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-   -   Anyone Experienced in changing dodgy 5th gear? (https://www.horizonsunlimited.com/hubb/yamaha-tech/anyone-experienced-changing-dodgy-5th-41350)

Pawlie 8 Mar 2009 06:54

Anyone Experienced in changing dodgy 5th gear?
 
Ok. I'm heading to the HU well of knowledge once again. Thanks in advance to anyone who can provide solid info on topic discussed below.

This winter I have been undertaking a complete tear down of my 43F (for europeans) Plain old xt600 1986 for us N. Americans. I have been communicating with Dave Lambeth about this project. The problem is I just got an email from Dave saying he is out of contact for a month due to being in africa at the Tuareg Rally. Fair enough, can't deny anyone out having fun!

The problem is I don't know what parts I need to upgrade the 5th gear as often mentioned here.

Is there anyone who knows exactly what parts, and Part#'s, I need to do this job? Some helpful directions to steer me along in the replacement would be of benifit too. I do have the Clymer manual and have disassembled the motor to the bare cases at this point. I seem to recall that the bits needed are standard Yamaha bits, just from a later model?

It's going to kill me to have to wait a month to get parts! Not only that but there are engine parts strewn all about the house. It's best for all in this household if I get to this project promptly.

Many thanks,

Pawlie

bubbla 8 Mar 2009 16:21

Hej,

maybe this will be helpful for you:

Change sprockets pairwise. You will need two for the fifth and two for the second.
(second on clutch axle is pressed - but needs to be taken off to replace the fifth – dont’tuse it again!)

Make sure to measure distances and directions for second gear before taking it off the axle! If you don't know how to handle the press off/on than better ask a motorcycle or car workshop - with the right tool it is a less than 10 minutes job.

Check always condition of oil-pump and net-filter of pump intake befor you start to assemble the engine. Good oil supply is sooooo important for the bike. I never do a gearbox job without an oil-pump change. Upgrade it anyway if the pump is still a 5Y1-type.

By using the original parts for your kind of engine (43F) the gearbox should be good for a lot of miles.

The cheapest way to get more miles out of it: don’t go on too low revs in the fifth, and change the drive sprocket (15 now?) to a smaller 14.

Steps to an enhanced gearbox:

Yamaha used better gearbox sprockets when they start to deliver the XTs with e-start. As far as I know you may use these sprockets on your old axles (drive chain sprocket axle of updated gearboxes cannot be used because it is longer)– but you need to replace all gears.

On the later XT 600 Z 3AJ model (the one with the silver engine) they rised also
the turning speed (faster = more oil supply) of the gearbox by change the primary drive to
34/71 (yours should be 31/74). To upgrade your gearbox you need the clutch axle, the clutch
and the primary drive sprocket.

And again - an important and highly recommended update for the whole enginge would be to replace the oil pump – take the latest model (5-hole pumps work in 3-hole models).

Good luck!

Tenere Tom 8 Mar 2009 18:33

I bought my Tenere with a dodgy 3rd gear - basically I had to double shift up and down.

I just did a gearbox (internals) swap. Not a job for the beginner but not that hard compared to multi-cylinder bikes.

It's a shame you aren't in the UK as I have a 5th gear that may be of use to you.

skip 10 Mar 2009 10:10

Hi PawlieWith regards 5th gear you will need to change not only the 5th gear but also the 5th pinion gear some time's called a dog gear, these are mated parts and when one wears the other wears, you will probably find wear on one side of the teeth on both gears. As you have the engine a part it is worth checking the other gears and the amount of play and wear in the gear selectors as well as the shift cam, as these do wear and break, i had the 5th gear selector go on a trip in Morocco it was a long slow ride back to England.
As the others have said up grading the oil pump is a good idea, as well as just giving all the internals a good check over, bearings, shaft's, oil ways and the casing's them selves. Have fun Skip

Pawlie 11 Mar 2009 06:06

Hi Guys,

Thanks for the helpful tips. I did the oil pump upgrade a while back and have been careful to not load the 5th gear at low revs.

I have taken the bike down to the cases but as some of you have recommended the gearbox bits are best examined by an expert. An expert, I am not!

Here in North America we got the first generation electric start model starting from 1990-1995. From what Bubbla posted it seems these bits are not a simple swap in. Would these parts be better than the 43F generation ones?

Any chance someone knows exactly the bits required? Part #'s?

If not, I'll just have to get used to waiting for DL to get back from his adventures.

Many thanks for your help/suggestions so far.

Cheers,
Pawlie


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