Oil for manual gearbox

[eltonjohan]

I'm about changing the oil in my stock 4 speed manual gearbox, but am a bit confused about what oil to choose.
In the manual "SAE 80" oil is recommended but also says that it shouldn't be of hypeoid type. The oil I found so far is a "SAE 80" but is also specified to be used as a hypeoid oil...

I would be happy if anyone has a recommendation of what oil to use!


Regards
Johan

 

[eltonjohan]

I'm about changing the oil in my stock 4 speed manual gearbox, but am a bit confused about what oil to choose.
In the manual "SAE 80" oil is recommended but also says that it shouldn't be of hypeoid type. The oil I found so far is a "SAE 80" but is also specified to be used as a hypeoid oil...

I would be happy if anyone has a recommendation of what oil to use!


Regards
Johan

 

[Percy]

I'm about changing the oil in my stock 4 speed manual gearbox, but am a bit confused about what oil to choose.
In the manual "SAE 80" oil is recommended but also says that it shouldn't be of hypoid type. The oil I found so far is a "SAE 80" but is also specified to be used as a hypoid oil... I would be happy if anyone has a recommendation of what oil to use! Regards Johan

Use Hypoid lube at your own peril on a stock manual transmission. It is not recommended for a reason.

Hypoid additives are incompatible with the phosphor-bronze /brass synchros in your manual transmission. Evidently, the strong sulfur-smelling additives have a corrosive effect on bronze-brass and similarly based metals. Hypoid gear lube is more typically used in hypoid/bevel cut gears found in differentials and manual steering boxes. THe hypoid additives lend the lubricant greater shear strength which is important for bevel cut gears. There were other transmissions that could use hypoid gear oil, but not the manual transmissions BMW used in the 60's and 70's. I think there were Japanese made manual transmissions that also had phosphor bronze synchros too, so you might want to explore where those Datsun owners get their lubricants. Many European makers of the era used the same transmissions, but there may be exceptions.

One indicator is a GL4 on the label (for non-hypoid) rather than GL5 or GL6 (for hypoid). It is available, you just have to look a little harder for it. If you read your manual, you will notice there is an "emergency" alternative: ("Hd engine oil). http://www.cscoupe.org/tech/handbook/at_a_glance.htm Another possibility is automatic transmission fluid. I would not be surprised if you found synthetic gear oil compatible with all transmissions - without potentially corrosive hypoid additives. The synthetic lubricants may not need the hypoid additives because of its superior anti wear properties. Look on the various oil manufacturer's web sites. Just read the labeling carefully, or be very lucky. If all else fails, there is always the dealer.

Good luck

 

[Percy]

I'm about changing the oil in my stock 4 speed manual gearbox, but am a bit confused about what oil to choose.
In the manual "SAE 80" oil is recommended but also says that it shouldn't be of hypoid type. The oil I found so far is a "SAE 80" but is also specified to be used as a hypoid oil... I would be happy if anyone has a recommendation of what oil to use! Regards Johan

Use Hypoid lube at your own peril on a stock manual transmission. It is not recommended for a reason.

Hypoid additives are incompatible with the phosphor-bronze /brass synchros in your manual transmission. Evidently, the strong sulfur-smelling additives have a corrosive effect on bronze-brass and similarly based metals. Hypoid gear lube is more typically used in hypoid/bevel cut gears found in differentials and manual steering boxes. THe hypoid additives lend the lubricant greater shear strength which is important for bevel cut gears. There were other transmissions that could use hypoid gear oil, but not the manual transmissions BMW used in the 60's and 70's. I think there were Japanese made manual transmissions that also had phosphor bronze synchros too, so you might want to explore where those Datsun owners get their lubricants. Many European makers of the era used the same transmissions, but there may be exceptions.

One indicator is a GL4 on the label (for non-hypoid) rather than GL5 or GL6 (for hypoid). It is available, you just have to look a little harder for it. If you read your manual, you will notice there is an "emergency" alternative: ("Hd engine oil). http://www.cscoupe.org/tech/handbook/at_a_glance.htm Another possibility is automatic transmission fluid. I would not be surprised if you found synthetic gear oil compatible with all transmissions - without potentially corrosive hypoid additives. The synthetic lubricants may not need the hypoid additives because of its superior anti wear properties. Look on the various oil manufacturer's web sites. Just read the labeling carefully, or be very lucky. If all else fails, there is always the dealer.

