Gearbox oil alternative.

I've just done a gearbox build, and have read on the Triples online forum recommendations for using Redline superlight shockproof gear oil in the Trident gearboxes. Apparently it improves shift quality. In the sales blurb, it is described as a "75W90 gear oil with the viscosity rating of an ATF."

I am aware that 90EP oil is recommended for our gearboxes, but this is listed as a 75w90. Can anybody explain to me the 75w90 gear oil term?

http://www.redlineoil.com/products_gear ... tegoryID=6

Has or does anybody on the forum use this, and has there been any noticeable benefit.

I use Amsoil 75W/90 Syn in my box. Gear oils have a higher numerical rating than engine oils since I believe viscosity is measured at different temp range. Loosely speaking a 90 weight gearoil has similar high temp (100c?) viscosity to a straight 40 engine oil, something like that I think. An oil expert can tell you for sure but 75W/90 seems to be accepted norm to replace EP90. That Amsoil has improved my box and even the seals don't leak (k/s lip oilseal, std 'O' rings on gearchange and indicator shaft) something I was told would happen with full syn! Here's a good site which explains more https://www.opieoils.co.uk/technicalinfo.aspx

Hi reggie,

I still use EP90, even in the quaife boxes, but I do add a bit of Molyslip for good measure!!

I love Redline products and use their Shockproof gear oil in my other bikes BUT it is GL-5 - supposedly bad for yellow metals - so I use their MT-90 (which is GL-4) in my Norton's gearbox.

Royal Purple has an oil that has a GL5 rating that is non corrosive, (So they say) A few people I know have used it and say it's great oil? Have a great day and just be sure to use oil.

I'm using the Redline in some stuff but in old boxes the Royal Purple. In my BMW car I can feel the difference for sure, in my bikes I think it is a bit smoother. The difference is most noticeable on a cold day. I have no seal problems to report and have only been using this stuff since 2001 so no problems like premature wear have come up.

Thanks for the replies everyone.

Briank wrote

it is GL-5 - supposedly bad for yellow metals

Click to expand...

Mmmm, I thought there may be a catch. I've just put new bushes in the gearbox, and don't want to dissolve them. I'll look into this a bit more.

GL5 is only an issue if the oil temp goes over 100 Centigrade, as the oil normally goes all white in the uk from water emulsification that says a Norton box gets nowhere near 100C.

I seriously doubt that you'll ever have to worry about GL5 gearbox failure.