What gear oil to use?

[jjad]

Hello,

I am thinking of changing the gearbox/transmission oil on a R4 GTL. I don't have a handbook, but the GTL Haynes manual suggests using "SAE 80 or SAE 75".

Does anyone know if it should be API GL4 or API GL5? What do these refer to?

Should it be synthetic/mineral or a mixture?

I notice that angel says that the oil must be suitable for hypoid gears.

What type of gear oil do you suggest? Any recommendations gratefully received!

Thanks alot

:smile:

 

[timinder]

I'm not sure if this applies to Gear oils, but most synthetic engine oils contain detergent that if used in a engine that has run on mineral oil can tend to dislodge sludge and other general nastiness that then travels around the engine and can block oilways etc.

I would stick to a mineral oil - every motor factors and most petrol staions these days will sell special gear oil, which will be suitable for hypoid gears.

hope that helps!

 

[angel]

75,80 etc refers to the oil viscosity. You can use a single grade 80 gear oil or better a 75W-80. GL4 or GL5 is a grade given to lubricant oils by API (American Petroleum Institute). It has to do with their physical properties such as resistance to pressures,oxidation,foaming etc. GL4 is adequate for a R4 gearbox,make sure it is suitable for hypoid gears as such gear type is the crownwheel/pinion on the R4 gearbox. Synthetic gear oil is a waste of money on a R4 in my opinion,although it does not harm the gearbox. However, do not mix synthetic with mineral gear oil and do not use any "magic" additives too.

 

[jjad]

Thanks

Thanks for your help!:smile:

 

[godlike]

As I'm posting the last two weak on the forum, I'm doing a maintenance work on my R4.
I'm doing it for the first time so I have a lot of questions, some of them are stupid, but when you do a thing for the first you need to be 100% sure what are you doing.

So I did a change of oil, oil filter, petrol filter, air filter. My next step will be the gearbox oil, because as I remember it's still the first after 18 years.

So I found in the book I should use an SAE 80W oil API GL5 or MIL L2105 B or C.


Thats for the facts, I wonder now it an oil as for example: ELF TRANSELF TYPE B 80W90. Specification API GL-5, MIL-L-2105 D is suitable. I din't found nothing about hypoid gears.

 

[godlike]

Found this on wikipedia:

API GL-5, oils for severe conditions. They contain up to 6.5% effective antiscuffing additives. The general application of oils in this class are for hypoid gears having significant displacement of axes. They are recommended as universal oils to all other units of mechanical transmission (except gearboxes). Oils in this class, which have special approval of vehicle manufacturers, can be used in synchronized manual gearboxes only. API GL-5 oils can be used in limited slip differentials if they correspond to the requirements of specification MIL-L-2105D or ZF TE-ML-05. In this case the designation of class will be another, for example API GL-5+ or API GL-5 LS.

So all API GL-5 are for hypoid gears.

And I continued my search and found:
MIL-L-2105 means the type and B or C the last one ist D is the revision.


Hope this is helpful too somebody.

 

[godlike]

For untiring and fueling the oil should I remove the metal plate or just make my way around?

 

[jjad]

I'm not sure what you mean about the metal plate.

To change the gearbox oil you need to undo the filler plug (I suggest removing this first to make sure that you can refill the gearbox after draining it) and the drain plug. For details of where they are, see this thread. See also this thread.

PS: I found this thread by using the Search box near the top of this page - often the answers are already somewhere else on the forum.

Good luck

 

[godlike]

Yes I know the search box exist, with this method I found this thread end the others on this topic, but I thought this one was the best.

I have a metal plate screw'n down there it just and by the drain plug. I didn't have time today to do a picture, will do I tomorrow or the day after.

 

[godlike]

Here you go, here are the picture. It took me a while, but here they are.

On one you can see the filler plug snapped from above and there's a plate underneath, so you can't see the ground.

Second is made from front, directly in the plate.

And the last is mad from the back side, so you can see the oil drain plug and how far this plate goes back. It end near the drain plug for the gearbox.

 

[jjad]

Thanks for posting the photos - I now know what you meant about the metal plate - I should have realised, sorryops:

I would remove the metal plate - it comes off very easily on our GTL.

Good luck!

 

[godlike]

No need to apologize, I can speak/write english quite good, but when it comes to technical stuff I'm stuck.

Tnx for the help. I'm going remove it, when I do the oil change.

 

[godlike]

I'm going to finally change the oil this weak. One final question , yes another one, hehe.
Are on the filler and drain plug the same washers meant to be placed as thay are on the drain plug for the engine oil.

Asking this before I start changing, because after I drain the oil and eventually see the plug, then it's to late to drive in the same car to a car parts shop.

 

[kevinandkate]

There are no washers on either plug so no problems.

 

[godlike]

Yeah, today I changed the gear oil, finally.

Next stop disc brake pads.

 

[Tine Albreht]

Hi, I still don't know which GL I have to use in my R4 GTL gearbox. GL4 or GL5? It is true that in in the book I says to use an SAE 80W oil API GL5 or MIL L2105 B or C (1987). But is GL5 the same at 2017 as is was at 1987?.
GL5 is much more aggressive for brush/metal elements. I will use 75W80 or 80W90, but does anybody know about GL? If I not get any info, I will use GL4.

 

[petak]

I have put ELF PRESTIGRADE TYPE B 75W80 inside my gearbox and it sais it is GL4+ oil