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-   -   Gearbox Upgrade on a Tenere 34L (https://www.horizonsunlimited.com/hubb/yamaha-tech/gearbox-upgrade-on-tenere-34l-54203)

Bugz-101 9 Dec 2010 12:24

Gearbox Upgrade on a Tenere 34L
 
Hello fellow Tenere heads,

I am nearing the end of my Tenere 34L rebuild and have left the worst til last.... I have now split my cases to discover a knackered gearbox (no suprises!

It has the original oil pump which needs to be replaced. For those Tenere adicts who want a refresh check out this link on the HUBB http://www.horizonsunlimited.com/hub...ce-needed-5769. Given I have a 34L, this link recommends moving to a 1VJ oil pump which is 50% greater output than the original 34L. However I am tempted by the 3AJ pump whic his double the output than the original! Its even cheaper at just over $100USD from Park Shark.:thumbup1:

My next problem is the gearbox. The gears on the countershaft look very useable, certainly no chips and the hardening hasn't broken through. The mainshaft is a different story with two gears well and truely knackered. Perhaps the previous owner replaced a couple of gears on the countershaft as things don't really add up to me. Problem is I think the whole mainshaft has to be replaced as one unit ($$$) and I don't think its available anyway.

Has anyone fitted later (XT600E ?) gearbox internals into such an early model? I hear the hardening is much more durable, the ratios are better and the oil delivery is better. (Especialy with the 3AJ oil pump)

I'm sure others have been here before ?

Many thanks,



MARK.F 9 Dec 2010 13:05

I was faced with this problem a couple of years ago.
I was rebuilding a XT600 43F,same as a 34L apart from tenere tank/seat /sidepanels.On my bike all the gears needed replacing as they were were starting to pit:stormy:.
I ended up taking the expensive route and going to Dave Lambeth.
I only live a couple of hundred miles from DL so I decided it would be better for me to take the motor to him,he fitted a later gearbox modified to fit in the cases.Dave rebuilt my motor with the later oil pump and a host of other stuff done,rebore/new valves etc.
Obviously this is'nt practical for you, but you should ask him how much would it cost to get the modified gearbox sent to Oz.
If you do'nt want to go down that road,you could always fit the original gears & replace them again when they start to wear,obviously that's just swapping like for like.The oil pump is a straight swap.
Here's a link to the rebuild My XT600 project.. - ADVrider
Mark

Bugz-101 9 Dec 2010 14:25

Cheers Mark,

I've just double checked the Partshark website and I can get the dodgy gears replaced for a few hundred bucks and just whack it back together.... hhmmmm.... :confused1:

Great thread you have there - I'll re-read that one later and comps on the photos.

I see you went the 3AJ oil pump - so if Dave is recommending that then I'm sold :smartass: I might fire him an email and see what the damage would be for the upgrade. Nothing that can't be done with some international freight. I wouldn't send the entire bottom end - just the shafts so it wouldn't be too bad. I know he's a busy guy though!

Do you know what Dave put in with the gearbox?

MARK.F 9 Dec 2010 16:28

Sorry Bugz,I forgot what specific parts he put in the gearbox.
One thing I can remember was that on the clutch side of the crankcase, one of the gearbox bearings was worn-out & he reckoned that every time he's split the cases this particular bearing is shot,so I'd check the gearbox bearings before you go shopping for spares.
Mark

kenymact 9 Dec 2010 20:16

I replaced my two 5th gear wheels when the whining started and its pretty straight forward,I found the gears from my yam dealer were very well priced and now its as good as new........

Bugz-101 10 Dec 2010 15:46

Thanks guys,

I figure I will keep it simple and replace the gears. The shafts look great and I have done the maths on ParthShark.com

If I can find someone to split the mainshaft I will replace both pairs on the 3rd 4th and 5th gears. Cost for the bearings would be $378 US which isn't bad for six gears!

I'll replace all the bearings (apart from the one on the crank half that can't be removed) so with a high output pump it should be good as new :thumbup1:

Bugz-101 27 Dec 2010 15:15

Clutch Actuator Bearings
 
Hi guys,

I am preping the cases to be blasted and painted. All the bearings have been removed apart from the Clutch actuator bearings!!! These are the two needle bearings, one at the top of the case and one deep within.

Anyone got any ideas? I have tried gently heating the cases and using a long coach bolt with the head ground flat but I just cant get enough grip - and thats the top one! I can't think how to get the bottom one.

I'm replacing all the bearings and its gonna be a pitty to do all this work and not replace two little ol' bearings!!
:helpsmilie:

Bobmech 27 Dec 2010 21:53

Depending on how much access you have, one way to remove needle bearings in a blind hole is to remove the needle rollers, then use an arc or mig welder and weld a bead around the inside of the bearing outer shell, but be carefull not to blow a hole in it. When the weld cools, it shrinks the bearing shell and is easily removed.
Of course you will have to replace the now damaged bearing with a new one.
The other option is to use a small slide hammer with a suitable attachment.
Bob

Mezo 29 Dec 2010 09:36

Put the case in the oven & let it bake & it normally just falls out of its own accord, or pick it up with oven gloves & give the case a good tap on the floor.

