Technical Gearbox oil

[joipalli]

From the manual for model 2001 it says the gearbox oil should be SAE75w90 that passes GL5.
Then the manual from this site: http://www.nick.hostwith.me.uk/multipla/stuff.html
States 75W-80 that passes GL4

Is there a different gearbox in the younger models or have they change the oil requirements ?

 

[joipalli]

I've had Mobil1 SHC fully-sync 75w/90 GL5 in my box for few thousands km, not happy with it, to much grinding in 2nd when cold.

Changed to GL4 75w/90 GL4 with these specs:
API GL 4, MIL-L-2105, Volkswagen 501.50
75W-90
cSt @ 40ºC 64,2
cSt @ 100ºC 14,0
Viscosity: 228
Pour Point, ºC -42

Thinner oil, but so far I'm satisfied. I almost can't feel the notch in the 2nd when cold. Have already driven 1000 km with it in.

 

[conanhoward]

its not really the oil its your syncromesh rings that are knackerd

 

[Peter Pick-Up]

I've had Mobil1 SHC fully-sync 75w/90 GL5 in my box for few thousands km, not happy with it, to much grinding in 2nd when cold.

Changed to GL4 75w/90 GL4 with these specs:
API GL 4, MIL-L-2105, Volkswagen 501.50
75W-90
cSt @ 40ºC 64,2
cSt @ 100ºC 14,0
Viscosity: 228
Pour Point, ºC -42

Thinner oil, but so far I'm satisfied. I almost can't feel the notch in the 2nd when cold. Have already driven 1000 km with it in.

Both oils have the same viscosity (75W90), so the new one isn't thinner at all!

 

[joipalli]

Both oils have the same viscosity (75W90), so the new one isn't thinner at all!

Taken from the Maintenance World
...The most important property of any oil is its viscosity, which is defined as its resistance to flow due to internal friction. The two major viscosity measurements used in engine oils are kinematic and absolute. Kinematic viscosity (KV) is oil’s resistance to flow and shear by the forces of gravity and is typically expressed in centistokes (cSt) or mm/sec2...

The latter one GL4 has a lower cSt rating, this is interesting reading on the maintenanceworld site.

 

[Peter Pick-Up]

You couldn't possibly feel the difference in the real world for sure...!!