found in gearboxes my gear oil experiment is not likely to demonstrate much, but it was interesting to watch the changes in the oils over time. The Lucas started out lighter in color but soon became very cloudy. The Valvolene remained clear, but has darkened considerably. The Lucas product has turned very dark and opaque. Next time I go over to the bike shop I think I'll fish out some of the bronze bushes and see what they look like.

Cheers!

 

[Rusty1]

Thanks for the help again everybody. I've ordered these two from classic oils, they're only 30 miles from me.

https://www.classic-oils.net/Morris-Golden-Film-20W-50

https://www.classic-oils.net/Millers-EP-Gear-Oil-80W90

 

[Shippy]

As you're in the UK another oil you might consider is Duckhams 20W-50 which is back on the market again! You buy it direct. http://duckhams.com
It is slightly different from the original:

It is now a medium detergent oil.
It still has ZDDP.
It is still the classic green colour though!

They suggest it is suitable for older engines that have had an oil filter added.

I have a '72 Daytona 500 with an oil filter in the return line and have used it for two oil changes so far. Very Happy with it! I do regular "oil spot on paper" tests and it performs well. At the "normal" 1500 mile oil change period, when tested there is barely any contamination. No doubt, the filter helps a lot.

Before deciding on Duckhams, I also looked at other classic oils available and downloaded their data sheets a while back.

Others considered:

Castrol Classic - decided against it is not suitable with wet clutches.
Morris's - Having an oil filter I wanted a detergent oil.
Halfords Classic - Seemed more geared towards older classic cars.
Commer Classic (who incidentally appear to make the Halfords Classic) slight differences from Halfords oil, but also seemed aimed primarily at the classic and vintage car market.

These are only my personal views and others may have different priorities and should choose accordingly.

 

[Truckedup]

Take notice the oils above in the list no actually mention ZDDP levels except for one that's quite low at .07-.08...If the oil manufacturer does not list the additive package , you might think it's not anything special?
I lack the knowledge to debate ZDDP levels for a vintage Triumph other than to say it's generally considered that 1200PPM is considered the minimum for a high performance OHV V8 engine with flat tappets like a Chevy...How does the Triumph tappet/cam situation compare to a flat tappet car engine? When these turds were new what was the additive packages of the oil used back then? What oil was recommended by the Triumph factory? Anyone have any accurate oil analysis of those oils used in 1970?
So.............I use oil with at least 1200ppm ZDDP just to be sure...

 

[Shippy]

One of the reasons I selected the Duckhams oil was that they were the only manufacturer prepared to make a statement about ZDDP. This is what they say:

“Modern oils” have approximately one-third of the amount of ZDDP (zinc dialkyl dithiophosphate) required by classic engines which is why Duckhams Classic Q should be used. Studies have also shown that too much ZDDP, often touted as a marketing benefit, can cause stiction of components. Duckhams have an optimised level of ZDDP well above that found in modern engine oils whilst avoiding an unnecessarily high level that can cause component stickiness.

Everybody must make their own choices, but that is good enough for me.

What is a bigger issue for me, that I have got out of this thread, is that of Gear Oil comparability with Yellow Metals. This is something new to me. I've just messaged Castrol's technical support to check up on the Castrol Universal 75W/90 that I have in my gearbox.

 

[Shippy]

There can't be much happening today (31 Dec), I've already had a response (1 hour) from there technical dept about Castrol Universal 75W/90 gear oil and Yellow Metal comparability:

"The Universal is the one I normally suggest, that or the Syntrans Multivehicle 75W-90 ( as long as it doesn’t have a wet clutch ) as both are classed as Mild EP. Most EP gear oils these days though are not an issue as we have moved away from a lot of the aggressive active sulphur EP additives. My normal suggestion is stay away from anything specifically GL-5 rated just in case. The Universal is a GL-4 that will cover a GL-5 due to a special additive package

Another option would be the 10W-40 motorcycle oil - this is close to a 90 grade gear oil in terms of viscosity - but is designed for motorcycle gearboxes and wet clutches also"

So no panic, I can leave the oil in the gearbox.

 

[duc96cr]

Harley Davidson, I believe, can supply transmission oil formulated for older motorcycle transmissions. Also , there are quite a few companies making transmission oil suitable for old Harley’s that might have the right additives.

 

[GoingCommando]

I think this oil test would be applicable for any air-cooled British Twin:


https://www.accessnorton.com/Oil-Tests/NortonOil.php