Royco or Aeroshell 555 turbine oil

Joined
May 21, 2020
Messages
1
Location
Alabama
Good day,

I didn't see this on the forum anywhere so I thought I would ask. Has anyone here every tried the Royco or Aeroshell oil in their transmission? I know it's used by some at the dragstrip and wondered how it would be in a"normal" transmission.
 
I use the rayco in my supercharger. I've never ran it in a transmission, I run RP synchromax in my manual transmissions
 
The AeroShell and Royco "Triple Nickel" turbine oils are based entirely on POEs and contain anti-oxidant, anti-wear, extreme pressure, anti-corrosion and anti-foam additives. They do not contain some typical transmission additives such as detergents, dispersants, ZDDP, S/P EP additives, or friction modifiers. They are very stable at high very temperatures, but more important for transmissions is viscosity and frictional properties. At only 5.3 cSt @ 100°C, these oils are about 15-30% thinner than most ATFs and much thinner than most typical manual gearbox oils. I have no idea what the frictional properties are like. Keep in mind that with a 100% light POE base oil these oils may attack elastomer seals. If you want to try it I would consider it a risky experiment.
 
I work in the aviation industry and from time to time, I see a younger tech pouring 2380 or 254 into his engine! We had one kid who used waste jet engine oil (still very clean) exclusively in his 2.8L powered GM car. The super thin oil did not result in quiet engine operation. But I don't recall any failures.

It's good to remember that these turbine engine oils are tasked to lubricate some very highly loaded gearboxes. Examples include the Pratt PT-6 and the Pratt Geared turbofan, to the Garret 731 geared engines. All of which use gears to reduce the engine's HP output to drive a prop or fan at a much lower RPM.
 
AeroShell 555 is a high load carrying version of MIL-PRF-23699 and AS5780 spec oils and contains an extreme pressure additive, so it is designed to handle highly loaded gearboxes in helicopters and turboprops. Oils like Eastman 2380 and Mobil 254 do not contain an EP additive, only anti-wear (TCP). I would be wary of running an engine or transmission on these oils. It may take time for the damage to be noticeable, but with no ZDDP, detergents, or dispersants you are not doing an engine any good.
 
Originally Posted by HiCountry
Good day,

I didn't see this on the forum anywhere so I thought I would ask. Has anyone here every tried the Royco or Aeroshell oil in their transmission? I know it's used by some at the dragstrip and wondered how it would be in a"normal" transmission.


What do you mean by "normal" transmission? Manual or Automatic???

It has been discussed before .

It is not suitable for either transmission type because:

1) it does not the proper friction modification package,
2) it does not have the proper AW content
3) since it is about 99% POE, the tranny seals and gaskets might have a problem with leakage.

My BIL and I go to the dragstrip with his highly modified S-10 but I can report to you those guys that admitted to using pure turbine oil sure do a lot of tranny rebuilding.
 
Last edited:
Originally Posted by MolaKule
HiCountry said:
My BIL and I go to the dragstrip with his highly modified S-10 but I can report to you those guys that admitted to using pure turbine oil sure do a lot of tranny rebuilding.





I assume this is the quest for lower spin loss? Maybe they should try kerosene.....
 
Last edited:
Originally Posted by Tom NJ
AeroShell 555 is a high load carrying version of MIL-PRF-23699 and AS5780 spec oils and contains an extreme pressure additive, so it is designed to handle highly loaded gearboxes in helicopters and turboprops. Oils like Eastman 2380 and Mobil 254 do not contain an EP additive, only anti-wear (TCP). I would be wary of running an engine or transmission on these oils. It may take time for the damage to be noticeable, but with no ZDDP, detergents, or dispersants you are not doing an engine any good.


Thanks, that's great information. We are now required to use a specific lubricant in our heli gearboxes called Castrol "Transmax". I don't know anything about it, other than it's $2300 initial cost. It came in nondescript grey bottles with no mil spec. (not the automotive stuff) I'd guess it contains the EP additives, as the gear wear patterns are one of the things they were trying to address.

The Pratt PT-6 often comes from the factory, serviced with 2380. They don't seem to experience any gearbox related failures, even over decades of 2380 use (on our PC-12's) . Our Helicopter engines, Troublemeca Arrius 2B1's have internal gearboxes that reduce the free turbine's 56,000 RPM to 6000 RPM. We use 254, not for gearbox protection, but to help reduce coking. In over 20 years of operating these engines, the gearbox is the least of the worries with these junkers, er engines ....
smile.gif
smile.gif
smile.gif
(3 catastrophic engine failures within 1000 hours)
 
Last edited:
From what I can see online, Castrol Transmax is just a line of synthetic ATF and manual transmission oils and sell at Walmart for about $20/gallon. Apparently yours is a special version designed for helicopter gearboxes.

Eastman 2380 is a bit different than all other 23699/AS5780 oils. Like Mobil Jet II it is an old (1964) 2nd generation jet turbine oil, but unlike the other turbine oils all based on PE type POEs, Eastman 2380 is based on a dumbbell blend of TMP and DiPE POEs. The high dose of DiPE type POE and longer fatty acids on the TMP gives it an advantage with respect to lubricity, however it is a negative for deposits at very high temperatures (not an issue in gearboxes).

Mobil Jet 254 is a 3rd generation oil (1979) designed to reduce high temperature coking through the use of a special anti-oxidant. The current 4th generation low coking benchmark oil is Eastman 2197 which uses a special anti-oxidant combined with a low coking POE (for which I have a patent). ExxonMobil and Shell also have 4th generation oils going through approvals, Mobil Jet 387 and AeroShell Ascender respectively.
 
Back
Top