Gear oil question ?

steviewonder7 · Post by **steviewonder7** » 22 Jun 2006, 18:09

Hi Folks,

A have a question which is above my understanding at the moment and I hope you more knowledgeable folk can help me,although not specific to citroen cars but cars in general.

I'm in the process of changing the clutch on another car which needed the gear oil removing(needed to remove drive shafts).I need to obviously renew the gearbox oil and the manual I have with the car says it needs to be renewed with an API grade SG engine oil viscosity 10W-30 or 10W-40.

I have in my possession Castrol manual EP 80W oil API GL4 MIL-L- 2105
and a bottle of EPEX Hypoid gear Oil 80/90 API GL5 MIL-L-2105.

My question is ,is it o.k to use and mix the two gear oil's mentioned above or should I be use an alternative oil ?

thanks to any replys in advance

Steve

(Ps the car in question is a 1995 Honda accord 2.0 ils 5 speed manual)

AndersDK · Post by **AndersDK** » 22 Jun 2006, 19:32

Well -

I'd instantly think the manual is at fault - a misprint or mis-editing.
API grade SG engine oil viscosity 10W-30 or 10W-40 is a standard mineral/semisynthetic ENGINE oil - used in almost any car found on the roads these days.

An ENGINE oil is NOT suited as a gearbox oil - in odd cases it may even cause damage to the gearbox.

Castrol manual EP 80W oil API GL4 MIL-L- 2105 and EPEX Hypoid gear Oil 80/90 API GL5 MIL-L-2105 are both quality brands manual gearbox oils - definately NOT suited as engine oil.
The difference between these 2 oils is the API spec, where GL5 is a higher grade than GL4. Also I believe the single viscosity 80W oil has a bit more limited viscosity range.
But these 2 oils may be mixed as an add-upp for each other - with no other cosequence that the better oil will be somewhat degrade - or the lower spec oil will be somewhat upgraded - when the 2 are mixed.

I have one important question you must answer befrore you get a go on these oils

Is this Honda engine a specialty compared to the usual 1.8-2.0L PSA engines we widely know off around here ?
I mean : does this Honda engine have the gearbox located as oil sump - like the earlier BLMC cars - i.e. is the engine & gearbox oil shared ?

Kowalski · Post by **Kowalski** » 22 Jun 2006, 23:48

You have to be careful about putting API GL5 gear oils in boxes designed for API GL4, I've heard that there is a problem with the GL5 and brass found in earlier gearboxes. Its better to be safe than sorry....

AndersDK · Post by **AndersDK** » 23 Jun 2006, 00:36

Kowalski wrote:You have to be careful about putting API GL5 gear oils in boxes designed for API GL4, I've heard that there is a problem with the GL5 and brass found in earlier gearboxes. Its better to be safe than sorry....

I agree 100% Kowalski -

Though I cant believe a '95 built Honda would be damaged by a GL5 spec BV oil.
We have to go back into the '80-es to find cars not suitable for GL5 BV oils.

steviewonder7 · Post by **steviewonder7** » 23 Jun 2006, 08:34

Hi Folks,

Thanks for your answers to my querries.I also thought that the manual had a misprint as like you I was suprised to see that it mentioned Engine oil rather than a specific gear oil.

To answer your question Anders,The gearbox and engine definitely do not share lubrication.The engine like many cars has its own wet sump and there's definitely no connection to the gearbox to share lubrication.

I shall play safe and wont mix the two different oils as I dont want to have to remove the gearbox again in the future because of premature failure or degradation of a gearbox component because of my incompetence.

If you believe that a GL4 spec oil is safer to use on this age of gearbox then I shall probably opt to use that in this gearbox.

Just one other question, (I know I could eventually find this somewhere on the net)but what does the MIL-L- 2105 signify as both of the mentioned oils specify this on their respective labels??

Thanks again Steve

AndersDK · Post by **AndersDK** » 23 Jun 2006, 11:49

The MIL-L-2105 simply states a set of minimum requirements for that type of oil - i.e. in this case a hypoid/gear oil.

MIL standards are nothing but documents with numbers. In these documents you have a set of rules/specifications/norms for the material involved to comply - at the time the MIL standard was born. The standard does not in any case validate properties/qualities of the material. Rather it sets a reference for the material.

NOTE : You may have loads of different MIL standards for the same type/family of material. This means that any material complying to a more "stringent" MIL standard may also comply to a less "stringent" MIL standard.
In this example the 2 types of BV oil you stock both complies to the mentioned MIL standard - which simply means that the "lower" spec BV oil is satisfactory to comply with that standard or set of specifications.

You may then understand a certain pattern here :
Mil standards has nothing to do with the popular term "quality"

As an example :
Steel bolts have a limited range of use. This is described in an industri standard - as well as in a similar MIL standard. These specs are referred to like the wellknown 8.8 label on the bolt heads. Nothing to do with quality - but simply which spec's these bolts complies with.