Good luck

 

[bert35csi]

Here in the States, many Bmw enthusiasts use Redline MTL manual transmission oil religiously. Good stuff, have used this oil and nothing else on my Bmw gearboxes for years. Not familiar with any of the European gearbox oil products though.

Bert
72 3.5 CSi
88 M6

 

[bert35csi]

Here in the States, many Bmw enthusiasts use Redline MTL manual transmission oil religiously. Good stuff, have used this oil and nothing else on my Bmw gearboxes for years. Not familiar with any of the European gearbox oil products though.

Bert
72 3.5 CSi
88 M6

 

[eltonjohan]

Great, thanks for the answers - now I know some more about what hypeoid oil means.
I probably choose the Redline gear box oil then.

I found one alternative for the Redline, but it says both API GL-4 and GL-5 on the bottle (synthetic).

 

[eltonjohan]

Great, thanks for the answers - now I know some more about what hypeoid oil means.
I probably choose the Redline gear box oil then.

I found one alternative for the Redline, but it says both API GL-4 and GL-5 on the bottle (synthetic).

 

[DJSimca]

I'm about changing the oil in my stock 4 speed manual gearbox, but am a bit confused about what oil to choose.
In the manual "SAE 80" oil is recommended but also says that it shouldn't be of hypeoid type. The oil I found so far is a "SAE 80" but is also specified to be used as a hypeoid oil...

I would be happy if anyone has a recommendation of what oil to use!


Regards
Johan

I changed to a 5-speed Getrag a couple of years ago and poured Castrol EP 80w on the gearbox. The oil has worked flawlessly but this thread did prompt me to contact my Castrol oil guy to find out the details.

This is what he said ... and by the way you can read about it here (it's in Danish but I am sure you can spell your way through it )
http://www.castrolshop.dk/shop/castrol-ep-80w-273p.html

Castrol EP 80w is a hypoid oil which all GL4, GL5 and GL6 oils are.

The question regarding what oil to use in an old BMW gearbox is not whether the oil is hypoid or not but rather whether it is a GL4 or a GL5 oil.

GL5 oils are indeed more 'aggressive' and can attack bronze, brass and copper as used in old gearboxes - GL4 oils do not attack these metals.

Hope this helps.

 

[DJSimca]

I'm about changing the oil in my stock 4 speed manual gearbox, but am a bit confused about what oil to choose.
In the manual "SAE 80" oil is recommended but also says that it shouldn't be of hypeoid type. The oil I found so far is a "SAE 80" but is also specified to be used as a hypeoid oil...

I would be happy if anyone has a recommendation of what oil to use!


Regards
Johan

I changed to a 5-speed Getrag a couple of years ago and poured Castrol EP 80w on the gearbox. The oil has worked flawlessly but this thread did prompt me to contact my Castrol oil guy to find out the details.

This is what he said ... and by the way you can read about it here (it's in Danish but I am sure you can spell your way through it )
http://www.castrolshop.dk/shop/castrol-ep-80w-273p.html

Castrol EP 80w is a hypoid oil which all GL4, GL5 and GL6 oils are.

The question regarding what oil to use in an old BMW gearbox is not whether the oil is hypoid or not but rather whether it is a GL4 or a GL5 oil.

GL5 oils are indeed more 'aggressive' and can attack bronze, brass and copper as used in old gearboxes - GL4 oils do not attack these metals.

Hope this helps.

 

[Ed G]

Percy is right on, though for other reasons as well. It is the "EP" (Extreme Pressure) additives that have a tendency to make the synchros not grip the way they should. In laymen's terms, the oil is too slippery to afford proper operation. A non EP oil should be used.

 

[Ed G]

Percy is right on, though for other reasons as well. It is the "EP" (Extreme Pressure) additives that have a tendency to make the synchros not grip the way they should. In laymen's terms, the oil is too slippery to afford proper operation. A non EP oil should be used.

