The infamous 5th gear
 

The 5th gear strikes again...

My bike, a 3DS '89 (the swiss 3AJ)with only 41,000 km's and the 5th gear looks like this:

http://www.rtw.dk/5th_gear_pitting.JPG

And of course those bits of metal made a good job of the oil pump:

http://www.rtw.dk/oil_pump.JPG

Doesn't look like the previous owner paid any attention to Klaus's 4-5500 rpm in 5th rule...

[This message has been edited by AFrear (edited 23 January 2003).]

how did you get these pictures on here? I need to post some stuff and I cant figure it out!!!

Thanks,

Dave

http://www.horizonsunlimited.com/images/gifs/logo.gif

You host the image somewhere else.
You place the *full* web address inside "img" and "/img" markers, but you replace the speechmarks with square brackets like this [].

HTH http://www.horizonsunlimited.com/ubb/smile.gif

fifth gear fear (FGF), will it ever go away? it seems every tenere rider lives in fear of the german dive bombers visiting their gearbox...

still, i suspect that it is more bark than bite, and to paint with too broad a brush is misleading.

a mate of mine and myself recently completed an overlanding trip from london to cape town, and FGF was our main concern to start with. we had heard so much about it before we left, we had even been told that pretty much every tenere will get it over 30,000km, and that it was almost inevitable.

as my bike already had 50,000km on the clock BEFORE the trip, i was a little alarmed about FGF. so when i had to replace my countershaft in rome en route, i was rather pleased to have the opportunity to inspect my gears.

imagine my surprise to see that they were absolutely fine, no different to any of the other gears. i had considered replacing the fifth gear, but the italian yamaha workshop (who know the bike about as well as anyone, the tenere is much more popular on the continent than it is over here in the uk) told me that there was nothing wrong with my fifth gear and there was no point in replacing it. and this is on a 50k engine (the original engine too by the way).

my experience of FGF was further tempered in egypt, where i had the good fortune of befriending and staying with raed badder, who was egypt's top motorcross rider in the 80's and 90's - and mostly on the 1VJ yamaha tenere. raed knows the bike better than anyone i have met - with very little technical support during his racing days he had to in order to compete with the sponsored european riders of the day - and the fifth gear issue did not even feature in his list of the bike's weaknesses (which, for those interested, he listed as a CDI unit prone to breakage, a ppor cooling system, and a resulting engine prone to overheating). so long as the bike was ridden correctly, the gears should wear the same.

and this is really the issue - riding the bike properly. teneres are not meant to be ridden in high gear/low rev ratios; doing so will place unneccessary strain on the gears, and obviously they will encounter metal fatigue. and naturally, it is the higher gears that are going to show it first, as they are the ones which take the most strain due to this mistreatment.

the "correct" range to ride the tenere is supposedly between 3,000 and 5,000 revs, and to be on the safe side i tend to stay in fourth at high revs rather than go to fifth and strain the engine at lower revs. and by doing this i managed to do 17,000km in 3 months on a 14 year old 1VJ which started the trip with 50,000km on the clock - and the main problems at the end of the trip were in the top end of the engine, not the gears.

i do not doubt that the fifth gear doesn't give problems in a tenere, but the more i learn about it, the more it seems to me that the problem lies with the rider, not the bike. if you change the oil regularly (and that is OFTEN in an old bike) and the oil filter, and use all the gears as they should be used (i hardly ever use fifth around london for instance, there just isn't the opportunity to get the speed or revs up high enough to justify it), then you might consider yourself unlucky to have FGF coming to reality.

in reality, most teneres are going to have been previously owned, so if you do not know how the bike had been previously ridden, then you might do well to inspect the gears to start with, and if there is damage replace them - but once that is done, provided you ride the bike sensibly, you should be ok.

or get a 3AJ, where the gears are meant to be strengthened to counter the effects of poor riding. either way, keep the revs up and have fun.

http://www.horizonsunlimited.com/ubb/wink.gif

I have a 25 litre oil drum full of chipped XT600 gears - I can no longer lift it off the ground.
In 2001 I threw two of these drums away....

