Replacement for low temp lubricating oil MIL-L-7870

[pagirard]

Hi everyone,

I did my first oil change on the new-to-me 74 M20E with the assistance of the previous owner and wonderful A&P Keith. He showed me the ropes and took the stress out of the oil change. Shout out to Pat who came to the rescue when I realized I ordered the wrong oil filter....

Now to my question, the service manual I could find for the 1960's Mooney have the following recommendations for oils and grease:

And my question is what modern equivalent are you using for the MIL-L-7870 (to be used on the control rods and such) and also the MIL-G-7711 grease.

I did some googling but got lost with the amount of non-aircraft response.

If the question is wrongly formulated, perhaps I may ask what oil and grease are you using for the control rods and the gear grease fittings

 

As usual, thanks in advance for your help, the resources found on this forum like the jig to collect the oil below the filter helped me tremendously !

 

Here is the jig in action:

:

[Rjfanjet]

Triflow or LPS 2 for the heim  joints.

 

 

 

[carusoam]

Did you use Google to search MS?

This is a common question… since the planes are 50+yrs old… and the lubricants have improved over the decades…

In some cases, the modern lubricant isn’t available because of supply chain issues…

Somewhere around here is a list of products for the various things that need lube…

Best regards,

-a- 

[N201MKTurbo]

You can still get it.

https://www.aircraftspruce.com/catalog/eppages/royco363.php

 

You will never go wrong using the proper lubricants. Everybody seems to have their favorite stuff and think it is better than the specified lube.

Edited April 20, 2022 by N201MKTurbo

[N201MKTurbo]

MIL-G-7711 is Aeroshell #6

 

AeroShell Grease 6 Approved to : MIL-PRF-24139A First Approved : April 1965 Type: It is a general purpose grease composed of a mineral oil thickened with Microgel®, possessing good all-round properties within a limited range. It is inhibited against oxidation and corrosion and has good water resistance and low noise capability. Application: AeroShell Grease 6 is a general purpose airframe grease for use in antifriction bearings, gearboxes and plain bearings within the temperature range of –40°C to +121°C. Manufacturing Plant : Shell Canada , Calgary Other approved products: No other products approved to Mil-PRF-24139A ASG 6 was developed in1963 and was approved to the US specification MIL-G-7711A . The MIL-G-7711A specification was cancelled by the US military on 4 March 1971; it was replaced by MIL-G-81322 . Shell then decided to gain approval for ASG 6 against MIL-PRF-24139A as it already had developed ASG 22. Nyco market a product called GN 15 which they claim in their brochures is approved to MIL-G-7711A. Specifying that “meet the requirements of” or “is equivalent to” a specification, does not necessarily mean it is formally approved under the relevant standard. Comments: Although we have no details of the actual aircraft types in which ASG 6 has been used over these years, we do know that the product has been used in Russian-made aircraft, where the customer specifically ordered grease which was an analogue to CIATIM-201, CIATIM-202, CIATIM-203 or OKB-122-7 but they now may be using ASG 22 which also an analogue of the same Russian specifications.

Edited April 20, 2022 by N201MKTurbo

[PT20J]

You can look up MIL specs here (useful to find out latest version especially when a specification has been superseded): http://everyspec.com

You can find approved vendors and their commercial product part numbers here: https://qpldocs.dla.mil

Skip

[pagirard]

5 hours ago, N201MKTurbo said:

You can still get it.

https://www.aircraftspruce.com/catalog/eppages/royco363.php

 

You will never go wrong using the proper lubricants. Everybody seems to have their favorite stuff and think it is better than the specified lube.

I saw that product but wasn't sure if MIL-PRF-7870 was the same as MIL-L-7870. I need to read the documents here to understand the nomenclature - thanks for your help

[pagirard]

5 hours ago, N201MKTurbo said:

MIL-G-7711 is Aeroshell #6

 