Mezo.

pete j 31 Dec 2010 15:26

XT transmission
 
Hi Bugs,

Been watching your thread as i'm also busy with a gearbox.

After much research i have yet to find a well documented post on what is possible to extend the life of the transmission, especially 5th gear. There are many threads but little specific, no part numbers and often the final solution to a thread is not posted!

No doubt Yamaha have a system that traces when and where changes take place and where they are applied, i've yet to find it. That the prefix is taken from the 1st bike to use the part is inconsistent and, what about all the non-prefixed numbers? :confused1:

I'll share what i've found, certainly not conclusive as this is my first XT, and from other posts and manuals, this is what it looks like:

Predominant troubles posted are short 5th gear life, oil pump damage from tooth debris leading to piston failure, lack of lubrication.

Early bikes had carry-over gears and oil pump from XT550, 5Y1 and 'splash' lubrication.

4 mods were done:
better gears
better lubrication
pressure fed lubrication
2nd upgrade to gears

1VJ got the 1st upgrade to some gears and a larger oil pump, 6mm. Also, maybe oil jets inside the case, fed from low pressure side of oil pump. These jets can be seen in both sides of the case fed from return line to tank via a gallery over the gears. My '87-'89 2kf has them.

Possibly the next change was an external oil pipe from the pressure side of the pump to oil jets over the gears. The oil pump was again enlarged, now to 8mm.

This was applied to 2nd version of 3AJ, 1989? There is evidence the black cases did not have the pipe and the silver cases did.

The next upgrade may have taken place after 3AJ. The 2JT 5th gears were used in the 600e, but are now what we should use. Ask for them or you may get 1VJ like i have.

In fact i believe one can order gears off the 3TB lists, the gears probably remain the same to the end of 600e. The output shaft is too long for a kick only bike but may fit an earlier e start. The output for early bikes (2 bolt) is obsolete but the 2kf one (fine spline, nut and lockwasher) should fit kick versions.

A final mod was made which i believe only happened on e bikes but may be able to be used: The ratio between enging output and clutch was changed to run the transmission at a higher speed thereby reducing torque load. Requires a lot of parts to change, including different sprocket ratio. Am not an engineer but not convinced this does any good.

Everything before it does.

I don't think 34L, 43F or 55w will have the jets cast in. Some fine engineering will need to be done if not.

It would be useful if those who have cases open to post your findings and model, or add your knowledge so we can build a good database once and for all.

My '88? 2kf does not have the external pipe but does have a cast 'knob' on the right hand case over the gallery mentioned earlier. I will be able to add the pipe by some careful drilling and tapping. The gallery will need to be blocked right at the clutch actuating shaft end to separate the 2 oil supplies.

It would be useful if those who have cases open to post your findings and model, or add your knowledge so we can build a good database once and for all.

I hope this does not sound too technical. I know a few pics would help. Prob is my smugmug learners has expired and i've yet to dicover the rules around a smug account and what happens if you stop paying?

I welcome all contributions, am happy to post the results to a popular forum.

Thanks,
p

Bugz-101 1 Jan 2011 15:04

4 Attachment(s)
Thanks Pete - you've done some great homework!

It is a real shame that there isn't more documented fixes on this topic. Its such a popular model and the flaws are very well known.

A few pics for you whilst I had the camera handy.

The sump pickup was amazingly full of crap. So many bits of gasket glue, gasket material and chunks of metal! I beleive there is a self disolving loctite which would avoid this problem... just not sure which number it is.

My cases have been replaced at some stage in the bikes life as they aren't even stamped with an engine number but I beleive they are 34L cases. Stamped with part number 5Y104. These cases do have the single oil jet on one side and a double on the other.

I have been putting off ordering all my bottom end parts, whilst I try and research the gearbox issues. Spending so much cash it would be nice to think you would be overcoming some of these design flaws by putting in latter model parts :)

Any other Tenere experts want to weigh in on this debate?

Bugz-101 1 Jan 2011 15:35

1 Attachment(s)
Pete, BTW, you can easily just use the paperclip icon to attach photos as I have done. No need to have them hosted on the Interweb but they just appear lumped together at the bottom of your thread.

It can be a little hit and mis though, so just make sure they attach with no errors and preview your post :thumbup1:

pete j 1 Jan 2011 18:54

Hi Bugs, ta for advice, will get to pics. Had a productive day and learned new things.

Your left case is same as mine but i believe the right will be different somewhere. Mine is stamped 2kf, but the 'jets' in your pics look the same. Interesting, and confirmation i was wrong. I thought that came later.

Today a friend taught me to use google to search inside forums.I long ago gave up HU search in disgust, but knew from posts that more was there.

Also, returned today to: www.XT600.de - Die XT-Werkstatt

The site has all knowledge we need but is in German, and a bit tricky. Translators, used 2, are worse than trying to understand the original. Did some sentence by sentence work that worked better but *very* slow.

So, if we have a translator boffin on board or, a fellow restorer/fixer comprehendo Deutsch can help, be very nice:biggrin3:

[url=http://www.xt600.de]www.xt600.de xt600 xt600e Tenere T

If you like, see the the 3rd paragraph in link above, pic 2 (bild 2) is of an extra oil jet drilled and tapped over 5th gears, fed with cool (er) oil overflowing from tank.

p


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