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SAE 80 Oil


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I have been trying to get some SAE 80 oil. I asked for it at a local shop and was given EP80. In Halfords the EP 80 was marked on the back as a substitute for SAE 80.

 

Now i might be being stupid, but although SAE and EP 80 are basically the same, i thought that EP 80 was acidic and would react badly to the bronze and hence i should use SAE80. Could someone please enlighten me?

 

Many thanks

 

Tim (too)

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I have been trying to get some SAE 80 oil. I asked for it at a local shop and was given EP80. In Halfords the EP 80 was marked on the back as a substitute for SAE 80.

 

Now i might be being stupid, but although SAE and EP 80 are basically the same, i thought that EP 80 was acidic and would react badly to the bronze and hence i should use SAE80. Could someone please enlighten me?

 

 

Tim,

 

Not seen any SAE80 straight gear oil, but Morris Lubricants do a Straight 90, called AG90, without those nasty additives that eat yellow metals.

 

Richard

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CP lubricants in southampton should be able to help, i have used them for a while and they have always been really good. usually if they dont have what you need on the shelf the guy will blend it for you or get it in within a day or so.

 

i had a similar problem with SAE50 for the Indian, they had a 25 litre drum on the shelf for £40, sweet :-D

 

http://www.cplubricants.co.uk/classic.htm

 

Baz

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Thanks guys, thats a great help.

 

Now the manual suggests an SAE 80 oil. Which one of the following would be the closest choice?

 

Castrol ST90

Monograde SAE90 gear oil for gearboxes and differentials where a non EP gear oil is specified

 

Castrol SAF-XJ

Fully synthetic SAE 75W-140 hypoid gear oil, formulated for use in both conventional and limited slip differentials

 

Castrol TAF-X

Fully synthetic SAE 75W-90 multi-grade transaxle oil. Designed to help improve cold weather gear selection and keep transmission noise levels to a minimum at high operating temperatures.

Recommended where an API GL4 lubricant is specified

 

Many thanks

 

Tim (too)

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Here's a bit more on oils from Richard Notton...

 

Maybe a bit of background might help.

 

SAE oil ratings only refer to viscosity, other codes tell you what it actually can do.

 

Most misunderstood is the fact that the SAE viscosity ratings _overlap_ and it is essential to realise that "crankcase oil" and "gear oil" have different scales. In fact SAE30 engine oil has the same viscosity as SAE80 gear oil; there are so many scales that the industry now uses centi-Stokes (cSt) as you'll find when speaking to any oil lab tech.

 

It seems common that 50s/60s British mil stuff uses SAE30 engine lube in gearboxes, it could be for commonality and field servicing or because of phosphor bronze bearings that are eroded by the EP or Hypoid additives that gear oils are laced with and give them that recognisable, acrid, cat's P smell. :-)

 

Multigrade oils are loaded with plastic magic; long chain polymers, to hold the viscosity with temperature. All the major makers labs I spoke with seriously warned against multigrades in gearboxes as the plastic will not survive the mechanical forces and will be rapidly reduced to their base stock - a 15W/40 will become just SAE15 quite quickly.

 

It is likely an EP oil in a Ferret or similar Wilson pre-selector box will allow the brake bands to slip too; some automotve makers do rate some mil qualified SAE30 engine oils as a transmission fluid, Caterpillar and Allison to name two.

 

Its not so old hat as you might think, industrial plant from small to gigantic uses 30 in many applications and a detailed read in many current car handbooks and howling Jap m/cycles shows SAE30 quite acceptable in temperate applications. If you ever come across a Detroit Diesel Allison V53 or V71 engine then only SAE30 is acceptable.

 

The original specs you are interested in would be MIL-O-2104B which is called up under OMD110, this is available as Total Rubia B30 but I do not know if it is supplied in less than 205L drums; fortunately between me and some friends we can use it in a year and a half in these quantities, delivered free too from Total-Butler. (Reminds me I must order some tomorrow!)

 

I have known people with Ferret gearbox troubles entirely due to SAE90EP being inadvertently used. They have found red diesel to be a good and cheap flushing oil (diesel _is_ very thin oil) by running at idle for a few minutes and then allowing a protracted period to drain. Replacement with SAE30 had the box behaving as normal.

 

Your mileage may vary of course. ;-)

 

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Thanks guys, thats a great help.

 

Now the manual suggests an SAE 80 oil. Which one of the following would be the closest choice?

 

Castrol ST90

Monograde SAE90 gear oil for gearboxes and differentials where a non EP gear oil is specified

 

Castrol SAF-XJ

Fully synthetic SAE 75W-140 hypoid gear oil, formulated for use in both conventional and limited slip differentials

 

Castrol TAF-X

Fully synthetic SAE 75W-90 multi-grade transaxle oil. Designed to help improve cold weather gear selection and keep transmission noise levels to a minimum at high operating temperatures.

Recommended where an API GL4 lubricant is specified

 

Many thanks

 

Tim (too)

 

Phone 'em up, you can get straight EP80 but it's not listed. For a big company the web site is a tad S**** but on the phone they do know there onions.
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