XT 600 Gearbox new or old version?
 

Hi

There seems to be a little confusion around on the web, on whether or not the black engine XT 600 3aj is with the upgraded gearbox where the 5 gear problem is eliminated. Some page say that it is only the silver colored ones that have the newer gearbox.

I notice on my black colored engine. that there is a oil line on the outside of the engine, from the oil filter housing and going in to the gear box. The earlier engines did not have this oil line. Is this the way to tell if it has the new gearbox or not ?


Christian :mchappy:

Hi Christian
Good question/observation to which you will probably get many varied answers. Only Mr Yamaha knows the full answer. Do not forget there are engineers out there who have made (and sell) improvements to this bike and its engine. Alternatively a PhD paper on the XT 600 might unearth the whole story.
Yes, the 3aj some upgrade (oil pump inpaticular) which explains the extra oil line, thus giving greater lubrication to the gears. The gears have been upgraded but I think you will find that this came later in the 4pt and these you can (so I understand) be fitted to your and other earlier XT's.
When it comes to the gears, the problem is greatest with the 5th gear, but includes others. this is mostly due to the abuse inflicted whilst in 5th at low engine revolutions, combined gear change (stress). If you look at updates on later XT's the clutch housing changes to the right of the bike!
The colour of the engine (it is suggested) makes no difference other than the colour, it is said. However I think that it unlikely.
I suspect this is not the answer you seek. Yet I hope it helps.

Oh and :welcome:

Socks

thanks...

that was the answer i was looking for. :thumbup1:

Pretty sure that the model before the 4PT, the 3TB, had the improved 5th gear as well. At least I remember someone telling me that mine didn't need the upgrade. Mine has the clutch on the right of the engine.

I found the answer on http://www.rallye-tenere.net/Stamb_xt_600_z-3AJ.htm

# With the 3aj 1989 model the primary drive has been changed to minimize wear .Then the speed is increased in the transmission, this of course required a revised final drive ratio, the most at a constant pinion sprocket
a difference of 5 teeth more accounted.

Moreover, now the fifth gear with extra cooling oil was supplied "direct lubrication", which reduce the wear significantly, due to lowered temperatures .
This method had prevailed until the end of the XT Series 2004th #

Translated from german.

Christian

The last post from Christian is close to my understanding.

The Tenere 3AJ came as a series 1 and series 2. The series 1 had a smaller oil radiator and the old gearing. The series 2 had a larger oil radiator and new gearing, etc..

This link may help: http://www.horizonsunlimited.com/hub...-gearing-25500

I wonder if the oil pump upgrade was at this time too, or did the series 1 also have the new oil pump?

Geoff