Shell spirax

More than likely, it would have.
Change back to the recommended grade and check the difference..........if any.

It's the only way to find out for sure.

Disco
(aka Tony)

Two issues here, weight (viscosity), and API rating (GL4 / GL5)...

Nissan recommend 75W-90 API GL4

It is generally accepted that GL5 oil should NOT be used where GL4 is specified.. something to do with the extra sulphur in the additive package eating the yellow metals (brass/bronze) used in the synchros...

On that basis alone, the Spirax A (GL5) is incorrect, and I wouldn't be leaving it in there long term...

On the issue of viscosity, I've found that the 75W- bit to be the key in eliminating (or at least greatly minimising) that annoying "cold shift baulk" ..

The Spirax G is the correct GL4 rating, but there doesn't appear to be a 75W-90...
The 80W-90 would be fine once warmed up, but possibly/probably a bit notchy when cold....

Regards, Ed C

:)

Thanks for that fellas. I am definitely going to change to a gl 4 oil, preferably Castrol; as I have read where wrong oil in a gearbox will cause hard shifting and these boxes have a lot of mileage on them. I suspect also that changing gears as if in a car, wont help the matter either. This is the third box that i have had, since the replacement last year seem to decide that shifting to fourth would be a major problem (like the first).