AeroShell Grease 6 Approved to : MIL-PRF-24139A First Approved : April 1965 Type: It is a general purpose grease composed of a mineral oil thickened with Microgel®, possessing good all-round properties within a limited range. It is inhibited against oxidation and corrosion and has good water resistance and low noise capability. Application: AeroShell Grease 6 is a general purpose airframe grease for use in antifriction bearings, gearboxes and plain bearings within the temperature range of –40°C to +121°C. Manufacturing Plant : Shell Canada , Calgary Other approved products: No other products approved to Mil-PRF-24139A ASG 6 was developed in1963 and was approved to the US specification MIL-G-7711A . The MIL-G-7711A specification was cancelled by the US military on 4 March 1971; it was replaced by MIL-G-81322 . Shell then decided to gain approval for ASG 6 against MIL-PRF-24139A as it already had developed ASG 22. Nyco market a product called GN 15 which they claim in their brochures is approved to MIL-G-7711A. Specifying that “meet the requirements of” or “is equivalent to” a specification, does not necessarily mean it is formally approved under the relevant standard. Comments: Although we have no details of the actual aircraft types in which ASG 6 has been used over these years, we do know that the product has been used in Russian-made aircraft, where the customer specifically ordered grease which was an analogue to CIATIM-201, CIATIM-202, CIATIM-203 or OKB-122-7 but they now may be using ASG 22 which also an analogue of the same Russian specifications.

This is very helpful - thanks a lot for the detailed explaination

[pagirard]

3 hours ago, PT20J said:

You can look up MIL specs here (useful to find out latest version especially when a specification has been superseded): http://everyspec.com

You can find approved vendors and their commercial product part numbers here: https://qpldocs.dla.mil

Skip

Great resource - thanks a lot for sharing

I didn't expect to read the 3rd generation of a lubricant spec when I asked this question but it's interesting to see that something as simple a a low temperature lubricating oil have seen their spec updated 3 times in the past 24 years :

[Will.iam]

Is lubricating oil a fancy term for grease? Or is it different?

[Fly Boomer]

2 hours ago, Will.iam said:

Is lubricating oil a fancy term for grease?

According to interflon.com "At room temperature, greases are usually solid, while oils are usually liquid."

[PT20J]

3 hours ago, Will.iam said:

Is lubricating oil a fancy term for grease? Or is it different?

Grease is simply oil mixed with a thickener. The oil can be either mineral or synthetic. Thickeners are classified as soap or non-soap. The most common modern grease thickener is Lithium soap. Many older non-soap greases use a mineral clay thickener. Greases with different thickeners and base oils may not be compatible and should not be mixed, so if switching grease (or if the type of grease previously used is unknown) it is best to remove all the old grease before re-greasing. https://www.twinoils.com/news/a-guide-to-grease-thickeners/

Skip

[Guest]

21 hours ago, pagirard said:

Hi everyone,

I did my first oil change on the new-to-me 74 M20E with the assistance of the previous owner and wonderful A&P Keith. He showed me the ropes and took the stress out of the oil change. Shout out to Pat who came to the rescue when I realized I ordered the wrong oil filter....

Now to my question, the service manual I could find for the 1960's Mooney have the following recommendations for oils and grease:

And my question is what modern equivalent are you using for the MIL-L-7870 (to be used on the control rods and such) and also the MIL-G-7711 grease.

I did some googling but got lost with the amount of non-aircraft response.

If the question is wrongly formulated, perhaps I may ask what oil and grease are you using for the control rods and the gear grease fittings

 

As usual, thanks in advance for your help, the resources found on this forum like the jig to collect the oil below the filter helped me tremendously !

 

Here is the jig in action:

:

Mil 7870 is a general purpose lubricating oil for flight control hinge bearings and rod ends according to my Comanche maintenance manual.  It is not an engine lubricating oil.

Clarence

[AIREMATT]

14 hours ago, PT20J said:

Grease is simply oil mixed with a thickener. The oil can be either mineral or synthetic. Thickeners are classified as soap or non-soap. The most common modern grease thickener is Lithium soap. Many older non-soap greases use a mineral clay thickener. Greases with different thickeners and base oils may not be compatible and should not be mixed, so if switching grease (or if the type of grease previously used is unknown) it is best to remove all the old grease before re-greasing. https://www.twinoils.com/news/a-guide-to-grease-thickeners/

You can look up MIL specs here (useful to find out latest version especially when a specification has been superseded): http://everyspec.com

You can find approved vendors and their commercial product part numbers here: https://qpldocs.dla.mil

Skip has all the great reference links!!

Thanks!!

[MB65E]

Here!

https://www.bac-online.com/default.aspx?page=item+detail&itemcode=D-5261NS-12OZ#tab-1

BAC has lots of other nice things too.

5261NS is the best -7870 spray I’ve used. LPS believe it or not doesn’t have the correct mil spec. 
 