 

[eltonjohan]

Once again, thanks a lot for all info.
I just bought Redline MTL (GL-4) and it should hopefully be working fine!

 

[eltonjohan]

Once again, thanks a lot for all info.
I just bought Redline MTL (GL-4) and it should hopefully be working fine!

 

[Percy]

Castrol EP 80w is a hypoid oil which all GL4, GL5 and GL6 oils are.

The question regarding what oil to use in an old BMW gearbox is not whether the oil is hypoid or not but rather whether it is a GL4 or a GL5 oil.

GL5 oils are indeed more 'aggressive' and can attack bronze, brass and copper as used in old gearboxes - GL4 oils do not attack these metals.

The hypoid -nonhypoid is anything but clear.
BMW's manual clearly specifies NO hypoid oil to be used in the transmission. This circa 1970-75 pronouncement should be read contextually since the author/s could not foresee 30+ years in the future. (how about all that high octane unleaded fuel!) If a gear lube is suitable for use with hypoid gears (as might be the case with newer synthetics) that may or may not be read to mean the "oil is hypoid" versus oil suitable for hypoid gears without the corrosive hypoid additives.

A GL4 label is probably a safe bet but that is no guarantee. Confusion might exist because of a perception that some GL5 products meet or exceed the GL4 requirements and are thus suitable for both GL4 and GL5 applications. Use of the terms "Extreme Pressure" adds to the possible confusion as it could refer to both GL4 and GL5 (see below). The safest approach is to carefully read the labeling. For example notice on this site Delvac 50 specifies that it is safe for copper alloys. Yet it also says it may not be suitable for hypoid gears as in differentials. http://www.mobil.com/USA-English/Lu...il_Delvac_Synthetic_Transmission_Fluid_50.asp

There is always the smell test. If it smells like sulfur, it probably is GL5 and not suitable for the 262 Getrag transmissions. And the confusion is hardly limited to the vintage BMW crowd. See for example this thread: http://www.mbfanatics.org/forum/index.php?showtopic=3352 . Some companies address the issue by labeling things as "classic" products: http://www.britishsportscars.nl/Castrol Classic Oils.htm . But this does not fully resolve the issue. Note "EP80/90" "For manual transmissions and some Hypoid differentials." :wink:

 

[Percy]

Castrol EP 80w is a hypoid oil which all GL4, GL5 and GL6 oils are.

The question regarding what oil to use in an old BMW gearbox is not whether the oil is hypoid or not but rather whether it is a GL4 or a GL5 oil.

GL5 oils are indeed more 'aggressive' and can attack bronze, brass and copper as used in old gearboxes - GL4 oils do not attack these metals.

The hypoid -nonhypoid is anything but clear.
BMW's manual clearly specifies NO hypoid oil to be used in the transmission. This circa 1970-75 pronouncement should be read contextually since the author/s could not foresee 30+ years in the future. (how about all that high octane unleaded fuel!) If a gear lube is suitable for use with hypoid gears (as might be the case with newer synthetics) that may or may not be read to mean the "oil is hypoid" versus oil suitable for hypoid gears without the corrosive hypoid additives.

A GL4 label is probably a safe bet but that is no guarantee. Confusion might exist because of a perception that some GL5 products meet or exceed the GL4 requirements and are thus suitable for both GL4 and GL5 applications. Use of the terms "Extreme Pressure" adds to the possible confusion as it could refer to both GL4 and GL5 (see below). The safest approach is to carefully read the labeling. For example notice on this site Delvac 50 specifies that it is safe for copper alloys. Yet it also says it may not be suitable for hypoid gears as in differentials. http://www.mobil.com/USA-English/Lu...il_Delvac_Synthetic_Transmission_Fluid_50.asp

There is always the smell test. If it smells like sulfur, it probably is GL5 and not suitable for the 262 Getrag transmissions. And the confusion is hardly limited to the vintage BMW crowd. See for example this thread: http://www.mbfanatics.org/forum/index.php?showtopic=3352 . Some companies address the issue by labeling things as "classic" products: http://www.britishsportscars.nl/Castrol Classic Oils.htm . But this does not fully resolve the issue. Note "EP80/90" "For manual transmissions and some Hypoid differentials." :wink: