GEARFOX BUCKED!

I see the numbers on the oil bottle. I suggest you use an oil with 50 as a last number, also one with plenty of zinc in it.

@Neville Lush, I have read that SAE 15w-50 is favoured by some owners.
The Triumph dealership uses Fuchs Silkolene Fully Synthetic 10w-40, so I went looking for the best I could find in that range and discovered Amsoil, whose oil surpasses the general requirements. Mobil 4T seems to be a favourite too.
 

And that is exactly why I did it All my self mate...

Specially with warranty jobs dealers do rushed jobs.

They charge a customer 100-150aud but triumph pays then only 40-50aus an hour. The dealers are pretty much working at a loss with warranty jobs.
 

Mate feel free to ask me anytime. I recently rebuilt mine. Happy to share information.
 
Triumph themselves tell you to use 15/50 in temperatures above 10deg C. Somewhere in the mighty document that is the workshop manual there is a lubrication chart with this info. I use it in every Triumph triple and twin except the little triples and in every instance the owner has reported better gear selection and clutch operation and a quieter engine. In one or two far north Western Australian bikes, I know guys use a 60 wt top number due to very hot conditions and long high speed rides with higher powered bikes. On pg 136 of the manual it says either 10/40 or 15/50 oil, but does not say why. I have seen the chart/table however, and obviously used the 50 oil and found it better.
 
I'm about to change to 15/50 and will report back here at some point. 10°c would be about as cold as it gets furing the day where I live
 

Just look what they did to this guy's bike...
 
I mean, it does not matter how many Harleys blow up the gearbox, it will not make any difference to a person with a Triumph. The discussion was about a Bucked Gearfox in a Rocket, not how many Harley boxes broke. What does it matter ?
The point TRIUMPH was making to me was all the bike makes have gearbox failures that are more frequent than TRIUMPH I was complaining to them that the ROCKET forum had several owners complaining about the trans problems so what could they do to give more support to the loyal owners that love the bikes