-Matt

[CaptainRamius]

Working on my first annual. Reading the comments (I'm not attacking you), some didn't really answer pagirard's specific question and merely provided links to look up or comments. Some like this, some like that. When it comes to aviation (life and death), do we have a choice of what to use?  Part 91, I suppose we can. Seems like everyone has their own preference leaving me as confused as when I started researching. 

Unless you're squeezing grease through a gun into a Zerk fitting (Mobil 28?) or Mobil100 for wheel bearings the rest pretty much has to be a spray can (i.e. not grease). How else to get lubricant into a Heim bearing? Not with a finger. 

I read that Mobil 28 (grease) can be used for MIL-L-7870 (oil). What? How?

What about the Phenolic blocks that guide the aileron push rods through the wing?  Lubriplate?

What about the starter gear (mix kerosene with graphite)!  What ratio?

I was a Jet Engine mechanic then  Flight Engineer (35 years). I've worked on many jets and used to reading "use this for that". This is my first GA airplane.   

May I please ask the audience for specific sprays, specific greases for specific applications, and where you buy them? Beside Aircraft Spruce, I've learned about SkyGeek, QAA.com, & LASAR,  

Blue skies.

[N201MKTurbo]

As I said above, you will not get consensus on which lube to use. You cannot go wrong using what is specified in the maintenance manual. Most people don't BTW.

My theory is that any lube is better than no lube. Almost every Mooney I look at for the first time has many lubrication points that havent been lubed in years.

[EricJ]

1 hour ago, CaptainRamius said:

Working on my first annual. Reading the comments (I'm not attacking you), some didn't really answer pagirard's specific question and merely provided links to look up or comments. Some like this, some like that. When it comes to aviation (life and death), do we have a choice of what to use?  Part 91, I suppose we can. Seems like everyone has their own preference leaving me as confused as when I started researching. 

Unless you're squeezing grease through a gun into a Zerk fitting (Mobil 28?) or Mobil100 for wheel bearings the rest pretty much has to be a spray can (i.e. not grease). How else to get lubricant into a Heim bearing? Not with a finger. 

I read that Mobil 28 (grease) can be used for MIL-L-7870 (oil). What? How?

What about the Phenolic blocks that guide the aileron push rods through the wing?  Lubriplate?

What about the starter gear (mix kerosene with graphite)!  What ratio?

I was a Jet Engine mechanic then  Flight Engineer (35 years). I've worked on many jets and used to reading "use this for that". This is my first GA airplane.   

May I please ask the audience for specific sprays, specific greases for specific applications, and where you buy them? Beside Aircraft Spruce, I've learned about SkyGeek, QAA.com, & LASAR,  

Blue skies.

I just uploaded a file to the Airframe Manuals area called "Mooney lubrication notes.docx" that has a synopsis of the various lubricants indicated in the M20J maintenance manual, as well as current products that are compliant.    I can never remember what to use where, so I made this so that I didn't get any more confused than usual.   There was probably an earlier version that I uploaded previously but it may have gotten lost in one of the various server migrations/purges/respawns.   Once that doc gets approved it should be available.

Edit:   It's not that much text, so I figured I could just copy it here as well.   The Greek letters and symbols used in the manual didn't copy.:

 

Mooney lubrication notes, by eaj, 8/22/2020, updated 4/19/2022.   See M20J SMM Section 5-20-7 P 18-20.

 Order:  Lube items, manual symbol, specification, compliant products.

 Landing Gear Zerks, W, MIL-G-81322, superceded by MIL-PRF-81322.   Mobil Grease 28 or Aeroshell 22

 Rod ends, y, Teflon (PTFE), Tri-Flow specified.

 Bellcranks, u-joints, bungee/spring attachments, flap indicator cable, fuel selector valve, baggage and cabin door hinges, control surface hinges, S, MIL-L-7870, superceded by MIL-PRF-7870C (or latest).  Low-temp general purpose light oil.   Suggested is 3-in-1, LPS 2.

 Stabilizer trim jackscrew/actuator, chain and gear, j, specified Aeroshell 7

 Wheel Bearings, Y, MIL-L-3545, superceded by MIL-PRF-81322G (or latest), Aeroshell 22 or Mobil SHC 100

 Control rod guide blocks, D, MIL-G-23827 or MIL-G-3278, superceded by MIL-PRF-23827,  Aeroshell 7 or Aeroshell 33   (NOTE:  Aeroshell 7 and Aeroshell 33 are not compatible with each other, do not mix.)