Back to your Honda :
If your Honda manual states that the BV oil must comply with MIL-L-2105 - or vice-versa : an oil complying with this standard - is suitable as BV oil in your Honda - THEN both the GL4 and GL5 spec will also comply - as both oil types complies with the same MIL standard.

You get the idea :
A MIL standard (or industry standard) simply sets a reference point for materials. This reference point can then be used by manufacturers of the material - and the consumers of the material - as both parties then knows exactly what each other is referring to

8) :

Note : BV oil = "boite vitesse" oil = "box of speed" oil = gearbox oil

Kowalski · Post by **Kowalski** » 23 Jun 2006, 12:22

Just to add to what Anders has said, MIL-L-2105 is a US Military specification, its not really relavent to a modern car and you can ignore it.

steviewonder7 · Post by **steviewonder7** » 23 Jun 2006, 14:39

Thanks Anders and Kowalski for your thoughts,very informative.

Luckily enough,this morning at my local shops I came across an owner of another honda accord owner ,the car,albeit a year younger was the same as the one I'm dealing with.Got talking to this chap who happened to have an owners manual for his car in the glove box,henceforth let me have a browse of it for a couple minutes(kind Chap eh?).The book had a minor reference to the transmission oil which stated:-Only use an API service SF or SG grade motor oil with viscosity of 10W-30 or 10W-40.Oil should be drained and refilled with new oil every 36 months or 36k miles whichever comes first.
This was something the owner of the said owners manual hadn't realised and had never done since he owned the car and didnt know if it had been done when he had the car serviced.He was going to check up on how important it was as the car had covered over 161k miles on what he thinks was probably the original gearbox oil.
I must admit i thought that when most cars came off the production line that unless there was a reason for renewing the gearbox oil(eg.removing drive shafts) then the oil needn't be changed,it was there for the life of the gearbox

Thanks again Steve

jeremy · Post by **jeremy** » 23 Jun 2006, 15:23

I seem to remember many years ago reading that Vauxhall deleted the requirement to change back axle oil (and the drain plug?) as the found statistically that changing it caused more problems. The reason for more problems - people forgot to re-fill!

bencowell · Post by **bencowell** » 23 Jun 2006, 18:40

steviewonder7 wrote:The book had a minor reference to the transmission oil which stated:-Only use an API service SF or SG grade motor oil with viscosity of 10W-30 or 10W-40.Oil should be drained and refilled with new oil every 36 months or 36k miles whichever comes first.

That sounds like engine oil not transmission oil which has viscosities around 70 to 90!!!!

406 V6 · Post by **406 V6** » 23 Jun 2006, 19:37

If the manual states engine oil, i would go for it; as some engines are designed to use SAE30, other only use 0W50, for instance.
I once was advised by a competent Vaux chief mechanic that if i changed the g/b oil on the Frontera to a 10W40, both oil and g/b longevity would increase.
If both manual state engine oil, go for it. Whoknows if standar SAE80 will ruin it?

AndersDK · Post by **AndersDK** » 23 Jun 2006, 19:52

406 V6 wrote:... Who knows if standard SAE80 will ruin it?

I know -
It will NOT - whatsoever

Gearoils are designed and specified for extreme mechanical loads (the direct gear contact) which is exactly the situation in any manual gearbox

Engine oil is a compromise - because it has to withstand the high combustion temperatures - at the same time providing the lowest friction as possible.

Its simply 2 different oil types - each designed to their specific purpose. Nothing to do with quality - but purely properties.

That said - I would certainly want to dig deeper into this issue - as I'm defo 100% sure Honda knows thier metiér and specifies correctly for their own products. I would certainly give your local Honda dealer a call - and/or your local oil distributor.

JohnM52 · Post by **JohnM52** » 23 Jun 2006, 23:15

HI all,

A quick check on the valvoline website

http://lubricantadvisor.valvolineeurope.com/select.asp

does indeed confirm engine oil for this gearbox. Check it for yourself.

AndersDK · Post by **AndersDK** » 23 Jun 2006, 23:35

JohnM52 wrote:HI all,

A quick check on the valvoline website

http://lubricantadvisor.valvolineeurope.com/select.asp

does indeed confirm engine oil for this gearbox. Check it for yourself.

Thanks John -

That settles it then - however strange it may seem.
Steve - go buy some 10W-40 engine oil complying to (or is better than) the spec in the Honda manual.
I hereby forbid you to use the BV oil in the Honda Gearbox

DaveW · Post by **DaveW** » 24 Jun 2006, 11:42

It's not entirely unusual for cars with separate gearboxes to use engine oil in the box/diff.
The manufacturers specification for early Peugeot 309's (prior to the MA and BE1 gearboxes - '88) was 15W/40 engine oil.

Dave.