Gearbox freshenup

[petejw1966]

it can be a bugger to get out sometimes,
it has an o ring around it,
needs a bit of twisting and a screwdriver behind it
and it should come out, from memory i think i removed
it with the starter in place.

hey geoff,
 when i was messing around with my carbs
when they were running on the rich side it had a
vibration around that rpm mine was around 3500 - 4000rpm
if it does it under acceleration, i found i was running the floats
a bit rich.  at cruise check mixture screw adj/ air filter clogged/carb sync.

when i was to lean on the floats around that rpm under accel
i was getting  an engine knock.

[steptoe]

 Coops,, the end cap is the holder for the main shaft of the gear box,,

the hyvo chain comes off the crank onto this shaft that also holds the starter clutch,,

a good tip Pete, will also look at mine,

have a small vib between 3600 and 3900rpm,, in every gear

[Christian Raith]

UM.......Coops we really don't have a winter so better do it now 

[Cooper]

Thanks for photo I'll check it out tomorrow had a ride yesterday gearchanging is smoother maybe as a result of heavier oil and clutch adjustment has helped. This may be a job to do next winter Coops.

[petejw1966]

hi coops,
another thing to check,
not sure what its called, it sits ride beside the starter motor
on the left hand side and carries a bearing, i went and pulled my one
out to polish the outside and the bearing was shot,
didnt notice at the time if it made a noise but might be worth while
to check out.



the bit in orange,
can be a bugger to get out, but it will come,
might be worth a shot.

[steptoe]

ALWAYS check oil levels, at regular intervals

   

[Cooper]

Thanks Steptoe been away from computer so delay in your response. Yeh no smell oilis good and no funny bits floating around I put a tad heavier Penrite gear oil and readjusted gear change and clutch which was not in the right position will give it a run tomorrow and see what happens. Might take up offer on gearbox if we feel it need s a  change,  not sure what is replacable and still obtainable in old gearbox from Yami dealer until we get at it [if we do] Thanks Coops.

[steptoe]

before you get to nevous Coop,,

pull the end cap off and check,, was thinking about this today,, maybe even drain the oil that's in the drive, into a very clean container, check the condition of oil, even smell the oil, against new oil, if a bearing is going, it will be getting hot, which will burn the oil, and burnt gear oil STINKS,, even put a small magnet in the container to see how much metal and how big the pieces are, {can't remember if a magnet is on the drain bolt,, if there is, that will tell you}

if there's only the tiniest bit of "sludge" on the magnet,, maybe refill the box to the top to make sure the large rear bearing is bathed in oil, and spin to see if the "grind" goes away,, there are stories of these running dry some how, then drain out to proper level,,

give it a go first before giving up straight away 

if worst comes to worst, I have a spare box

[Cooper]

I get the picture now and thanks evryone for comments its a very involved job not sure I have the gumption and skills to do gearbox from that angle maybe I'll look out for another gearbox and do a swap at least can achieve a result now wheres the gearbox coming from?Regards Coops thanks all

[pgnz]

If you whip the bolts out, then  the lid comes off,  there's a nut underneath to undo, it's notched to the shaft so you have to hit it with a screwdriver and hammer to un-pin it,  bearing sits underneath, that outer bearing is a thrust bearing,  it's a cage with loose ball-bearings,  trouble being you have to remove the whole drive unit to remove the circlip on the other inner bearing to knock the whole shaft out,  the inner bearing slides outwards because it's not an interference fit but that outer bearing is locked in solid,  it'll come out with the whole shaft because it's supporting case is just slotted in and slides out with it,  a big hassle because you have to strip the whole middle drive to access it and that involves buggering up the pre-set gear lash adjustment...  might be easier all-round to try and score another whole unit if the bearings are fekked,  if you whip the lid off though you should be able to check the state of that suspect thrust bearing and go from there

[Cooper]

Thanks mates yes tried screwdriver tact its coming from middlecase the round cap 4 allen screws I believe theres a bearing behind manual says circlip holds inplace is this easy to withdraw it may be if Im lucky just that bearing thats the culprit the book talks as if the motor is out  and obviously easier to get at Coops

[steptoe]

if it sounds like middle drive,, have a go at Xtrians' idea,, there's several bearings in there,,

a big one that the middle box locks into in the motor, which is a cases apart job, or the bearings in the middle box, which would be a whole lot easier to do on a bench,,,

be very,very carefull,, there are normally shims in there,, to do with backlash on the gears and all that type of thing,, take a lot of notice how it comes apart if you do it your self

or take it to a better than half way decent mechanic

if you think it's the starter, it doesn't move once the motors running, or even rolling over the floor in neutral,, wouldn't hurt to pull it apart and clean it any way,, a very easy job,, put texta marks across the joins, so it goes back the way it came apart, 3 thin long bolts, and the rest pulls apart and pushes together,,  a small bearing either end of that too

[Christian Raith]

Get a long screwdriver and put the handle in your ear and just poke the end onto different places on the case. You may find were it is the loudest.

[Cooper]

Smee again sound of worn bearing positive its coming from the middle gear area left hand bearing support Im off to work now but when I get chance can get the cap off is the bearing easy to replace book says circlip remove and bearing taps out thats ok when engine out but is it possible  while inplace many thanks coops.

[Cooper]

Many thanks Steptoe its definately around gearbox area I'll check first all what you suggested thought it might be starter related and check bearings what I can get at .,I got onto UK site and it appears some have gone thru sump with engine inplace I suppose thats Ok if the bikes on a lift so that you can see in and up but I'll do easy stuff first Regards Coops