Gearbox Oil

[jonno]

Just swapping gearbox as mine decided to stick in 4th gear. Dropped the oil in the box i'm going to use after undoing the fill plug

Its a 4 speed petrol box, what oil should i use and how much goes in?

Jonno

[CovKid]

GL4 rather than GL5 and until it trickles out of filler hole. The thing you do need to make sure of is you can get filler plug out - lots drain gearbox then can't remove filler plug

[faggie]

if you want the best mobil shc it must be good as mines still going and its got a couple of engine tweeks for more bhp

[jamesc76]

gear box on petrol is 3.5 ltrs on a derv its 4, after speaking to Aiden over the weekend (hava a new box from him) He advised me to put 4 ltrs in it, and it shouldnt spill out !

[jonno]

Thanks for the replies,

Covkid i had seen that advice before and made sure the fill/level plug came out, it was a tad tight and my box was out the van.

I'll see if i can get the 4 ltrs in James.
Will have a look about and see what GL4 is available.
Thanks
Jonno

[Red Westie]

Early manual VW gearbox's use yellow metal in their syncro hubs which can react to oils containing sulphur based additives used in both GL4 and GL5.
The damage apparently occurs at higher temperatures and over many miles and although both specs have this additive, GL5 has much more of it (more then twice the amount) to improve it's 'SHEER' characteristics to meet the demands of the higher spec (as for hypoid gears in differentials)

From what I can gather from my enquiries (phoning several oil companies) this was more of an issue with early GL5 spec oils and later types are not as bad (remember both GL4 and 5 have these additives anyway) and that the general concensous was to either use a heavy weight old fashioned GL4 straight 80 weight or 80W90 IF YOU CAN FIND IT in a GL4 spec! (not many suppliers stock it now) OR a modern lighter weight SEMI SYNTHETIC (75W90) that shows BOTH SPECS GL4/GL5 on it's label (Carlube do one for instance) which means the oil has passed both specifications and not just GL5 (although as we all know this is the newer spec it also meets all the criteria of the old spec).
I believe that Aidan Talbot (gearbox specialist) uses the later (75W 90 semi synthetic showing both GL4-GL5 spec on the label) and thats what I would recommend for our 4/5 speed manuals.

Martin

[jonno]

Martin, i think i'll go for the 75W 90 semi synthetic showing both GL4-GL5 spec on the label if my memory is right thats what the local GSF has in.
Thanks
Jonno