Gearbox oil ... with Hypoid oil added. Allowed or a No - No?!

[james2747]

Not really a Mercedes issue, BUT ....
Was renewing gearbox oil in 'her who has to be obeyed' Nissan Micra.
Needed nearly 3 litres which I thought I had but found I had only 2 litres when I came to re-fill.
I had an unused litre of my Merc rear axle oil, (EP 75w 90 Hypoid semi synthetic) sitting on the garage shelf.
To complete the job without a delay, I therefore added this to the 2 litres of EP80w - 90 gearbox oil I had bought for the Micra.
I am pretty confident this will have no discernible benefit or negative but if any oil experts out there?
Will this 'mix' better protect the gearbox.
Will there be any 'downsides' in doing this.

 

[oigle]

Maybe an issue with synchros. The hypoid may prevent the brass synchro rings from gripping. Time will tell.

 

[rifiki]

Many cars with manual gear boxes use use auto box oil, my MB 1960 190B has auto box oil.
Decades ago I filled the box with EP gear oil on Vauxhall Cavalier and it was almost impossible to change gear
when cold, not much better when warmed up.

 

[onefortheroad]

Can't see it being a problem tbh. Most oils change with temperature anyways.

 

[rayhennig]

Many cars with manual gear boxes use use auto box oil, my MB 1960 190B has auto box oil.

When my son got his 190D2.5 - manual - the gearchange was tricky. Drained the oil, refilled with MB Dex 2 auto box oil and normal service resumed.

R

 

[oigle]

Auto oil is fine for most boxes. Think you will find hyoid oil is not for reason I first stated.