Gearbox removal and repair

[bbrown]

Hi all,
I am a newbie at this and never done any major engine work.
I figured I would do a write up cause it may help somebody else (newbie).
The idea is to fix a bike I purchaseda couple of weeks ago, I bought it off the PO with the knowledge of a problem in the gearbox.
He said he was having trouble with second gear so he took the bike to the local Yammy dealer.
They found a small piece of metal stuck to the drain bolt, they guessed it was a piece of a gear and without taken engine apart they could not tell.
He took it home and never drove it till he sold it to me.

So......
Take the engine out!
Pic 1 and 2



Remove crankcase cover of the alternator, remove drive sprocket, chain guard, undo two long screws on the alternator then carefully unclip wires from crank case.
Then remove strator.
You will need a flywheel puller for the rotor off do not order this tool.!!!
Pic 3
you need a special coupler nut which is not easy to come by.
the tool you need is part # 35-0040
So now you work on the primary drive cover, even thoug oil is drained you will get oil coming out when you crack into the primary, put some rags down (I think somebody on here said diapers work great)

Remove oil filter housing first then remove the case.
Pic 4
Remove clutch bolts ,springs and washers, they can be a bitch so use a impact!
Pic 5

Remove pressure plates, keep in the same order!
them remove mushroom head clutch pushrod, the bearing ( with a magnet ) and the main pushrod.
Pic 6

Question , should the mushroom pushrod have a mark like this?
pic 7

Ok so I have an issue with putting money out for a tool that is a old part off a clutch with two pieces of metal welded to them! (probably cause I didnt have an old clutch plate either,lol) so I though about a strap wrench, it worked like a charm, was only 10 bucks and I can use it for other things not just a clutch of a yammy!
pic 8
Remove lock nut on clutch and pull off clutch center,thrust plate, bearing.
Pic 9

Then clutch drum, bearing sleeve and washer, all to be kept in the same order, very important! (zipty thru the center works)
Pic 10
Now to start with the gearchange, pinion and kickstart removal.
pic 11


anybody know how to insert pics right in the paragraph? so I do not have to number them.

 

[bbrown]

Hi all,
Figured I would update and add more pics.
Woohooo got the manwell, should make things go quicker!
Decided to not take off kick start, seemed like a nobrainer to leave it in.

* Not sure if you need to take off*

For the gearchange shaft,take off the eclip on the on the clutch side, unlatch from kicker side and slide out.
pic 1


Remove pinion gears (mostly to get at that case nut)
and starter if you havent when you removed engine from frame.
Pic2


Should be ready to start removing case nuts, 4 on top and the 13 below and 1 behind the clutch. (yes ,u should remove in order 18 tru 1, i just cracked it first then went back finished)

pic 3


After removing the 18 case nuts I hit the engine with the heat gun on low and attached the motor mount bolts and a couple of tie down straps to them, then a ratchet strap to the front mount and slowly put pressure on as I hit with a rubber mallet, took about 5 min and came apart easy.

Pic 4 5 6





And the culprit is.....




* not sure if you need to take the kick start and the shoulder bolt plate of the gear mechanism, i did not take kick start but I did take the shoulder bolts and locating pate off, maybe somebody whom is much smarter and more experienced than me can verify.


So while I have the case open I am going to the 5 gear overdrive as well as the 1 piece clutch rod.
Any other upgrade that anybody else know of?
Order the parts and gaskets then wait....
So far

 

[retiredgentleman]

Some good pictures there. Looks like you have found what you were looking for.

While you have the engine opened up, you could replace the 6 clutch bolts with allen heads. Much more friendly than those phillip heads. XS650direct part # 39-6504. Some of the members have been making up their own cap bolt conversion.

 

[bbrown]

Thanks Retired,
They where a bit of a bugger to get off!

 

[bbrown]

Parts are here! woohooo, could not get the overdrive gear(not in stock) bummer.
Mikes XS Parts they did have :
-5th gear
-gaskets
-Oil and sump filter (heard problems with this but mine was fine)
-clutch pushrod long and new bearing


Love that I can order parts for an old bike and get 95% of them new!
I have 18 other bikes and this is not always the case, finding ammerachi parts for a 1952 250 sprint or a 1962 honda 305 dream is near impossible!

Started putting gears back together and the rest of the engine.
Only had 1 minor setback, kinda funny.

I noticed that I had a steel bearing ball on the floor beneath my computer chair, assuming it had fallen out of the gear shaft when I was checking out my pics of how the gears went back on (I take lots of pics for myself), I put it on the shelf knowing I had an extra from going with the longer push rod.

After drilling out bushing on the clutch putting everything back together and closing it back up,I started putting all the outer parts back and started the clutch,after switching out the short pushrod for the long, i noticed in my ziplock bag I had a ball bearing left over! this meant I had two, huh? I had one beside the computer and one out in my shop in a ziplock bag!
I doulbe checked the clutch and only had one ball in it between the mushroom head and the new longer rod, my mind started thinking that I had just sealed the engine and may be missing a bearing from somewhere inside. I read the chapter in the manual to see if the bearing could have fallen out of somewhere else and the only other ball bearing that I could fined are in the pressed roller on the end of the gear shaft!
I sat down and had a stiff rum and pepsi while cursing I was gonna have to pull engine apart again and check all the roller bearings.
I went up stairs by the computer and grabbed the extra ball bearing I found on the floor and then started thinking this looked smaller than the push rod ball bearing so it had to be out of the roller! then I started thinking the roller bearings are usually pressed in and if it could fall out it would at least be cover in a bit of grease, right?
I then went to my littel girl and asked her what this little ball was, she replied "its from my magnectic connector set"
I am so glad I took the time to mix a drink and figure this out rather than rip into the engine right away!

On the right is the kids toy,lol.


Only other thing I found was the starter pinion and what position the horse clip was to be put in, I found a post on here that shows it is to the right of the original position.



when I get some more free time I shold be ready to put engine back into frame fairly quick and give her a test.

 

[XSLeo]

The "horse clip" is what most call the wishbone spring. In mid 75 they changed it. They started using heavier wire to make the clip out of. With the heavier wire they couldn't bend it tight enough to fit the notch on the case. So they moved it over a bit and now it sets beside the notch.
Nice job on the write up. Good pics.
Leo

 

[peanut]

thats answered the question I had about the horse clip position thanks Leo.

I have another question though relating to BBrown's engine .
Are all the acorn headed nuts in the right positions ?

In relation to the tightening sequence numbers, I was sure about 1,2,3 & 4 but not about 13?

Can anyone point me towards a Yamaha link or guide showing the correct position of the 6x acorn nuts and copper washers please.

 

[bbrown]

Wooot!!!! you tryin to say my nuts look funny? lol.
I'll try to find pic that I used for sequence.




hope this helps.

 

[peanut]

thanks BB I wanted the reference from a recognised source as so much of the stuff on the net is simply the same old stuff regurgitated with no original research or source stated

 

[Street Tracker]

Marking need to go in and change shifting forks and drums I'm thinking.