I ran 85/90 in my 128s. Napa 85/90 with a bottle of Lucas is what I am using in my 5 speed.Would like to know what oil grade are you guys using on your 128 transmission.Thanks
The GL1, 2 and 3 specification was phased out almost twenty years ago. It's a good bet that GL1 is little more than a marketing name these days.
The viscosity of NAPA GL-1 is very close to the same as Redline MT-85 (at 100 degrees celsius). I've never used MT-85 in a Fiat transmission and I haven't heard of anyone else using it either so I can't say how well it works. GL-1 is outrageously thick at room temperature which is one of the reasons why so many people don't like it.
Apologies for the thread hijack question but how much transmission oil is needed for the 128 box?
Cheers
Jamie.
ps I'm away with work and away from my manuals!