 Gear or flap actuator gear box, W, MIL-G-81322 superceded by MIL-PRF-81322,  Aeroshell 22 or Mobil SHC 100

 NOTE:  SBM20-190B for Dukes/ITT gear actuator gearbox indicates Aeroshell 7, or MIL-PRF-23827 with 10% by vol molybdenum disfulfide.   Aeroshell 64 contains molybdenum disulfide and can be used.

 Gear or flap actuator Ball screw, ë, specified Lubriplate 630AA

 Door latches,  , Door Ease Stick Lubricant

Note:  Aeroshell 22 covers most grease requirements, and cannot be mixed with Aeroshell 5
Note:  Aeroshell 7 (trim, guide blocks), and Lubriplate 630AA (ball screws) covers the rest of the grease requirements.  

Note:  Hartzell propeller is Aeroshell 5 (preferred) or 6.  1 oz (6 pumps), stop if comes out the engine side fitting.

 

Torque:

Spark Plug Installation Guidelines

1. Spark plug gap must be set at 0.016 to 0.022 in. (0.40 to 0.60 mm).

2. Always install a spark plug with a new gasket (P/N STD-295).

3. Use a copper-based anti-seize compound or engine oil on spark plug threads starting two full threads from the electrode, but DO NOT use a graphite-based compound.

4. Use installation torque values shown in Table 1.   420 in-lbs, (35 ft-lbs)

 

Injector torque:   60 in-lbs

Magneto torque:  17 ft-lbs, 204 in-lbs, per Lycoming SI-1508C

Gascolator filter:  15-20 in lbs.

 

Sorted by lubricant type for application efficiency:

 

Aeroshell 6:

Note:  Hartzell propeller is Aeroshell 5 (preferred) or 6.  1 oz (6 pumps), stop if comes out the engine side fitting.  Remove cylinder-side fitting, pump into engine-side fitting for each blade.

Aeroshell 7:

Stabilizer trim jackscrew/actuator, chain and gear, j, specified Aeroshell 7

Control rod guide blocks, D, MIL-G-23827 or MIL-G-3278, superceded by MIL-PRF-23827,  Aeroshell 7 or Aeroshell 33   (NOTE:  Aeroshell 7 and Aeroshell 33 are not compatible with each other, do not mix.)

Aeroshell 22:

Landing Gear Zerks, W, MIL-G-81322, superceded by MIL-PRF-81322.   Mobil Grease 28 or Aeroshell 22

Wheel Bearings, Y, MIL-L-3545, superceded by MIL-PRF-81322G (or latest), Aeroshell 22 or Mobil SHC 100

Gear or flap actuator gear box, W, MIL-G-81322 superceded by MIL-PRF-81322,  Aeroshell 22 or Mobil SHC 100

 

Tri-Flow:

Rod ends, y, Teflon (PTFE), Tri-Flow specified.

 

“Light oil”

Bellcranks, u-joints, bungee/spring attachments, flap indicator cable, fuel selector valve, baggage and cabin door hinges, control surface hinges, S, MIL-L-7870, superceded by MIL-PRF-7870C (or latest).  Low-temp general purpose light oil.   Suggested is 3-in-1, LPS 2.

 

Lubriplate:

Gear or flap actuator Ball screw, ë, specified Lubriplate 630AA

 

Door latches,  , Door Ease Stick Lubricant

 

Aeroshell 64 or Aeroshell 7 w/moly:

NOTE:  SBM20-190B for Dukes/ITT gear actuator gearbox indicates Aeroshell 7, or MIL-PRF-23827 with 10% by vol molybdenum disfulfide.   Aeroshell 64 contains molybdenum disulfide and can be used.   Remove bottom bolt when injecting grease in gearbox.

 

[N201MKTurbo]

I have an  A-13A-1 clock in my plane. I cleaned and lubed it a few years ago. It was the most complicated mechanical assembly I have ever taken apart and put back together. It made an aircraft engine seem like child's play. The service manual had a specification for the barrel grease that took a lot of research to figure out what it was and where to get it. After going through about 10 different obsolete specifications and finding out what they were superseded by, it ended up being of all things Aeroshell 6. It still works flawlessly BTW. I could never find the jewel oil that was specified. So I used Moebius watch oil.