differential and gearbox oils

deQuincey

Quousque tandem...?
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BIO @ 43°15'46.5"N 2°56'03.7"W
according to manual for an stock coupe

gear box, 1,1 litres of sae80 not hypoid oil
final drive 1,5 litres of sae90

castrol has:

- ep80w manual Api gl4 for gearbox
- ep90. for final drive

what do you use ? i am afraid not all usa brands are available in europe
 
For gearbox I use 50% Redline MTL and 50% Brad Penn GL4 80/90
For differential I use 100% Brad Penn
 
Is this any good for differentials?
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I use Redline on both ends. I just looked at their website and they have the E9 listed to dial in what fluids are needed.
 
according to manual for an stock coupe

gear box, 1,1 litres of sae80 not hypoid oil
final drive 1,5 litres of sae90

castrol has:

- ep80w manual Api gl4 for gearbox
- ep90. for final drive

what do you use ? i am afraid not all usa brands are available in europe


more on this, as i have been searching on the different books and manuals


gear box, 1,1 litres of sae80 not hypoid oil -
no specs as to what API GL should it be, (GL 3, 4, 5 ???)
not hypoid may mean it should be GL3 ?
unknown
mineral or synth ? unknown

final drive 1,6 litres of sae90 - hypoid
again no idea if it should be GL4, or GL5
unknown
mineral or synth ? unknown
 
more on this, as i have been searching on the different books and manuals


gear box, 1,1 litres of sae80 not hypoid oil -
no specs as to what API GL should it be, (GL 3, 4, 5 ???)
not hypoid may mean it should be GL3 ?
unknown
mineral or synth ? unknown

final drive 1,6 litres of sae90 - hypoid
again no idea if it should be GL4, or GL5
unknown
mineral or synth ? unknown
I thought gl4 was safe for yellow metals and not with gl5....?
 
I would double check with Redline if you have a limited slip differential. I believe they will recommmed another gear oil.

they are readily available by email or phone to discuss specific applications.


yes LSD diff need different oil,

but again here are two issues as redline recommends gl5 for our differential and it might be incorrect
 
well this is what i have learnt,

so in principle, bith API GL4 for gearbox and diff

redline website offers wrong advice as to diff oil can not be gl5, be aware

p.s. redline does not sell their products here

i will keep using castrol, as i have checked mobil (they are all gl5), and motul (multigrade, non clear as to hypoid or not), and valvoline (no products adequate)

here are my choices:

gear box, CASTROL manual EP80W non hypoid, API GL4

diff, CASTROL CLASSIC EP90, hypoid, API GL4

basically i am keeping same oils as twelve years ago, nothing changes
 
DeQ, the differential oil can be (has to be!) GL5. Where GL5 causes problems is with the yellow metals (typically found on the synchros) in the gearbox.

What makes you think GL5 is not to be used in the differential?
 
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