Good condition XT6 gears are the exception not the rule.
If you dont believe me you are welcome to come and have a look.
I also have Mike Stones (london despatcher) 380,000 mile 2KF here if anyone wants a nice low mileage XT.
David Lambeth.

Hope you can help?

I would like to understand this (5th Gear) problem a bit better, and hopefully somebody can help me with a few answers?

I have a 3AJ, and yes bought with unknown previous rider(s). The 3AJ has strengthened gears (re: Cabron, Tenere.CH history, etc...) however the original post (Afrear) has this later model (e.g. 3DS is the Swiss 3AJ).

Is the 3AJ just better placed, but all Teneres have the problem?

Are there hardened cogs available, or is "the fix" fitting the same spec cogs and riding carefully?

For all of us in the 'unknown', is there a way of checking, without a strip-down? Since the oil pump is affected, should we be monitoring the oil pressure (but how & what parameters)?

It would be good to have some guidance on this, and apologies if I have missed any previous answers on any of these points.

Thanks, Geoff

Quite an essay Carl,
But what you say makes sense to me.
I had my 3AJ's gears checked when I had the engine rebuilt and they were fine.
I also follow the regime suggested by Fred and like yourself find that I never use 5th gear in London, in fact I rarely use 4th!
Once you get used to riding in higher revs, if one accidentally accelerates in low gear, you can feel that engine straining and I always grit my teeth thinking, "shit, thats 5000km instant wear on the gears"

Geoff

Hi Geoff,

As Klaus and Cabron have said, the problem is more about the rider (or riding style). If you keep your revs up over 3k and under 5.5k then I believe the ‘problem’ wouldn’t exist. Having said that, these are not new bikes and it’s hard to see how previous owners have ridden them.

I knew this when I bought my 3DS and the following top and bottom rebuild was budgeted, I felt that for peace of mind I needed to know what condition the engine was in before I started taking trips RTW.

Starting with the top end, I had two valves that had shot oil seals which resulted in a large build up of carbon from oil leaking into the cylinder. The cylinder needed to be rebored due to marks and groves on the front wall (exhaust side of the cylinder). With the cylinder off it was my intention to inspect the gears (I have heard that this can be done) but I didn’t get to try it as I found out I needed to open the crankcase anyway. The conrod could be rocked from side to side, this meant the bearing between the conrod and crankshaft was done for and the whole crankshaft had to be sent to a workshop for repairs (Kedo.de). With the crankcase open I could finally see the gear up close, you can see it at the start of this post. The oil pump was also shot and the ‘strainer’(?) was full of bits of metal and instant gasket. All in all everything that could go wrong went wrong… (Almost http://www.horizonsunlimited.com/ubb/wink.gif

In other posts I have read that you can hear a screeching sound while riding in fifth gear beside a wall or fence. I tried this and couldn’t hear anything abnormal but maybe it requires a trained ear ? I affaid the only fire proof way to know is to open the engine.

Regards, Aubrey.


[This message has been edited by AFrear (edited 27 February 2003).]

regarding the issue of finding out the state of your gears, without opening up the engine, there is not really a way of knowing. you could check your oil filter for bits of shrapnel or even sieve your oil, but to be 100% sure you would need to open up and look inside.

i don't doubt that plenty of XTs have had problems with the 5th gear - as dave lambeth says, he has drums of broken fifth gears - but i do believe that if you start with a sound set of gears and ride your bike correctly, you shouldn't have major problems with them. obviously, this is not always the case, and when buying second hand one has no idea how the previous owner looked after their bike, so a gear inspection is a mandatory before a long trip - it's just not worth the stress or the anxiety of not knowing and constantly fearing that your gears will go at any point.

fresh gears + (3000 - 5000rpm) = happy tenere.

http://www.horizonsunlimited.com/ubb/smile.gif

"I had my 3AJ's gears checked when I had the engine rebuilt and they were fine."

Sorry Aubrey, maybe I should have clarified my statement better. WHat I meant by the above was that I had my gears checked when I first brought the bike for the same reasons you mentioned: old bike and unknown history.
Fortunately for me the gears were fine and I will try to keep them that way by being a careful rider.

Geoff