Need recommendation - 30 weight non-detergent motor oil

1. Didn't realize that I needed to specify the end use of the oil. Sorry! Wasn't trying to be mysterious.
2. It is going in a Laycock de Normanville overdrive unit on a 1966 Triumph TR4A. There were already threads discussing this application - didn't want to start a new discussion, just get an oil recommendation.
3. In those other discussions, oil recommendations are all over the board since the OD shares its oil with the transmissionmission, so whatever goes in the transmission will also go in the OD. This introduces a problem as the transmission calls for 90 weight.
4. In the original manual for the overdrive, Laycock specifies 30 ND oil. I have consulted with the main supplier/restorer of Laycock ODs in England, and they say, even though the 30 weight spec was written 70 years ago, it is still the best oil for the application, notwithstanding all the advancements in lubrication technology. They further say that a 30 weight ND oil will work just fine in the transmission. Based on their recommendation, I'm going to try it in my car.
5. So, I didn't want to get into all this, just needed to find a good source for the oil.
 
Looking for a 30 weight non-detergent motor oil with no antifriction additives - just plain oil.

Recommendations?
The HD appears to mean additives. The 2 different 30hd oils I have are SM and SP rated. SM and SP definitely have detergent in them. Needs to be SA rated, 30sae appears to often be SA rated.
I only put such oil in air compressors.
 
3. In those other discussions, oil recommendations are all over the board since the OD shares its oil with the transmissionmission, so whatever goes in the transmission will also go in the OD. This introduces a problem as the transmission calls for 90 weight.
4. In the original manual for the overdrive, Laycock specifies 30 ND oil. I have consulted with the main supplier/restorer of Laycock ODs in England, and they say, even though the 30 weight spec was written 70 years ago, it is still the best oil for the application, notwithstanding all the advancements in lubrication technology. They further say that a 30 weight ND oil will work just fine in the transmission. Based on their recommendation, I'm going to try it in my car.
Amazon is a good source. A quick search turned up Miller's Oil, which has the proper SAE 90 for your car or your choice of SAE 30, 40, or 50 ND oils. SAE 40 overlaps the lower end of SAE 90 gear oil and SAE 50 overlaps the upper end of SAE 90 gear oil.
Miller's on Amazon

There are many options for SAE 30 ND. Some ND oils are API SA and some are SB. I would opt for a SB rated oil as they have just a bit of anti-wear and a bit of anti-oxidant without any detergent, friction modifiers, or EP additives. Valvoline is a great choice(Amazon, NAPA, Advanced Auto, etc.).

Ed
 
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Sorry, guess I shold have included the application from the start.

The oil is going in the transmission/overdrive of a 1966 Triumph TR4A with the Laycock de Normanville OD. The transmission and OD share the same oil supply. There is a controvercy as to what oil to use as Triumph specifies 90 weight and Laycock specifies 30 weight. The OD relies on a wet clutch for operation, so Laycock wants a non-detergent with no antifriction modifiers - otherwise the clutch is prone to slip. In online Brit car forums, there is much debate. Some say use 90 weight even though that is too heavy for the OD. Others swear by the 30 weight even though it may be too light for the transmission.

So, I consulted with the main British supplier/restorer of Laycock parts and ODs, and they say the 30 weight is what they would use even though the spec was wwritten 70 years ago - it is still best for this application in their opinion. Plus, they say it will work fine in the transmission as well.

Based on this, I have decided to try the 30 weight. If I don't like it, easy enough to drain and switch to 90.

Having already made the decision, I didn't want to open the 90 vs 30 debate again, just wanted to find a good source for an excellent 30 weight ND oil with as few antifriction modifiers as possible.

Hope this clarifies the situation, and once again, my apologies for not having included all this initially.

Thanks for your suggestions!

Ted
 
Thanks for the link! Looking at it, I see the same old debate- gear oil vs engine oil vs ? I started this thread because I haad already made up my mind and just wanted the best source for the 30 weight ND oil. The link makes excellent reading, though, so I reallly do appreciate it - hadn't seen it before
Just some general info for you that seems would be helpful for you...

Gear oil and engine oil are rated on two different scales. SAE 40 and SAE 50 weight motor oil overlap the viscosity range of 90 weight gear oil so those 30 and 90 weight specs are not that far apart. I've linked to a chart from the Amsoil site that shows how they match up.

What I would suggest is you go get a 10w-40 or 20w-50 JASO MA2 rated 4t motorcycle oil specifically designed for wet clutches. These will have much better wear protection than a junky non-detergent 30 weight and are specifically engineered modern oils that will do exactly what you're looking for. Motul, Valvoline, Castrol, etc all make products that will be way better. Triumph sells a 10w-50 4t oil that would be great, too.


Comparative_Viscosity_Chart_550wide.jpg
 
Hm,frankly I'd want to use something of GL-3 or GL-4 level with 1a--1b copper corrosion rating,mineral . Something of this kind:
https://penngrade1.com/wp-content/u...lti-Purpose-GL-4-SAE-80W-90-Gear-Oil-2019.pdf
Viscosity-wise, at oper. temperatures it behaves like SAE 40.
There are other MTF's of 75w-90 or 75w-80 viscosity,but are synthetic.
Also have in mind that SAE 90 from back then is not the 90 today (the min.-max. viscosity span was much wider).

Also,I would look further into what Caterpillar TO-4 fluids of 30 and 40 grade offer :
https://www.petersoncat.com/sites/cat/files/downloads/Cat TDTO.pdf
https://www.petersoncat.com/sites/cat/files/downloads/Cat TDTO SYN.pdf
https://www.sinclairoil.com/sites/default/files/SL TO-4 FLUID.pdf
Yellow metal safe,wet clutches compatible,anti-foaming req. etc.

Seems like ATF Type F was FF in late Volvo Laycock OD transmissions (owner's manuals recommend F or G type) .
"Motor oil, gear oil, ATF were all specified and used in Laycock de Normanville OD units by different automobile manufactures. Through the years that Volvo put OD gearboxes in their cars they specified all three...BMC specified motor oil for use in the MGB's OD gear box and Triumph spec'd gear oil. Use whichever oil you want."
https://www.triumphexp.com/forum/sp...fluid-fill-transmission-and-d-type-od.857178/

This however needs furher investigations about the gen.differencies of the transmission and the use of lower visc.fluids (ATFs).
If you'd like to stay closest to what the manual recommended, what edhackett proposed above .

Lubriplate have some ND oils too :
https://www.lubriplate.com/getConte.../9_6_Non-Detergent_Motor_Oils.pdf?language=en
...but they're only API SA level.
 
Used whatever the local NAPA had on sale we would buy 12 Qts at one time. Normally it was NAPA house brand wolf's head or some other brand like Cam2 or Mystik
 
The layshaft bearings in the Triumph transmission are a major weak point. While the main shaft bearings are large caged ball type, the laygear is supported by small needle bearings, which commonly fail. And when the bearings fail, they take out the laygear & layshaft, which are expensive parts. I'm not familiar with the workings of the OD unit, but unless there are specific critical lubrication needs requiring a thin oil, I'd be targeting a higher viscosity gear oil, not SAE 30.
 
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The layshaft bearings in the Triumph transmission are a major weak point. While the main shaft bearings are large caged ball type, the layshaft is supported by small needle bearings, which commonly fail. I'm not familiar with the workings of the OD unit, but unless there are specific critical lubrication needs requiring a thin oil, I'd be targeting a higher viscosity gear oil, not SAE 30.
Gear oil over engine oil for sure if protecting needle bearings is a priority. But I'd want a gear oil without friction modifier. That's somewhat hard to find as many off-the-shelf gear oils include it for use with limited slip clutches.
 
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